mXT336U 1.0 maXTouch 336-node Touchscreen Controller maXTouch(R) Adaptive Sensing Touchscreen Technology * Discrete/out-cell support including glass and PET filmbased sensors * On-cell/touch-on display support including TFT, IPS and OLED * Synchronization with display refresh timing capability * Support for standard (for example, Diamond) and proprietary sensor patterns (review of designs by Microchip recommended) * Noise suppression technology to combat ambient, charger noise, and power-line noise - Up to 240 Vpp between 1 Hz and 1 kHz sinusoidal waveform - Up to 20 Vpp between 1 kHz and 1 MHz sinusoidal waveform * Stylus Support - Supports passive stylus with 2.5 mm contact diameter, subject to configuration, stack up, and sensor design * Radiated Noise - Flexible and dynamic Tx burst frequency selection - Controlled Tx burst frequency drift over process and temperature range * Scan Speed - Up to 250Hz one finger reporting rate, subject to configuration - Initial touch latency <12 ms for first touch from idle, subject to configuration - Typical report rate for 10 touches 60 Hz (subject to configuration) - Configurable to allow for power and speed optimization Front Panel Material On-chip Gestures * Works with PET or glass, including curved profiles (configuration and stack-up to be approved by Microchip) * Glass 0.4 mm to 4.5 mm (dependent on screen size, touch size, configuration and stack-up) * Plastic 0.2 mm to 2.2 mm (dependent on screen size, touch size, configuration and stack-up) * Supports wake up/unlock gestures, including symbol recognition * Up to 14 X (transmit) lines and 24 Y (receive) lines (see Section 4.1 "Permitted Configurations") * A maximum of 336 nodes can be allocated to the touchscreen * Touchscreen size 5.47 inches (16:9 aspect ratio), assuming a sensor electrode pitch of 5 mm. Other sizes may be possible with different electrode pitches and appropriate sensor material * Multiple touch support with up to 10 concurrent touches tracked in real time Touch Sensor Technology Touch Performance * Moisture/Water Compensation - No false touch with condensation or water drop up to 22 mm diameter - One-finger tracking with condensation or water drop up to 22 mm diameter * Glove Support - Multiple-finger glove touches up to 1.5 mm thickness (subject to stack-up design) - Single-finger glove touch up to 5 mm thickness (subject to stack-up design) * Mutual capacitance and self capacitance measurements supported for robust touch detection 2019 Microchip Technology Inc. Keys * Up to 8 nodes can be allocated as mutual capacitance sensor keys (subject to other configurations) * Support for 3 Generic Keys in addition to the touchscreen array (subject to other configurations) * Adjacent Key Suppression (AKS) technology is supported for false key touch prevention Enhanced Algorithms * Lens bending algorithms to remove display noise * Touch suppression algorithms to remove unintentional large touches, such as palm * Palm Recovery Algorithm for quick restoration to normal state DS40001922C-page 1 MXT336U 1.0 Product Data Store Area * Up to 60 bytes of user-defined data can be stored during production Power Saving * Programmable timeout for automatic transition from active to idle states * Pipelined analog sensing detection and digital processing to optimize system power efficiency Application Interfaces * * * I2C-compatible slave mode: Standard/Fast mode 400 kHz Interrupt to indicate when a message is available SPI Debug Interface to read the real-time raw data for tuning and debugging purposes Power Supply * * * * Digital (Vdd) 3.3 V nominal Analog (AVdd) 3.3 V nominal Host interface I/O voltage (VddIO) 3.3 V nominal High voltage internal X line drive (XVdd) 6.6 V, with internal voltage pump Package * 56-pin XQFN 6 x 6 x 0.4 mm, 0.35 mm pitch Environmental Conditions * Operating temperature -40C to +85C Design Services * Review of device configuration, stack-up and sensor patterns * Custom firmware versions can be considered, such as specific gestures or proprietary OEM host communication protocols * Contact your Microchip representative for more information DS40001922C-page 2 2019 Microchip Technology Inc. MXT336U 1.0 CONNECTION AND CONFIGURATION INFORMATION GKEYY2/NOISE_IN/DBG2_DATA5 Y11 Y10 Y9 Y8 Y7 Y6 Y5 Y4 Y3 Y2 Y1 Y0 AVDD Pin Configuration - 56-pin XQFN 56 55 54 53 52 51 50 49 48 47 46 45 44 43 X0 1 42 GKEYY1/DBG2_DATA4 X1 2 41 GKEYY0/DBG_SS/DBG2_DATA3 X2 3 40 DS0/GKEYX0/DBG2_DATA2 X3 4 39 SCAN_OUT/DBG_CLK/DBG2_DATA1 X4 5 38 SYNC/DBG_DATA/DBG2_DATA0 X5 6 37 CHG/DBG2_FRAME X6 7 36 RESET X7 8 35 SCL Top View X8 9 34 SDA X9 10 33 TEST/DBG2_CLK X10 11 32 VDDIO X11 12 31 VDDCORE X12 13 30 VDD X13 14 29 EXTCAP0 2019 Microchip Technology Inc. Y23 Y22 Y21 Y20 Y19 Y18 Y17 Y16 Y15 Y14 Y13 Y12 EXTCAP1 XVDD 15 16 17 18 19 20 21 22 23 24 25 26 27 28 GND DS40001922C-page 3 MXT336U 1.0 TABLE 0-1: PIN LISTING - 56-PIN XQFN Pin Name Type 1 X0 S Supply Description XVdd X line connection If Unused... Leave open 2 X1 S XVdd X line connection Leave open 3 X2 S XVdd X line connection Leave open 4 X3 S XVdd X line connection Leave open 5 X4 S XVdd X line connection Leave open 6 X5 S XVdd X line connection Leave open 7 X6 S XVdd X line connection Leave open 8 X7 S XVdd X line connection Leave open 9 X8 S XVdd X line connection Leave open 10 X9 S XVdd X line connection Leave open 11 X10 S XVdd X line connection Leave open 12 X11 S XVdd X line connection Leave open 13 X12 S XVdd X line connection Leave open Leave open 14 X13 S XVdd X line connection 15 XVDD P XVdd X line drive power - 16 EXTCAP1 P - Voltage doubler - connect to EXTCAP0 via capacitor - 17 Y12 S AVdd Y line connection Leave open 18 Y13 S AVdd Y line connection Leave open 19 Y14 S AVdd Y line connection Leave open 20 Y15 S AVdd Y line connection Leave open 21 Y16 S AVdd Y line connection Leave open 22 Y17 S AVdd Y line connection Leave open 23 Y18 S AVdd Y line connection Leave open 24 Y19 S AVdd Y line connection Leave open 25 Y20 S AVdd Y line connection Leave open 26 Y21 S AVdd Y line connection Leave open 27 Y22 S AVdd Y line connection Leave open 28 Y23 S AVdd Y line connection Leave open 29 EXTCAP0 P - Voltage doubler - connect to EXTCAP1 via capacitor - 30 VDD P - Digital power - 31 VDDCORE P - Digital core power - 32 VDDIO P - Digital IO interface power - TEST - DBG2_CLK O 33 VddIO Reserved for factory use; pull up to VddIO Pull up to VddIO Secondary Debug Clock 34 SDA OD VddIO Serial Interface Data - 35 SCL OD VddIO Serial Interface clock - VddIO Reset low. Connection to host system is recommended 36 37 38 39 DS40001922C-page 4 RESET I CHG OD DBG2_FRAME O SYNC I DBG_DATA O DBG2_DATA0 O Secondary Debug Data 0 SCAN_OUT O Indicates touch scanning in progress. Polarity configurable DBG_CLK O DBG2_DATA1 O VddIO Pull up to VddIO State change interrupt Note: Briefly set (~100 ms) as an input after power-up/ reset for diagnostic purposes Pull up to VddIO Secondary Debug Frame External synchronization VddIO VddIO Primary Debug Data Primary Debug Clock - Leave open Secondary Debug Data 1 2019 Microchip Technology Inc. MXT336U 1.0 TABLE 0-1: Pin 40 41 42 43 PIN LISTING - 56-PIN XQFN (CONTINUED) Name Type Supply Description If Unused... Driven Shield; used as guard track between X/Y signals and ground DS0 S GKEYX0 S DBG2_DATA2 O Secondary Debug Data 2 GKEYY0 S Generic keys Y line DBG_SS O DBG2_DATA3 O Secondary Debug Data 3 GKEYY1 S Generic keys Y line DBG2_DATA4 O GKEYY2 S Vdd Vdd Vdd Leave open Generic keys X line Primary Debug SS line Leave open Leave open Secondary Debug Data 4 Generic keys Y line NOISE_IN I DBG2_DATA5 O 44 Y11 S AVdd Y line connection Leave open 45 Y10 S AVdd Y line connection Leave open 46 Y9 S AVdd Y line connection Leave open 47 Y8 S AVdd Y line connection Leave open 48 Y7 S AVdd Y line connection Leave open 49 Y6 S AVdd Y line connection Leave open 50 Y5 S AVdd Y line connection Leave open 51 Y4 S AVdd Y line connection Leave open 52 Y3 S AVdd Y line connection Leave open 53 Y2 S AVdd Y line connection Leave open 54 Y1 S AVdd Y line connection Leave open 55 Y0 S AVdd Y line connection Leave open 56 AVDD P - Analog power - Pad GND P - Exposed pad must be connected to GND - Key: I OD Input only Open drain output 2019 Microchip Technology Inc. Vdd Noise present input Leave open Secondary Debug Data 5 O P Output only Ground or power I/O S Input or output Sense pin DS40001922C-page 5 MXT336U 1.0 TABLE OF CONTENTS Connection and Configuration Information ........................................................................................................................... 3 Table of Contents .................................................................................................................................................................. 6 To Our Valued Customers .................................................................................................................................................... 7 1.0 Overview of mXT336U ............................................................................................................................................... 8 2.0 Schematics ................................................................................................................................................................. 9 3.0 Touchscreen Basics ................................................................................................................................................. 12 4.0 Sensor Layout .......................................................................................................................................................... 13 5.0 Power-up / Reset Requirements .............................................................................................................................. 17 6.0 Detailed Operation ................................................................................................................................................... 20 7.0 I2C Communications ................................................................................................................................................ 23 8.0 PCB Design Considerations ..................................................................................................................................... 29 9.0 Getting Started with mXT336U ................................................................................................................................. 33 10.0 Debugging and Tuning ............................................................................................................................................. 37 11.0 Specifications ........................................................................................................................................................... 38 12.0 Packaging Information ............................................................................................................................................... 48 Appendix A. Associated Documents .................................................................................................................................. 50 Appendix B. Revision History .............................................................................................................................................. 51 Product Identification System ............................................................................................................................................. 55 The Microchip Web Site ...................................................................................................................................................... 56 Customer Change Notification Service ............................................................................................................................... 56 Customer Support ............................................................................................................................................................... 56 DS40001922C-page 6 2019 Microchip Technology Inc. MXT336U 1.0 TO OUR VALUED CUSTOMERS It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and enhanced as new volumes and updates are introduced. If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via E-mail at docerrors@microchip.com. We welcome your feedback. Most Current Data Sheet To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at: http://www.microchip.com You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page. The last character of the literature number is the version number, (for example, DS30000000A is version A of document DS30000000). Errata An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision of silicon and revision of document to which it applies. To determine if an errata sheet exists for a particular device, please check with one of the following: * Microchip's Worldwide Web site; http://www.microchip.com * Your local Microchip sales office (see last page) When contacting Microchip, please specify which device, revision of silicon and data sheet (include literature number) you are using. Customer Notification System Register on our web site at http://www.microchip.com to receive the most current information on all of our products. 2019 Microchip Technology Inc. DS40001922C-page 7 MXT336U 1.0 1.0 OVERVIEW OF MXT336U The Microchip maXTouch family of touch controllers brings industry-leading capacitive touch performance to customer applications. The mXT336U features the latest generation of Microchip adaptive sensing technology that utilizes a hybrid mutual and self capacitive sensing system in order to deliver unparalleled touch features and a robust user experience. * Patented capacitive sensing method - The mXT336U uses a unique charge-transfer acquisition engine to implement Microchip's patented capacitive sensing method. Coupled with a state-of-the-art CPU, the entire touchscreen sensing solution can measure, classify and track a number of individual finger touches with a high degree of accuracy in the shortest response time. * Capacitive Touch Engine (CTE) - The mXT336U features an acquisition engine, which uses an optimal measurement approach to ensure almost complete immunity from parasitic capacitance on the receiver input lines. The engine includes sufficient dynamic range to cope with anticipated touchscreen self and mutual capacitances, which allows great flexibility for use with the Microchip proprietary sensor pattern designs. One- and two-layer ITO sensors are possible using glass or PET substrates. * Touch detection - The mXT336U allows for both mutual and self capacitance measurements, with the self capacitance measurements being used to augment the mutual capacitance measurements to produce reliable touch information. When self capacitance measurements are enabled, touch classification is achieved using both mutual and self capacitance touch data. This has the advantage that both types of measurement systems can work together to detect touches under a wide variety of circumstances. The system may be configured for various types of default measurements: - Mutual Capacitance Touch Default Idle - During idle mode, the device performs mutual capacitance touch scans. - Mutual Capacitance Touch Default Active - During active mode, when one or more touches are detected, the device performs mutual capacitance touch scans. Note that in both of the above cases, other scans (for example, self capacitance touch) may also be made depending on configuration. - Self Capacitance Touch Default Idle - During idle mode, the device performs self capacitance touch scans. - Self Capacitance Touch Default Active - During active mode, when a single touch is detected, the device performs self capacitance touch scans. If multiple touches are detected, the device performs mutual capacitance touch scans to process the touches. The system may be configured for different types of default measurements in idle and active modes. Mutual capacitance touch data is used wherever possible to classify touches as this has greater granularity than self capacitance measurements and provides positional information on touches. For this reason, multiple touches can only be determined by mutual capacitance touch data. In Self Capacitance Touch Default mode, if the self capacitance touch processing detects multiple touches, touchscreen processing is skipped until mutual capacitance touch data is available. Self capacitance measurements, on the other hand, allow for the detection of single touches in extreme cases, such as single thick glove touches, when touches can only be detected by self capacitance data and may be missed by mutual capacitance touch detection. * Display Noise Cancellation - A combination of analog circuitry, hardware noise processing, and firmware that combats display noise without requiring additional listening channels or synchronization to display timing. This enables the use of shieldless touch sensor stacks, including touch-on-lens. * Noise filtering - Hardware noise processing in the capacitive touch engine provides enhanced autonomous filtering and allows a broad range of noise profiles to be handled. The result is good performance in the presence of charger and LCD noise. * Processing power - The main CPU has two powerful microsequencer coprocessors under its control consuming low power. This system allows the signal acquisition, preprocessing, postprocessing and housekeeping to be partitioned in an efficient and flexible way. * Interpreting user intention - The Microchip hybrid mutual and self capacitance method provides unambiguous multitouch performance. Algorithms in the mXT336U provide optimized touchscreen position filtering for the smooth tracking of touches, responding to a user's intended touches while preventing false touches triggered by ambient noise, conductive material on the sensor surface, such as moisture, or unintentional touches from the user's resting palm or fingers. DS40001922C-page 8 2019 Microchip Technology Inc. MXT336U 1.0 2.0 SCHEMATICS 2.1 Schematic XQFN 56 Pins AVDD 22nF VDD 22nF 2.2uF GND 2.2uF VDDIO 1uF 22nF 22nF 1uF GND GND GND 31 32 30 56 15 22nF VDDIO 10k Rp Rp SCL 35 SDA 34 CHG 37 RESET 36 See Notes VDD AVDD EXTCAP1 10k 33 VDD VDDCORE 16 EXTCAP0 EXTCAP1 See Notes 10k 29 VDDIO Cd 2.2nF XVDD GND EXTCAP0 TEST/DBG2_CLK RESET Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8 Y9 Y10 Y11 Y12 Y13 Y14 Y15 Y16 Y17 Y18 Y19 Y20 Y21 Y22 Y23 DBG_DATA DBG_CLK 43 GKEYX0/DS0 40 SYNC 38 SCAN_OUT 39 NOTE: See "Connection and Configuration Information" for information on I/O pin supply GKEYY1/DBG2_DATA4 GKEYY2/NOISE_IN/DBG2_DATA5 GKEYX0/DS0/DBG2_DATA2 SYNC/DBG_DATA/DBG2_DATA0 SCAN_OUT/DBG_CLK/DBG2_DATA1 GND GKEYY2/NOISE_IN GKEYY0/DBG_SS/DBG2_DATA3 PAD 42 Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8 Y9 Y10 Y11 Y12 Y13 Y14 Y15 Y16 Y17 Y18 Y19 Y20 Y21 Y22 Y23 mXT336U DBG_SS GKEYY1 55 54 53 52 51 50 49 48 47 46 45 44 17 18 19 20 21 22 23 24 25 26 27 28 CHG/DBG2_FRAME GND 41 X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 SDA See Notes GKEYY0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 SCL Creset 10nF 10k X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 GND See Section 2.2 "Schematic Notes" 2019 Microchip Technology Inc. DS40001922C-page 9 MXT336U 1.0 2.2 Schematic Notes CAUTION! 2.2.1 The device may be permanently damaged if any XVDD pin is shorted to ground or high current is drawn from it. POWER SUPPLY The sense and I/O pins are supplied by the power rails on the device as listed in Table 0-1. This information is also indicated in "Connection and Configuration Information". s Table 0-1. Power Supply for Sense and I/O Pins Power Supply XVdd X drive lines AVdd Y sense lines VddIO RESET, SYNC, SDA, SCL, CHG, SCAN_OUT, DBG_CLK, DBG_DATA Vdd 2.2.2 Pins NOISE_IN, GKEYYn, GKEYX0, DS0, DBG_SS DECOUPLING CAPACITORS All decoupling capacitors must be X7R or X5R and placed less than 5 mm away from the balls for which they act as bypass capacitors. Pins of the same type can share a capacitor provided no pin is more than 10 mm from the capacitor. The schematics on the previous pages show the optimum capacitors required. The parallel combination of capacitors is recommended to give high and low frequency filtering, which is beneficial if the voltage regulators are likely to be some distance from the device (for example, If an active tail design is used). Note that this requires that the voltage regulator supplies for AVdd, Vdd and VddIO are clean and noise free. It also assumes that the track length between the capacitors and on-board power supplies is less than 50 mm. The number of base capacitors can be reduced if the pinout configuration means that sharing a bypass capacitor is possible (subject to the distance between the pins satisfying the conditions above and there being no routing difficulties). 2.2.3 PULL-UP RESISTORS The pull-up resistors shown in the schematic are suggested typical values and may be modified to meet the requirements of an individual customer design. This applies, in particular, to the I2C pull-up resistors (see Section 2.2.6 "I2C Interface"). 2.2.4 INTERNAL VOLTAGE PUMP The voltage pump requires one external capacitor: * EXTCAP0 must be connected to EXTCAP1 via a capacitor (Cd) Capacitor Cd should provide a capacitance of 2.2 nF. 2.2.5 VDDCORE VddCore is internally generated from the Vdd power supply. To guarantee stability of the internal voltage regulator, an external capacitor is required. The capacitor should have a value of 1 F. 2.2.6 I2C INTERFACE The schematic shows pull-up resistors on the SDA and SCL lines. The values of these resistors depends on the speed of the I2C interface. See Section 11.9 "I2C Specification" for details. Note that if a VddIO supply at the low end of the allowable range is used, the pull-up resistor values may need to be reduced. 2.2.7 MULTIPLE FUNCTION PINS Some pins may have multiple functions. In this case, only one function can be chosen and the circuit should be designed accordingly. DS40001922C-page 10 2019 Microchip Technology Inc. MXT336U 1.0 2.2.8 PRIMARY DEBUG LINES The DBG_CLK, DBG_DATA and DBG_SS Lines form the SPI Debug Interface. These pins should be routed to test points on all designs, such that they can be connected to external hardware during system development. See also Section 10.1 "SPI Debug Interface". Note that the debug lines may share pins with other functionality. Only one function for each pin can be chosen and the circuit should be designed accordingly. Note that the pull-up resistor for DBG_SS in the schematics is optional and should be present only if the line is used as DBG_SS. The DBG_CLK, DBG_DATA and DBG_SS lines should not be connected to power or GND. 2019 Microchip Technology Inc. DS40001922C-page 11 MXT336U 1.0 3.0 TOUCHSCREEN BASICS 3.1 Sensor Construction A touchscreen is usually constructed from a number of transparent electrodes. These are typically on a glass or plastic substrate. They can also be made using non-transparent electrodes, such as copper or carbon. Electrodes are constructed from Indium Tin Oxide (ITO) or metal mesh. Thicker electrodes yield lower levels of resistance (perhaps tens to hundreds of / square) at the expense of reduced optical clarity. Lower levels of resistance are generally more compatible with capacitive sensing. Thinner electrodes lead to higher levels of resistance (perhaps hundreds to thousands of /square) with some of the best optical characteristics. Interconnecting tracks can cause problems. The excessive RC time constants formed between the resistance of the track and the capacitance of the electrode to ground can inhibit the capacitive sensing function. In such cases, the tracks should be replaced by screen printed conductive inks (non-transparent) outside the touchscreen viewing area. 3.2 Electrode Configuration The specific electrode designs used in Microchip touchscreens are the subject of various patents and patent applications. Further information is available on request. The device supports various configurations of electrodes as summarized in Section 4.0 "Sensor Layout". 3.3 Scanning Sequence All nodes are scanned in sequence by the device. There is a full parallelism in the scanning sequence to improve overall response time. The nodes are scanned by measuring capacitive changes at the intersections formed between the first X line and all the Y lines. Then the intersections between the next X line and all the Y lines are scanned, and so on, until all X and Y combinations have been measured. The device can be configured in various ways. It is possible to disable some nodes so that they are not scanned at all. This can be used to improve overall scanning time. 3.4 3.4.1 Touchscreen Sensitivity ADJUSTMENT Sensitivity of touchscreens can vary across the extents of the electrode pattern due to natural differences in the parasitic capacitance of the interconnections, control chip, and so on. An important factor in the uniformity of sensitivity is the electrode design itself. It is a natural consequence of a touchscreen pattern that the edges form a discontinuity and hence tend to have a different sensitivity. The electrodes at the far edges do not have a neighboring electrode on one side and this affects the electric field distribution in that region. A sensitivity adjustment is available for the whole touchscreen. This adjustment is a basic algorithmic threshold that defines when a node is considered to have enough signal change to qualify as being in detect. 3.4.2 MECHANICAL STACKUP The mechanical stackup refers to the arrangement of material layers that exist above and below a touchscreen. The arrangement of the touchscreen in relation to other parts of the mechanical stackup has an effect on the overall sensitivity of the screen. QMatrix technology has an excellent ability to operate in the presence of ground planes close to the sensor. QMatrix sensitivity is attributed more to the interaction of the electric fields between the transmitting (X) and receiving (Y) electrodes than to the surface area of these electrodes. For this reason, stray capacitance on the X or Y electrodes does not strongly reduce sensitivity. Front panel dielectric material has a direct bearing on sensitivity. Plastic front panels are usually suitable up to about 1.2 mm, and glass up to about 2.5 mm (dependent upon the screen size and layout). The thicker the front panel, the lower the signal-to-noise ratio of the measured capacitive changes and hence the lower the resolution of the touchscreen. In general, glass front panels are near optimal because they conduct electric fields almost twice as easily as plastic panels. NOTE Care should be taken using ultra-thin glass panels as retransmission effects can occur, which can significantly degrade performance. DS40001922C-page 12 2019 Microchip Technology Inc. MXT336U 1.0 4.0 SENSOR LAYOUT The specific electrode designs used in Microchip touchscreens are the subject of various patents and patent applications. Further information is available on request. The physical matrix can be configured to have one or more touch objects. These are configured using the appropriate touch objects (Multiple Touch Touchscreen and Key Array). It is not mandatory to have all the allowable touch objects present. The objects are disabled by default so only those that you wish to use need to be enabled. The device supports various configurations of electrodes as summarized below: * Touchscreen: 14 X x 24 Y maximum (subject to other configurations) * Standard Keys: Up to 8 keys in an X/Y grid (Key Array), implemented using standard sense lines * Generic Keys: Up to 3 keys in an X/Y grid (Key Array), implemented using the Generic Key lines Note that the 3 nodes provided by the Generic Key lines are in addition to the maximum 336 nodes permitted on the device. Note also that the Key Array must contain either Generic Key lines or standard sense lines, but not both. When designing the physical layout of the touch panel, the following rules must be obeyed: * Each touch object should be a regular rectangular shape in terms of the lines it uses. * A Touchscreen object cannot share an X or Y line with another touch object if self-capacitance measurements are enabled. * The Touchscreen must start at X0, Y0. * For mutual capacitance touchscreens, the following applies: - The number of X lines supported must be 3 or higher. If Dual X Drive is enabled for use in the Noise Suppression T72 object, the minimum is 4 X lines - The number of Y lines supported must be 3 or higher * For self capacitance touchscreens, the following applies: - The number of X lines supported must be in the range 8 to 14 - The number of Y lines supported must be one of: 24, 23, 20, 16, 12 or 8 * It is recommended that a standard Key Array should occupy the highest X and Y lines within the XY touchscreen matrix. 4.1 Permitted Configurations The permitted configurations are shown in Table 4-1 and Table 4-2. TABLE 4-1: Number of Y Lines 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Key: PERMITTED TOUCHSCREEN CONFIGURATIONS - MUTUAL CAPACITANCE 14 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y X 13 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y 12 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y 11 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y 10 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y 9 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Number of X Lines 8 7 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y 6 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y 5 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y 4 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y 3 X X X X X X X X X X X X X X X X X X X X X X 2 1 Configuration supported Configuration supported, but only if dual X is not used Configuration not supported 2019 Microchip Technology Inc. DS40001922C-page 13 MXT336U 1.0 TABLE 4-2: Number of Y Lines 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Key: 4.2 PERMITTED TOUCHSCREEN CONFIGURATIONS - SELF CAPACITANCE X Lines 14 Y Y 13 Y Y 12 Y Y 11 Y Y 10 Y Y 9 Y Y 8 Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y 7 6 5 4 3 2 1 Configuration supported Configuration not supported Screen Size Table 4-3 lists some typical screen size and electrode pitch combinations to achieve various aspect ratios. TABLE 4-3: TYPICAL SCREEN SIZES Screen Diagonal (Inches) Aspect Ratio 4.3 Matrix Size Node Count 4 mm Pitch 5 mm Pitch 6 mm Pitch 16:10 X = 14, Y = 23 322 4.24 5.3 6.36 16:9 X = 14, Y = 24 336 4.38 5.47 6.56 4:3 X = 14, Y = 19 266 3.72 4.65 5.58 2:1 X = 12, Y = 24 288 4.23 5.28 6.34 Standard Key Array For optimal performance in terms of cycle time overhead, it is recommended that the number of X (drive) lines used for the standard Key Array is kept to the minimum and designs should favor using Y lines where possible (observing any restriction on the number of Y lines that can be used). Figure 4-1 on page 15 shows an example layout for a Touchscreen with a Key Array of 1 X x 4 Y lines. Note that in this case using 1 X x 4 Y lines for the Key Array would give better performance than using 4 X x 1 Y lines. DS40001922C-page 14 2019 Microchip Technology Inc. MXT336U 1.0 FIGURE 4-1: EXAMPLE LAYOUT - OPTIMAL CYCLE TIME X13 Keys 1Xx4Y Y23 XY Matrix Matrix XY (Standard Sense (Standard Lines) Y20 Y19 XY Matrix Multiple Touch (Standard Sense Touchscreen (13 Lines) X x 20 Y) Y0 X0 X12 If, however, the intention is to preserve a larger touchscreen size and maintain an optimal aspect ratio, then using equal X and Y lines for the key array can be considered, as in Figure 4-2 on page 15. FIGURE 4-2: EXAMPLE LAYOUT - OPTIMAL ASPECT RATIO X12 X13 Y23 XY Matrix (Standard Sense Lines) Keys 2Xx2Y Y22 Y21 Multiple Touch XY Matrix (Standard Sense Touchscreen (12 Lines) X x 22 Y) Y0 X0 2019 Microchip Technology Inc. X11 DS40001922C-page 15 MXT336U 1.0 4.4 Generic Key Array The Generic Key lines can be used to form 3 mutual capacitance nodes that can be used to form a Key Array only. Using the Generic Keys may add extra noise line measurements, which will impact power consumption and timings. It is therefore recommended that, where spare mutual capacitance sense lines are available, the sense lines are used to form a standard Key Array in preference to using the Generic Key lines. FIGURE 4-3: EXAMPLE LAYOUT - TOUCHSCREEN WITH GENERIC KEYS GKEYY2 Generic Key Array 1Xx3Y GKEYY0 GKEYX0 Y23 Multiple XYTouch atrix (Standard Se touchscreen (13nse X xLines) 24 Y) XY Matrix (Standard Sense Lines) Y0 X0 DS40001922C-page 16 X13 2019 Microchip Technology Inc. MXT336U 1.0 5.0 POWER-UP / RESET REQUIREMENTS 5.1 Power-on Reset There is an internal Power-on Reset (POR) in the device. If an external reset is to be used the device must be held in RESET (active low) while the digital (Vdd) analog (AVdd) and I/O (VddIO) power supplies are powering up. The supplies must have reached their nominal values before the RESET signal is deasserted (that is, goes high). This is shown in Figure 5-1. See Section 11.2 "Recommended Operating Conditions" for nominal values for Vdd, VddIO, and AVdd. FIGURE 5-1: POWER SEQUENCING ON THE MXT336U AVdd Vdd VddIO (VddIO) RESET > 90 ns Note: When using external RESET at power-up, VddIO must not be enabled after Vdd After power-up, the device typically takes 35 ms before it is ready to start communications. If the RESET line is released before the AVdd supply has reached its nominal voltage (see Figure 5-2 on page 18), then some additional operations need to be carried out by the host. There are two options open to the host controller: * Start the part in deep sleep mode and then send the command sequence to set the cycle time to wake the part and allow it to run normally. Note that in this case a calibration command is also needed. * Send a RESET command. 2019 Microchip Technology Inc. DS40001922C-page 17 MXT336U 1.0 FIGURE 5-2: POWER SEQUENCING ON THE MXT336U - LATE RISE ON AVDD RESET deasserted before AVdd at nominal level (Nom) AVdd Vdd (Nom) VddIO (Nom) (VddIO) RESET The RESET pin can be used to reset the device whenever necessary. The RESET pin must be asserted low for at least 90 ns to cause a reset. After releasing the RESET pin the device typically takes 38 ms before it is ready to start communications. It is recommended to connect the RESET pin to a host controller to allow it to initiate a full hardware reset without requiring a power-down. Make sure that any lines connected to the device are below or equal to Vdd during power-up. For example, if RESET is supplied from a different power domain to the VDDIO pin, make sure that it is held low when Vdd is off. If this is not done, the RESET signal could parasitically couple power via the RESET pin into the Vdd supply. Note that the voltage level on the RESET pin of the device must never exceed VddIO (digital supply voltage). A software RESET command (using the Command Processor T6 object) can be used to reset the chip. A software reset takes typically 55 ms. After the chip has finished it asserts the CHG line to signal to the host that a message is available. The reset flag is set in the Message Processor object to indicate to the host that it has just completed a reset cycle. This bit can be used by the host to detect any unexpected brownout events. This allows the host to take any necessary corrective actions, such as reconfiguration. A checksum check is performed on the configuration settings held in the nonvolatile memory. If the checksum does not match a stored copy of the last checksum, then this indicates that the settings have become corrupted. This is signaled to the host by setting the configuration error bit in the message data for the Command Processor T6 object. Note that the CHG line is briefly set as an input during power-up or reset. It is therefore particularly important that the line should be allowed to float high via the CHG line pull-up resistor during this period. It should not be driven by the host (see Table 11.6.3 on page 45). At power-on, the device performs a self-test routine (using the Self Test T25 object) to check for shorts that might cause damage to the device. WARNING 5.2 The device should be reset only by using the RESET line. If an attempt is made to reset by removing the power from the device without also sending the signal lines low, power will be drawn from the interface lines and the device will not reset correctly. Power-up and Reset Sequence - VddIO Enabled after Vdd The power-up sequence that can be used in applications where VddIO must be powered up after Vdd, is shown in Figure 5-3 on page 19. In this case the communication interface to the maXTouch device is not driven by the host system. The RESET and CHG pins are connected to VddIO using suitable pull-up resistors. Vdd is powered up, followed by VddIO, no more than 10 ms after Vdd. Due to the pull-up resistors, RESET and CHG will rise with VddIO. The internal POR system ensures reliable boot up of the device and the CHG line will go low approximately 35 ms after Vdd to notify the host that the device is ready to start communication. DS40001922C-page 18 2019 Microchip Technology Inc. MXT336U 1.0 FIGURE 5-3: POWER-UP SEQUENCE < 10 ms Vdd VddIO RESET No External drive. Pull-up resistor to VddIO on RESET and CHG when VddIO rises, RESET and CHG rise with VddIO CHG > 90 ms 5.2.1 SUMMARY The power-up and reset requirements for the maXTouch devices are summarized in Table 5-1. TABLE 5-1: POWER-UP AND RESET REQUIREMENTS Condition External RESET VddIO Delay (After Vdd) 1 Low at Power-up 2 Not driven 2019 Microchip Technology Inc. AVdd Power-Up Comments 0 ms Before RESET is released <10 ms Before VddIO If AVdd bring-up is delayed then additional actions will be required by the host. See notes in Figure 5-1 on page 17 DS40001922C-page 19 MXT336U 1.0 6.0 DETAILED OPERATION 6.1 Touch Detection The mXT336U allows for both mutual and self capacitance measurements, with the self capacitance measurements being used to augment the mutual capacitance measurements to produce reliable touch information. When self capacitance measurements are enabled, touch classification is achieved using both mutual and self capacitance touch data. This has the advantage that both types of measurement systems can work together to detect touches under a wide variety of circumstances. Mutual capacitance touch data is used wherever possible to classify touches as this has greater granularity than self capacitance measurements and provides positional information on touches. Self capacitance measurements, on the other hand, allow for the detection of single touches in extreme cases, such as single thick glove touches, when touches can only be detected by self capacitance data and may be missed by mutual capacitance touch detection. 6.2 Operational Modes The device operates in two modes: Active (touch detected) and Idle (no touches detected). Both modes operate as a series of burst cycles. Each cycle consists of a short burst (during which measurements are taken) followed by an inactive sleep period. The difference between these modes is the length of the cycles. Those in idle mode typically have longer sleep periods. The cycle length is configured using the IDLEACQINT and ACTVACQINT settings in the Power Configuration T7. In addition, an Active to Idle Timeout setting is provided. 6.3 Detection Integrator The device features a touch detection integration mechanism. This acts to confirm a detection in a robust fashion. A counter is incremented each time a touch has exceeded its threshold and has remained above the threshold for the current acquisition. When this counter reaches a preset limit the sensor is finally declared to be touched. If, on any acquisition, the signal is not seen to exceed the threshold level, the counter is cleared and the process has to start from the beginning. The detection integrator is configured using the appropriate touch objects (Multiple Touch Touchscreen T100, Key Array T15). 6.4 Sensor Acquisition The charge time is set using the Acquisition Configuration T8 object. A number of factors influence the acquisition time for a single drive line and the total acquisition time for the sensor as a whole must not exceed 250 ms. If this condition is not met, a SIGERR will be reported. Care should be taken to configure all the objects that can affect the measurement timing, for example, Acquisition Configuration T8, CTE Configuration T46 and Self Capacitance Configuration T111, so that these limits are not exceeded. 6.5 Calibration Calibration is the process by which a sensor chip assesses the background capacitance on each node. Nodes are only calibrated on reset and when: * The node is enabled (that is, activated) or * The node is already enabled and one of the following applies: - The node is held in detect for longer than the Touch Automatic Calibration setting (TCHAUTOCAL in the Acquisition Configuration T8 object) - The signal delta on a node is at least the touch threshold (TCHTHR - TCHHYST) in the anti-touch direction, while it meets the criteria in the Touch Recovery Processes that results in a recalibration and Self Capacitance Configuration T111 - The host issues a recalibrate command - Certain configuration settings are changed DS40001922C-page 20 2019 Microchip Technology Inc. MXT336U 1.0 A status message is generated on the start and completion of a calibration. Note that the device performs a global calibration; that is, all the nodes are calibrated together. 6.6 Digital Filtering and Noise Suppression The mXT336U supports on-chip filtering of the acquisition data received from the sensor. Specifically, the Noise Suppression T72 object provides an algorithm to suppress the effects of noise (for example, from a noisy charger plugged into the user's product). This algorithm can automatically adjust some of the acquisition parameters on-the-fly to filter the analog-to-digital conversions (ADCs) received from the sensor. Additional noise suppression is provided by the Self Capacitance Noise Suppression T108 object. Similar in both design and configuration to the Noise Suppression T72 object, the Self Capacitance Noise Suppression T108 object is the noise suppression interface for self capacitance touch measurements. Noise suppression is triggered when a noise source is detected. * A hardware trigger can be implemented using the NOISE_IN pin. * The host driver code can indicate when a noise source is present. * The noise suppression is also triggered based on the noise levels detected using internal line measurements.The Noise Suppression T72 and Self Capacitance Noise Suppression T108 object selects the appropriate controls to suppress the noise present in the system. 6.7 Shieldless Support and Display Noise Suppression The mXT336U can support shieldless sensor design even with a noisy LCD. Display noise suppression allows the device to overcome display noise simultaneously with external noise. This feature is based on filtering provided by the Lens Bending T65 object (see Section 6.10 "Lens Bending"). 6.8 Retransmission Compensation The device can limit the undesirable effects on the mutual capacitance touch signals caused by poor device coupling to ground, such as poor sensitivity and touch break-up. This is achieved using the Retransmission Compensation T80 object. This object can be configured to allow the touchscreen to compensate for signal degradation due to these undesirable effects. If self capacitance measurements are also scheduled, the Retransmission Compensation T80 object will use the resultant data to enhance the compensation process. The Retransmission Compensation T80 object is also capable of compensating for water presence on the sensor if self capacitance measurements are scheduled. In this case, both mutual capacitance and self capacitance measurements are used to detect moisture and then, once moisture is detected, self capacitance measurements are used to detect single touches in the presence of moisture. 6.9 Grip Suppression The device has two grip suppression mechanisms to suppress false detections from a user's grip. Mutual grip suppression works by specifying a boundary around a touchscreen, within which touches can be suppressed whilst still allowing touches in the center of the touchscreen. This ensures that a "rolling" hand touch (such as when a user grips a mobile device) is suppressed. A "real" (finger) touch towards the center of the screen is allowed. Mutual grip suppression is configured using the Grip Suppression T40 object. There is one instance of the Grip Suppression T40 object for each Multiple Touch Touchscreen T100 object present on the device. Self Capacitance grip suppression works by looking for characteristic shapes in the self capacitance measurement along the touchscreen boundary, and thereby distinguishing between a grip and a touch further into the sensor. 6.10 Lens Bending The device supports algorithms to eliminate disturbances from the measured signal. When the sensor suffers from the screen deformation (lens bending) the signal values acquired by normal procedure are corrupted by the disturbance component (bend). The amount of bend depends on: * The mechanical and electrical characteristics of the sensor * The amount and location of the force applied by the user touch to the sensor 2019 Microchip Technology Inc. DS40001922C-page 21 MXT336U 1.0 The Lens Bending T65 object measures the bend component and compensates for any distortion caused by the bend. As the bend component is primarily influenced by the user touch force, it can be used as a secondary source to identify the presence of a touch. The additional benefit of the Lens Bending T65 object is that it will eliminate LCD noise as well. 6.11 Glove Detection The device has glove detection algorithms that process the measurement data received from the touchscreen classifying touches as potential gloved touches. The Glove Detection T78 object is used to detect glove touches. In Normal Mode the Glove Detection T78 object applies vigorous glove classification to small signal touches to minimize the effect of unintentional hovering finger reporting. Once a gloved touch is found, the Glove Detection T78 object enters Glove Confidence Mode. In this mode the device expects the user to be wearing gloves so the classification process is much less stringent. 6.12 Stylus Support The mXT336U allows for the particular characteristics of passive stylus touches, whilst still allowing conventional finger touches to be detected. The touch sensitivity and threshold controls for stylus touches are configured separately from those for conventional finger touches so that both types of touches can be accommodated. Stylus support ensures that the small touch area of a stylus registers as a touch, as this would otherwise be considered too small for the touchscreen. Additionally, there are controls to distinguish a stylus touch from an unwanted approaching finger (such as on the hand holding the stylus). Passive stylus touches are configured by the Passive Stylus T47 object. There is one instance of the Passive Stylus T47 object for each Multiple Touch Touchscreen T100 object present on the device. 6.13 Unintentional Touch Suppression The Touch Suppression T42 object provides a mechanism to suppress false detections from unintentional touches from a large body area, such as from a face, ear or palm. The Touch Suppression T42 object also provides Maximum Touch Suppression to suppress all touches if more than a specified number of touches has been detected. There is one instance of the Touch Suppression T42 object for each Multiple Touch Touchscreen T100 object present on the device. 6.14 Adjacent Key Suppression Technology Adjacent Key Suppression (AKS) technology is a patented method used to detect which touch object is touched when objects are located close together. A touch in a group of AKS objects is only indicated on the object in that group that is touched first. This is assumed to be the intended object. Once an object in an AKS group is in detect, there can be no further detections within that group until the object is released. Objects can be in more than one AKS group. Note that AKS technology works best when it operates in conjunction with a detect integration setting of several acquisition cycles. The device has two levels of AKS. The first level works between the touch objects (Multiple Touch Touchscreen T100 and Key Array T15). The touch objects are assigned to AKS groups. If a touch occurs within one of the touch objects in a group, then touches within other objects inside that group are suppressed. For example, if a touchscreen and a Key Array are placed in the same AKS group, then a touch in the touchscreen will suppress touches in the Key Array, and vice versa. The second level of AKS is internal AKS within an individual Key Array object (note that internal AKS is not present on other types of touch objects, only a Key Array T15). If internal AKS is enabled, then when one key is touched, touches on all the other keys within the Key Array are suppressed. AKS is configured using the touch objects (Multiple Touch Touchscreen T100 or Key Array T15). NOTE If a touch is in detect and then AKS is enabled, that touch will not be forced out of detect. It will not go out of detect until the touch is released. AKS will then operate normally. This applies to both levels of AKS. DS40001922C-page 22 2019 Microchip Technology Inc. MXT336U 1.0 7.0 I2C COMMUNICATIONS The device can use an I2C interface for communication. The I2C interface is used in conjunction with the CHG line. The CHG line going active signifies that a new data packet is available. This provides an interrupt-style interface and allows the device to present data packets when internal changes have occurred. 7.1 I2C Address The device supports one I2C device address - 0x4A. The I2C address is shifted left to form the SLA+W or SLA+R address when transmitted over the I2C interface, as shown in Table 7-1. TABLE 7-1: Bit 7 FORMAT OF AN I2C ADDRESS Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Address: 0x4A 7.2 Bit 0 Read/write Writing To the Device A WRITE cycle to the device consists of a START condition followed by the I2C address of the device (SLA+W). The next two bytes are the address of the location into which the writing starts. The first byte is the Least Significant Byte (LSByte) of the address, and the second byte is the Most Significant Byte (MSByte). This address is then stored as the address pointer. Subsequent bytes in a multi-byte transfer form the actual data. These are written to the location of the address pointer, location of the address pointer + 1, location of the address pointer + 2, and so on. The address pointer returns to its starting value when the WRITE cycle STOP condition is detected. Figure 7-1 shows an example of writing four bytes of data to contiguous addresses starting at 0x1234. FIGURE 7-1: START EXAMPLE OF A FOUR-BYTE WRITE STARTING AT ADDRESS 0X1234 SLA+W 0x34 0x12 0x96 Write Address (LSB MSB) 7.3 0x9B 0xA0 0xA5 STOP Write Data I2C Writes in Checksum Mode In I2C checksum mode an 8-bit CRC is added to all I2C writes. The CRC is sent at the end of the data write as the last byte before the STOP condition. All the bytes sent are included in the CRC, including the two address bytes. Any command or data sent to the device is processed even if the CRC fails. To indicate that a checksum is to be sent in the write, the most significant bit of the MSByte of the address is set to 1. For example, the I2C command shown in Figure 7-2 writes a value of 150 (0x96) to address 0x1234 with a checksum. The address is changed to 0x9234 to indicate checksum mode. FIGURE 7-2: EXAMPLE OF A WRITE TO ADDRESS 0X1234 WITH A CHECKSUM START SLA+W 0x34 0x92 Write Address (LSB, MSB) 2019 Microchip Technology Inc. 0x96 Checksum STOP Write Data DS40001922C-page 23 MXT336U 1.0 7.4 Reading From the Device Two I2C bus activities must take place to read from the device. The first activity is an I2C write to set the address pointer (LSByte then MSByte). The second activity is the actual I2C read to receive the data. The address pointer returns to its starting value when the read cycle NACK is detected. It is not necessary to set the address pointer before every read. The address pointer is updated automatically after every read operation. The address pointer will be correct if the reads occur in order. In particular, when reading multiple messages from the Message Processor T5 object, the address pointer is automatically reset to allow continuous reads (see Section 7.5 "Reading Status Messages with DMA"). The WRITE and READ cycles consist of a START condition followed by the I2C address of the device (SLA+W or SLA+R respectively). Note that in this mode, calculating a checksum of the data packets is not supported. Figure 7-3 shows the I2C commands to read four bytes starting at address 0x1234. FIGURE 7-3: EXAMPLE OF A FOUR-BYTE READ STARTING AT ADDRESS 0X1234 Set Address Pointer START SLA+W 0x34 0x12 STOP Read Address (LSB, MSB) Read Data START SLA+R 0x96 0x9B 0xA0 0xA5 STOP Read Data 7.5 Reading Status Messages with DMA The device facilitates the easy reading of multiple messages using a single continuous read operation. This allows the host hardware to use a direct memory access (DMA) controller for the fast reading of messages, as follows: 1. 2. 3. 4. 5. 6. 7. The host uses a write operation to set the address pointer to the start of the Message Count T44 object, if necessary. Note that the STOP condition at the end of the read resets the address pointer to its initial location, so it may already be pointing at the Message Count T44 object following a previous message read. If a checksum is required on each message, the most significant bit of the MSByte of the read address must be set to 1. The host starts the read operation of the message by sending a START condition. The host reads the Message Count T44 object (one byte) to retrieve a count of the pending messages. The host calculates the number of bytes to read by multiplying the message count by the size of the Message Processor T5 object. Note that the host should have already read the size of the Message Processor T5 object in its initialization code. Note that the size of the Message Processor T5 object as recorded in the Object Table includes a checksum byte. If a checksum has not been requested, one byte should be deducted from the size of the object. That is: number of bytes = count x (size - 1). The host reads the calculated number of message bytes. It is important that the host does not send a STOP condition during the message reads, as this will terminate the continuous read operation and reset the address pointer. No START and STOP conditions must be sent between the messages. The host sends a STOP condition at the end of the read operation after the last message has been read. The NACK condition immediately before the STOP condition resets the address pointer to the start of the Message Count T44 object. DS40001922C-page 24 2019 Microchip Technology Inc. MXT336U 1.0 Figure 7-4 shows an example of using a continuous read operation to read three messages from the device without a checksum. Figure 7-5 on page 26 shows the same example with a checksum. FIGURE 7-4: CONTINUOUS MESSAGE READ EXAMPLE - NO CHECKSUM Set Address Pointer START LSB SLA+W MSB STOP Start Address of Message Count Object Read Message Count Continuous Read START SLA+R Count = 3 Message Count Object Read Message Data (size - 1) bytes Report ID Data Data Message Processor Object - Message # 1 Report ID Data Data Message Processor Object - Message # 2 Report ID Data Data STOP Message Processor Object - Message # 3 2019 Microchip Technology Inc. DS40001922C-page 25 MXT336U 1.0 FIGURE 7-5: CONTINUOUS MESSAGE READ EXAMPLE - I2C CHECKSUM MODE Set Address Pointer START SLA+W LSB MSB | 0x80 Checksum STOP Start Address of Message Count Object Read Message Count Continuous Read START SLA+R Count = 3 Message Count Object Read Message Data size bytes Report ID Data Data Checksum Message Processor Object - Message # 1 Report ID Data Data Checksum Message Processor Object - Message # 2 Report ID Data Data Checksum STOP Message Processor Object - Message # 3 There are no checksums added on any other I2C reads. An 8-bit CRC can be added, however, to all I2C writes, as described in Section 7.3 "I2C Writes in Checksum Mode". An alternative method of reading messages using the CHG line is given in Section 7.6 "CHG Line". 7.6 CHG Line The CHG line is an active-low, open-drain output that is used to alert the host that a new message is available in the Message Processor T5 object. This provides the host with an interrupt-style interface with the potential for fast response times. It reduces the need for wasteful I2C communications. The CHG line should always be configured as an input on the host during normal usage. This is particularly important after power-up or reset (see Section 5.0 "Power-up / Reset Requirements"). A pull-up resistor is required to VddIO (see Section 2.0 "Schematics"). The CHG line operates in two modes, as defined by the Communications Configuration T18 object. DS40001922C-page 26 2019 Microchip Technology Inc. MXT336U 1.0 CHG LINE MODES FOR I2C-COMPATIBLE TRANSFERS FIGURE 7-6: Mode 0 I2C Interface START SLA-R ACK B0 B1 ... Bn B0 B1 ... Bn Message #1 Message #2 CHG Line ... NACK B0 B1 ... Bn STOP Message #m ... CHG line high or low; see text Mode 1 I2C Interface START SLA-R B0 B1 ... Bn B0 B1 ... Bn Message #1 Message #2 ... ACK B0 B1 ... Bn STOP Message #m CHG Line ... CHG line high or low; see text In Mode 0 (edge-triggered operation): 1. 2. 3. The CHG line goes low to indicate that a message is present. The CHG line goes high when the first byte of the first message (that is, its report ID) has been sent and acknowledged (ACK sent) and the next byte has been prepared in the buffer. The STOP condition at the end of an I2C transfer causes the CHG line to stay high if there are no more messages. Otherwise the CHG line goes low to indicate a further message. Note that Mode 0 also allows the host to continually read messages by simply continuing to read bytes back without issuing a STOP condition. Message reading should end when a report ID of 255 ("invalid message") is received. Alternatively the host ends the transfer by sending a NACK after receiving the last byte of a message, followed by a STOP condition. If there is another message present, the CHG line goes low again, as in step 1. In this mode the state of the CHG line does not need to be checked during the I2C read. In Mode 1 (level-triggered operation): 1. 2. 3. The CHG line goes low to indicate that a message is present. The CHG line remains low while there are further messages to be sent after the current message. The CHG line goes high again only once the first byte of the last message (that is, its report ID) has been sent and acknowledged (ACK sent) and the next byte has been prepared in the output buffer. Mode 1 allows the host to continually read the messages until the CHG line goes high, and the state of the CHG line determines whether or not the host should continue receiving messages from the device. NOTE The state of the CHG line should be checked only between messages and not between the bytes of a message. The precise point at which the CHG line changes state cannot be predicted and so the state of the CHG line cannot be guaranteed between bytes. The Communications Configuration T18 object can be used to configure the behavior of the CHG line. In addition to the CHG line operation modes described above, this object allows direct control over the state of the CHG line. 7.7 SDA and SCL The I2C bus transmits data and clock with SDA and SCL, respectively. These are open-drain. The device can only drive these lines low or leave them open. The termination resistors (Rp) pull the line up to VddIO if no I2C device is pulling it down. The termination resistors should be chosen so that the rise times on SDA and SCL meet the I2C specifications for the interface speed being used, bearing in mind other loads on the bus. For best latency performance, it is recommended that no other devices share the I2C bus with the maXTouch controller. 2019 Microchip Technology Inc. DS40001922C-page 27 MXT336U 1.0 7.8 Clock Stretching The device supports clock stretching in accordance with the I2C specification. It may also instigate a clock stretch if a communications event happens during a period when the device is busy internally. The maximum clock stretch is approximately 10 - 15 ms. DS40001922C-page 28 2019 Microchip Technology Inc. MXT336U 1.0 8.0 PCB DESIGN CONSIDERATIONS 8.1 Introduction The following sections give the design considerations that should be adhered to when designing a PCB layout for use with the mXT336U. Of these, power supply and ground tracking considerations are the most critical. By observing the following design rules, and with careful preparation for the PCB layout exercise, designers will be assured of a far better chance of success and a correctly functioning product. 8.2 Printed Circuit Board Microchip recommends the use of a four-layer printed circuit board for mXT336U applications. This, together with careful layout, will ensure that the board meets relevant EMC requirements for both noise radiation and susceptibility, as laid down by the various national and international standards agencies. 8.2.1 PCB CLEANLINESS Modern no-clean-flux is generally compatible with capacitive sensing circuits. CAUTION! 8.3 8.3.1 If a PCB is reworked to correct soldering faults relating to any device, or to any associated traces or components, be sure that you fully understand the nature of the flux used during the rework process. Leakage currents from hygroscopic ionic residues can stop capacitive sensors from functioning. If you have any doubts, a thorough cleaning after rework may be the only safe option. Power Supply SUPPLY QUALITY While the device has good Power Supply Rejection Ratio properties, poorly regulated and/or noisy power supplies can significantly reduce performance. Particular care should be taken of the AVdd supply, as it supplies the sensitive analog stages in the device. 8.3.2 SUPPLY RAILS AND GROUND TRACKING Power supply and clock distribution are the most critical parts of any board layout. Because of this, it is advisable that these be completed before any other tracking is undertaken. After these, supply decoupling, and analog and high speed digital signals should be addressed. Track widths for all signals, especially power rails should be kept as wide as possible in order to reduce inductance. The Power and Ground planes themselves can form a useful capacitor. Flood filling for either or both of these supply rails, therefore, should be used where possible. It is important to ensure that there are no floating copper areas remaining on the board: all such areas should be connected to the ground plane. The flood filling should be done on the outside layers of the board. 8.3.3 POWER SUPPLY DECOUPLING Decoupling capacitor should be fitted as specified in Section 2.2 "Schematic Notes". The decoupling capacitors must be placed as close as possible to the pin being decoupled. The traces from these capacitors to the respective device pins should be wide and take a straight route. They should be routed over a ground plane as much as possible. The capacitor ground pins should also be connected directly to a ground plane. Surface mounting capacitors are preferred over wire-leaded types due to their lower ESR and ESL. It is often possible to fit these decoupling capacitors underneath and on the opposite side of the PCB to the digital ICs. This will provide the shortest tracking, and most effective decoupling possible. Refer to the application note Selecting Decoupling Capacitors for Atmel PLDs (doc0484.pdf) for further general information on decoupling capacitors. 8.3.4 VOLTAGE PUMP The voltage pump capacitors between EXTCAP0 and EXTCAP1 (Cd on the schematic in Section 2.0 "Schematics") must be placed as close as possible to the EXTCAPn pins. The two traces must be kept as short and as wide as possible for best pump performance. They should also be routed as parallel and as close as possible to each other in order to reduce emissions. 2019 Microchip Technology Inc. DS40001922C-page 29 MXT336U 1.0 8.4 Voltage Regulators Each supply rail requires a Low Drop-Out (LDO) voltage regulator, although an LDO can be shared where supply rails share the same voltage level. Figure 8-1 shows an example circuit for an LDO. FIGURE 8-1: EXAMPLE LDO CIRCUIT SUPPLY FROM HOST SUPPLY TO MAXTOUCH DEVICE VIN VOUT SENSE/ADI GND SHDN GND GND BYP GND An LDO regulator should be chosen that provides adequate output capability, low noise, good load regulation and step response. The voltage regulators listed in Table 8-1 have been tested and found to work well with maXTouch devices. If it is desired to use an alternative LDO, however, certain performance criteria should be verified before using the device. These are: * Stable with high value multi-layer ceramic capacitors on the output * Low output noise - less than 100 V RMS over the range 10 Hz to 1 MHz * Good load transient response - this should be less than 35 mV peak when a load step change of 100 mA is applied at the device output terminal . TABLE 8-1: Manufacturer Device Current Rating (mA) Microchip Technology Inc. MCP1824 300 Microchip Technology Inc. MCP1824S 300 Microchip Technology Inc. MAQ5300 300 Microchip Technology Inc. MCP1725 500 Microchip Technology Inc. MIC5323 300 Analog Devices ADP122/ADP123 300 Diodes Inc. AP2125 300 Diodes Inc. AP7335 300 Linear Technology LT1763CS8-3.3 500 NXP LD6836 300 Texas Instruments LP3981 300 Note: 8.4.1 SUITABLE LDO REGULATORS Some manufacturers claim that minimal or no capacitance is required for correct regulator operation. However, in all cases, a minimum of a 1.0 F ceramic, low ESR capacitor at the input and output of these devices should be used. The manufacturer's datasheets should always be referred to when selecting capacitors for these devices and the typical recommended values, types and dielectrics adhered to. SINGLE SUPPLY OPERATION When designing a PCB for an application using a single LDO, extra care should be taken to ensure short, low inductance traces between the supply and the touch controller supply input pins. Ideally, tracking for the individual supplies should be arranged in a star configuration, with the LDO at the junction of the star. This will ensure that supply current variations or noise in one supply rail will have minimum effect on the other supplies. In applications where a ground plane is not practical, this same star layout should also apply to the power supply ground returns. DS40001922C-page 30 2019 Microchip Technology Inc. MXT336U 1.0 Only regulators with a 300 mA or greater rating can be used in a single-supply design. Refer to the following application note for more information on routing with a single LDO: * Application Note: MXTAN0208 - Design Guide for PCB Layouts for Atmel Touch Controllers 8.4.2 MULTIPLE VOLTAGE REGULATOR SUPPLY The AVdd supply stability is critical for the device because this supply interacts directly with the analog front end. If noise problems exist when using a single LDO regulator, Microchip recommends that AVdd is supplied by a regulator that is separate from the digital supply. This reduces the amount of noise injected into the sensitive, low signal level parts of the design. 8.5 I2C Line Pull-up Resistors The values for pull-up resistors on SDA and SCL need to be chosen to ensure rise times are within I2C specification. If the rise time is too long the overall clock rate will be reduced. 8.6 Analog I/O In general, tracking for the analog I/O signals from the device should be kept as short as possible. These normally go to a connector which interfaces directly to the touchscreen. Ensure that adequate ground-planes are used. An analog ground plane should be used in addition to a digital one. Care should be taken to ensure that both ground planes are kept separate and are connected together only at the point of entry for the power to the PCB. This is usually at the input connector. 8.7 Component Placement and Tracking It is important to orient all devices so that the tracking for important signals (such as power and clocks) are kept as short as possible. 8.7.1 DIGITAL SIGNALS In general, when tracking digital signals, it is advisable to avoid sharp directional changes on sensitive signal tracks (such as analog I/O) and any clock or crystal tracking. A good ground return path for all signals should be provided, where possible, to ensure that there are no discontinuities. 8.7.2 QFN PACKAGE RESTRICTIONS The central pad on the underside of the QFN device should be connected to ground. Do not run any tracks underneath the body of the device, only ground. Figure 8-2 shows examples of good and bad tracking. FIGURE 8-2: EXAMPLES OF GOOD AND BAD TRACKING Note: The number of pins and their functions is shown for example purposes only and may not reflect the actual number or function on the device. Good Tracking 2019 Microchip Technology Inc. Bad Tracking DS40001922C-page 31 MXT336U 1.0 8.8 EMC and Other Observations The following recommendations are not mandatory, but may help in situations where particularly difficult EMC or other problems are present: * Try to keep as many signals as possible on the inside layers of the board. If suitable ground flood fills are used on the top and bottom layers, these will provide a good level of screening for noisy signals, both into and out of the PCB. * Ensure that the on-board regulators have sufficient tracking around and underneath the devices to act as a heatsink. This heatsink will normally be connected to the 0 V or ground supply pin. Increasing the width of the copper tracking to any of the device pins will aid in removing heat. There should be no solder mask over the copper track underneath the body of the regulators. * Ensure that the decoupling capacitors, especially high capacity ceramic type, have the requisite low ESR, ESL and good stability/temperature properties. Refer to the regulator manufacturer's datasheet for more information. DS40001922C-page 32 2019 Microchip Technology Inc. MXT336U 1.0 9.0 GETTING STARTED WITH MXT336U 9.1 Establishing Contact 9.1.1 COMMUNICATION WITH THE HOST The host can use the following interface to communicate with the device: * I2C interface (see Section 7.0 "I2C Communications") 9.1.2 POWER-UP SEQUENCE On power-up, the CHG line goes low to indicate that there is new data to be read from the device. If the CHG line does not go low, there is a problem with the device. The host should attempt to read any available messages to establish that the device is present and running following power-up or a reset. Examples of messages include reset or calibration messages. The host should also check that there is no configuration error reported. 9.2 Using the Object Protocol The device has an object-based protocol that is used to communicate with the device. Typical communication includes configuring the device, sending commands to the device, and receiving messages from the device. The host must perform the following initialization so that it can communicate with the device: 1. 2. 9.2.1 Read the start positions of all the objects in the device from the Object Table and build up a list of these addresses. Use the Object Table to calculate the report IDs so that messages from the device can be correctly interpreted. CLASSES OF OBJECTS The mXT336U contains the following classes of objects: * * * * * 9.2.2 Debug objects - provide a raw data output method for development and testing. General objects - required for global configuration, transmitting messages and receiving commands. Touch objects - operate on measured signals from the touch sensor and report touch data. Signal processing objects - process data from other objects (typically signal filtering operations). Support objects - provide additional functionality on the device. OBJECT INSTANCES TABLE 9-1: OBJECTS ON THE MXT336U Object Description Number of Instances Usage Debug Objects Diagnostic Debug T37 Allows access to diagnostic debug data to aid development. 1 Debug commands only. No configuration/tuning necessary. Not for use in production. Message Processor T5 Handles the transmission of messages. This object holds a message in its memory space for the host to read. 1 No configuration necessary. Command Processor T6 Performs a command when written to. Commands include reset, calibrate and backup settings. 1 No configuration necessary. Power Configuration T7 Controls the sleep mode of the device. Power consumption can be lowered by controlling the acquisition frequency and the sleep time between acquisitions. 1 Must be configured before use. Acquisition Configuration T8 Controls how the device takes each capacitive measurement. 1 Must be configured before use. General Objects 2019 Microchip Technology Inc. DS40001922C-page 33 MXT336U 1.0 TABLE 9-1: OBJECTS ON THE MXT336U (CONTINUED) Object Description Number of Instances Usage Touch Objects Key Array T15 Creates a rectangular array of keys. A Key Array T15 object reports simple on/off touch information. 1 Enable and configure as required. Multiple Touch Touchscreen T100 Creates a Touchscreen that supports the tracking of more than one touch. 1 Enable and configure as required. Grip Suppression T40 Suppresses false detections caused, for example, by the user gripping the edge of the touchscreen. 1 Enable and configure as required. Touch Suppression T42 Suppresses false detections caused, for example, by the user placing their face too near the touchscreen on a mobile phone. 1 Enable and configure as required. Passive Stylus T47 Processes passive stylus input. 1 Enable and configure as required. Shieldless T56 Allows a sensor to use true single-layer co-planar construction. 1 Enable and configure as required. Lens Bending T65 Compensates for lens deformation (lens bending) by attempting to eliminate the disturbance signal from the reported deltas. 3 Enable and configure as required. Noise Suppression T72 Performs various noise reduction techniques during touchscreen signal acquisition. 1 Enable and configure as required. Glove Detection T78 Allows for the reporting of glove touches. 1 Enable and configure as required. Retransmission Compensation T80 Limits the negative effects on touch signals caused by poor device coupling to ground. 1 Enable and configure as required. Unlock Gesture T81 Sends a message when a gesture satisfies the configuration settings for use in wake up or unlock situations. 4 Enable and configure as required. Touch Sequence Processor T93 Captures a sequence of touch and release locations to allow double taps to be detected. 1 Enable and configure as required. Self Capacitance Noise Suppression T108 Suppresses the effects of external noise within the context of self capacitance touch measurements. 1 Enable and configure as required. Symbol Gesture Processor T115 Detects arbitrary shaped gestures as a series of ordinal strokes. These are typically symbols drawn by the user for interpretation by the host as wake-up gestures or other application triggers. 1 Enable and configure as required. Sensor Correction T121 Allows adjustments to be made to mutual measurements from an associated touchscreen sensor. 1 Enable and configure as required. Communications Configuration T18 Configures additional communications behavior for the device. 1 Check and configure as necessary. Self Test T25 Configures and performs self-test routines to find faults on a touch sensor. 1 Configure as required for pin test commands. User Data T38 Provides a data storage area for user data. 1 Configure as required. Message Count T44 Provides a count of pending messages. 1 Read-only object. Signal Processing Objects Support Objects DS40001922C-page 34 2019 Microchip Technology Inc. MXT336U 1.0 TABLE 9-1: OBJECTS ON THE MXT336U (CONTINUED) Object 9.2.3 Description Number of Instances Usage CTE Configuration T46 Controls the capacitive touch engine for the device. 1 Must be configured. Timer T61 Provides control of a timer. 6 Enable and configure as required. Serial Data Command T68 Provides an interface for the host driver to deliver various data sets to the device. 1 Enable and configure as required. Dynamic Configuration Controller T70 Allows rules to be defined that respond to system events. 20 Enable and configure as required. Dynamic Configuration Container T71 Allows the storage of user configuration on the device that can be selected in run-time based on rules defined in the Dynamic Configuration Controller T70 object. 1 Configure if Dynamic Configuration Controller T70 is in use. CTE Scan Configuration T77 Configures enhanced X line scanning features. 1 Enable and configure as required. Auxiliary Touch Configuration T104 Allows the setting of self capacitance gain and thresholds for a particular measurement to generate auxiliary touch data for use by other objects. 1 Enable and configure if using self capacitance measurements Self Capacitance Global Configuration T109 Provides configuration for a self capacitance measurements employed on the device. 1 Check and configure as required (if using self capacitance measurements). Self Capacitance Tuning Parameters T110 Provides configuration space for a generic set of settings for self capacitance measurements. 4 Use under the guidance of Microchip field engineers only. Self Capacitance Configuration T111 Provides configuration for self capacitance measurements employed on the device. 2 Check and configure as required (if using self capacitance measurements). Self Capacitance Measurement Configuration T113 Configures self capacitance measurements to generate data for use by other objects. 1 Enable and configure as required. Symbol Gesture Configuration T116 Stores configuration data that defines the symbols to be detected by the Symbol Gesture Processor T115 object. 1 Configure if Symbol Gesture Processor T115 is in use. CONFIGURING AND TUNING THE DEVICE The objects are designed such that a default value of zero in their fields is a "safe" value that typically disables functionality. The objects must be configured before use and the settings written to the non-volatile memory using the Command Processor T6 object. Perform the following actions for each object: 1. 2. 3. 9.3 Enable the object, if the object requires it. Configure the fields in the object, as required. Enable reporting, if the object supports messages, to receive messages from the object. Writing to the Device The following mechanisms can be used to write to the device: * Using an I2C write operation (see Section 7.2 "Writing To the Device"). Communication with the device is achieved by writing to the appropriate object: * To send a command to the device, an appropriate command is written to the Command Processor T6 object. 2019 Microchip Technology Inc. DS40001922C-page 35 MXT336U 1.0 * To configure the device, a configuration parameter is written to the appropriate object. For example, writing to the Power Configuration T7 configures the power consumption for the device and writing to the touchscreen Multiple Touch Touchscreen T100 object sets up the touchscreen. Some objects are optional and need to be enabled before use. IMPORTANT! When the host issues any command within an object that results in a flash write to the device NonVolatile Memory (NVM), that object should have its CTRL RPTEN bit set to 1, if it has one (For example, from the following objects: Command Processor T6, Serial Data Command T68, Self Capacitance Global Configuration T109). This ensures that a message from the object writing to the NVM is generated at the completion of the process and an assertion of the CHG line is executed. The host must also ensure that the assertion of the CHG line refers to the expected object report ID before asserting the RESET line to perform a reset. Failure to follow this guidance may result in a corruption of device configuration area and the generation of a CFGERR. 9.4 Reading from the Device Status information is stored in the Message Processor T5 object. This object can be read to receive any status information from the device. The following mechanisms provide an interrupt-style interface for reading messages in the Message Processor T5 object: * The CHG line is asserted whenever a new message is available in the Message Processor T5 object (see Section 7.6 "CHG Line"). See Section 7.4 "Reading From the Device" for information on the format of the I2C read operation. Note that the host should always wait to be notified of messages. The host should not poll the device for messages. DS40001922C-page 36 2019 Microchip Technology Inc. MXT336U 1.0 10.0 DEBUGGING AND TUNING 10.1 SPI Debug Interface This interface is used for tuning and debugging when running the system and allows the development engineer to use Microchip maXTouch Studio to read the real-time raw data. This uses the low-level debug port, accessed via the SPI interface. The SPI Debug Interface consists of the DBG_SS, DBG_CLK, and DBG_DATA lines. It is recommended that these pins are routed to test points on all designs such that they can be connected to external hardware during system development. These lines should not be connected to power or GND. The SPI Debug Interface is enabled by the Command Processor T6 object and by default will be off. NOTE 10.2 The touch controller will take care of the pin configuration. When the DBG_SS, DBG_CLK, and DBG_DATA lines are in use for debugging, any alternative function for the pins cannot be used. Secondary Debug Interface This interface is used for low-level debugging when developing the system. The interface consists of the DBG2_CLK, DBG2_FRAME and DBG2_DATA0 to DBG2_DATA5 lines. These pins should be routed to test points on designs where a new sensor or display technology is being used, or if the design will use an active stylus. These lines should not be connected to power or GND. The touch controller will take care of the pin configuration. When these lines are in use, any alternative function for the pins cannot be used. The secondary interface is enabled by a special firmware build and by default will be off. 10.3 Object-based Protocol The device provides a mechanism for obtaining debug data for development and testing purposes by reading data from the Diagnostic Debug T37 object. Note that the Diagnostic Debug T37 is of most use for simple tuning purposes. When debugging a design, it is preferable to use the SPI Debug Interface, as this will have a much higher bandwidth and can provide real-time data. Note that the Diagnostic Debug T37 is of most use for simple tuning purposes. When debugging a design, it is preferable to use the SPI Debug Interface, as this will have a much higher bandwidth and can provide real-time data. 10.4 Self Test There is a Self Test T25 object that runs self-test routines in the device to find hardware faults on the sense lines and the electrodes. This object also performs an initial pin fault test on power-up to ensure that there is no X-to-Y short before the high-voltage supply is enabled inside the chip. A high-voltage short on the sense lines would break the device. 2019 Microchip Technology Inc. DS40001922C-page 37 MXT336U 1.0 11.0 SPECIFICATIONS 11.1 Absolute Maximum Specifications Vdd 3.6 V VddIO 3.6 V AVdd 3.6 V Voltage forced onto any pin -0.3 V to (Vdd, VddIO or AVdd) + 0.3 V Configuration parameters maximum writes 10,000 Maximum junction temperature 125C CAUTION! 11.2 11.2.1 11.2.1.1 Stresses beyond those listed under Absolute Maximum Specifications may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum specification conditions for extended periods may affect device reliability. Recommended Operating Conditions Operating temperature -40C to +85C Storage temperature -60C to +150C Vdd 3.3 V VddIO 1.8 V to 3.3 V AVdd 3.3 V XVdd with internal voltage doubler Vdd to 2 x Vdd Cx transverse load capacitance per node 0.6 pF to 3 pF Temperature slew rate 10C/min DC CHARACTERISTICS Analog Voltage Supply - AVdd Parameter Min Typ Max Units 3.0 3.3 3.47 V - - 0.036 V/s Notes AVdd Operating limits Supply Rise Rate DS40001922C-page 38 For example, for a 3.3 V rail, the voltage must not rise in less than 92 s 2019 Microchip Technology Inc. MXT336U 1.0 11.2.1.2 Digital Voltage Supply - Vdd, VddIO Parameter Min Typ Max Units Notes 1.71 3.3 3.47 V - - 0.036 V/s 2.7 3.3 3.47 V Supply Rise Rate - - 0.036 V/s For example, for a 3.3 V rail, the voltage must not rise in less than 92 s Supply Fall Rate - - 0.05 V/s For example, for a 3.3 V rail, the voltage must not fall in less than 66 s Min Typ Max Units Notes Vdd - 2 x Vdd V VddIO Operating limits Supply Rise Rate I2C For example, for a 3.3 V rail, the voltage must not rise in less than 92 s Vdd Operating limits 11.2.1.3 XVdd Voltage Supply - XVdd Parameter XVdd Operating limits 11.2.2 Maximum value with internal voltage doubler POWER SUPPLY RIPPLE AND NOISE Parameter Min Typ Max Units Vdd - - 50 mV Across frequency range 1 Hz to 1 MHz AVdd - - 40 mV Across frequency range 1 Hz to 1 MHz, with Noise Suppression enabled 2019 Microchip Technology Inc. Notes DS40001922C-page 39 MXT336U 1.0 11.3 Test Configuration The values listed below were used in the reference unit to validate the interfaces and derive the characterization data provided in the following sections. The values for the user application will depend on the circumstances of that particular project and will vary from those listed here. Further tuning will be required to achieve an optimal performance. TABLE 11-1: TEST CONFIGURATION Object/Parameter Description/Setting (Numbers in Decimal) Acquisition Configuration T8 CHRGTIME 34 MEASALLOW 11 MEASIDLEDEF 8 MEASACTVDEF 2 Key Array T15 Object Enabled XSIZE 1 YSIZE 3 CTE Configuration T46 IDLESYNCSPERX 16 ACTVSYNCSPERX 16 Shieldless T56 INTTIME Lens Bending T65 Instance 0 Object Enabled 25 Object Enabled Noise Suppression T72 Object Enabled Glove Detection T78 Object Enabled Retransmission Compensation T80 Object Enabled Multiple Touch Touchscreen T100 Object Enabled XSIZE 14 YSIZE 24 Auxiliary Touch Configuration T104 Object Enabled Self Capacitance Noise Suppression T108 Object Enabled Self Capacitance Configuration T111 Instance 0 INTTIME 60 IDLESYNCSPERL 24 ACTVSYNCSPERL 24 Self Capacitance Configuration T111 Instance 1 INTTIME 60 IDLESYNCSPERL 32 ACTVSYNCSPERL Self Capacitance Measurement Configuration T113 DS40001922C-page 40 32 Object Enabled 2019 Microchip Technology Inc. MXT336U 1.0 11.4 Supply Current 11.4.1 ANALOG SUPPLY Acquisition Rate (ms) 0 Touches (mA) 1 Touch (mA) 2 Touches (mA) 5 Touches (mA) Free-run 5.26 5.98 6.82 6.75 8 1.93 3.87 6.30 6.29 10 1.53 3.14 5.06 5.08 11 1.38 2.89 4.52 4.25 16 1.00 2.02 3.19 3.13 17 0.95 1.93 2.97 2.96 25 0.67 1.37 2.02 2.02 30 0.57 1.18 1.67 1.70 32 0.48 1.09 1.58 1.57 42 0.38 0.88 1.20 1.21 50 0.35 0.80 1.01 0.99 64 0.25 0.67 0.78 0.79 100 0.21 0.41 0.50 0.48 128 0.14 0.34 0.38 0.39 254 0.08 0.15 0.22 0.17 10.00 Current Consumption (mA) 9.00 8.00 7.00 6.00 5.00 0 Touches (mA) 4.00 1 Touch (mA) 3.00 2 Touches (mA) 2.00 5 Touches (mA) 1.00 0.00 Acquisition Rate (ms) 2019 Microchip Technology Inc. DS40001922C-page 41 MXT336U 1.0 11.4.2 DIGITAL SUPPLY 11.4.2.1 Vdd Acquisition Rate (ms) 0 Touches (mA) 1 Touch (mA) 2 Touches (mA) 5 Touches (mA) Free-run 5.18 5.71 6.01 7.35 8 1.96 3.74 5.94 7.09 10 1.61 3.04 4.54 5.54 11 1.50 2.57 4.11 4.99 16 1.01 1.94 2.85 3.46 17 0.98 1.88 2.69 3.16 25 0.65 1.29 1.83 2.19 30 0.58 1.12 1.52 1.88 32 0.55 1.06 1.42 1.74 42 0.42 0.86 1.06 1.28 50 0.35 0.74 0.91 1.11 64 0.28 0.66 0.74 0.89 100 0.16 0.46 0.46 0.53 128 0.20 0.39 0.38 0.50 254 0.12 0.18 0.19 0.25 10.00 Current Consumption (mA) 9.00 8.00 7.00 6.00 5.00 0 Touches (mA) 4.00 1 Touch (mA) 3.00 2 Touches (mA) 2.00 5 Touches (mA) 1.00 0.00 Acquisition Rate (ms) DS40001922C-page 42 2019 Microchip Technology Inc. MXT336U 1.0 11.4.2.2 VddIO Acquisition Rate (ms) 0 Touches (mA) 1 Touch (mA) 2 Touches (mA) 5 Touches (mA) Free-run 0.01 3.25 3.25 3.25 8 0.01 3.25 3.25 3.25 10 0.01 3.25 3.25 3.25 11 0.01 3.25 3.25 3.25 16 0.01 3.25 3.25 3.25 17 0.01 3.25 3.25 3.25 25 0.01 3.25 3.25 3.25 30 0.01 3.25 3.25 3.25 32 0.01 3.25 3.25 3.25 42 0.01 3.25 3.25 3.25 50 0.01 3.25 3.25 3.25 64 0.01 3.25 3.25 3.25 100 0.01 3.25 3.25 3.25 128 0.01 3.25 3.25 3.25 254 0.01 3.25 3.25 3.25 4.00 Current Consumption (mA) 3.50 3.00 2.50 2.00 0 Touches (mA) 1 Touch (mA) 1.50 2 Touches (mA) 1.00 5 Touches (mA) 0.50 0.00 Acquisition Rate (ms) 11.5 Deep Sleep Current TA = 25C Parameter Min Typ Max Units Notes Deep Sleep Current - 15 - A Vdd = 3.3 V, AVdd = 3.3 V Deep Sleep Power - 49 - W Vdd = 3.3 V, AVdd = 3.3 V 2019 Microchip Technology Inc. DS40001922C-page 43 MXT336U 1.0 11.6 11.6.1 Timing Specifications TOUCH LATENCY 25 Average Latency (ms) 20 15 10 T7 = Free run, pipelining ON 5 T7 = Free run, pipelining OFF 0 1 11.6.2 2 T100 TCHDIDOWN 3 SPEED 250 Pipelining ON (active mode) Pipelining OFF (active mode) Refresh Rate (Hz) 200 150 100 50 0 1 2 3 4 5 Number of Moving Touches DS40001922C-page 44 2019 Microchip Technology Inc. MXT336U 1.0 11.6.3 RESET TIMINGS Parameter Min Typ Max Units - 35 - ms Power on to CHG line low Hardware reset to CHG line low - 38 - ms Software reset to CHG line low - 55 - ms Note 1: 11.7 Vdd supply for POR VddIO supply for external reset Any CHG line activity before the power-on or reset period has expired should be ignored by the host. Operation of this signal cannot be guaranteed before the power-on/reset periods have expired. Touchscreen Sensor Characteristics Parameter Description Cm Mutual capacitance Typical value is between 0.15 pF and 10 pF on a single node. Cpx Mutual capacitance load to X Microchip recommends a maximum load of 300 pF on each X or Y line. (1) Cpy Mutual capacitance load to Y Cpx Self capacitance load to X Cpy Self capacitance load to Y Cpx Microchip recommends a maximum load of 100 pF on each X or Y line. (1) Self capacitance imbalance on X Cpy Note 1: 11.8 Notes Nominal value is 9.7 pF. Value increases by 1 pF for every 20 pF reduction in Cpx/Cpy (based on 100 pF load) Self capacitance imbalance on Y Please contact your Microchip representative for advice if you intend to use higher values. Input/Output Characteristics Parameter Description Min Typ Max Units Notes Vil Low input logic level -0.3 - 0.3 x VddIO V VddIO = 1.8 V to Vdd Vih High input logic level 0.7 x VddIO - VddIO V VddIO = 1.8 V to Vdd 9 10 16 k Input (RESET) RESET pin Internal pull-up resistor Input (SYNC, SDA, SCL, CHG) Vil Low input logic level -0.3 - 0.3 x VddIO V VddIO = 1.8 V to Vdd Vih High input logic level 0.7 x VddIO - VddIO V VddIO = 1.8 V to Vdd Iil Input leakage current - - 1 A Output (SCAN_OUT, DBG_CLK, DBG_DATA) Vol Low output voltage 0 - 0.2 x VddIO V VddIO = 1.8 V to Vdd Iol = max 0.4 mA Voh High output voltage 0.8 x VddIO - VddIO V VddIO = 1.8 V to Vdd Ioh = 0.4 mA 2019 Microchip Technology Inc. DS40001922C-page 45 MXT336U 1.0 11.9 I2C Specification Parameter Value Addresses 0x4A I2C specification Revision 6.0 Maximum bus speed (SCL) (1) 400 kHz Standard mode (2) 100 kHz mode (2) 400 kHz Fast Note 1: 2: The values of pull-up resistors should be chosen to ensure SCL and SDA rise and fall times meet the I2C specification. The value required will depend on the amount of capacitance loading on the lines. In systems with heavily laden I2C lines, even with minimum pull-up resistor values, bus speed may be limited by capacitive loading to less than the theoretical maximum. More detailed information on I2C operation is available from www.nxp.com/documents/user_manual/UM10204.pdf. 11.10 Touch Accuracy and Repeatability 1 Parameter Min Typ Max Units Notes Linearity (touch only; 5.4 mm electrode pitch) - 1 - mm 8 mm or greater finger Linearity (touch only; 4.2 mm electrode pitch) - 0.5 - mm 4 mm or greater finger Accuracy - 1 - mm Accuracy at edge - 2 - mm Repeatability - 0.25 - % X axis with 12-bit resolution 11.11 Thermal Packaging 11.11.1 THERMAL DATA Parameter 11.11.2 Description Typ Unit Condition Package JA Junction to ambient thermal resistance 33.7 C/W Still air 56-pin XQFN 6 x 6 x 0.4 mm JC Junction to case thermal resistance 10.1 C/W 56-pin XQFN 6 x 6 x 0.4 mm JUNCTION TEMPERATURE The maximum junction temperature allowed on this device is 125C. The average junction temperature in C (TJ) for this device can be obtained from the following: T J = T A + P D JA If a cooling device is required, use this equation: T J = T A + P D HEATSINK + JC where: * * * * * JA= package thermal resistance, Junction to ambient (C/W) (see Table 11.11.1) JC = package thermal resistance, Junction to case thermal resistance (C/W) (see Table 11.11.1) HEATSINK = cooling device thermal resistance (C/W), provided in the cooling device datasheet PD = device power consumption (W) TA is the ambient temperature (C) DS40001922C-page 46 2019 Microchip Technology Inc. MXT336U 1.0 11.12 ESD Information Parameter Value Reference standard Human Body Model (HBM) 2000 V JEDEC JS-001 Charge Device Model (CDM) 250 V JEDEC JS-001 11.13 Soldering Profile Profile Feature Green Package Average Ramp-up Rate (217C to Peak) 3C/s max Preheat Temperature 175C 25C 150 - 200C Time Maintained Above 217C 60 - 150 s Time within 5C of Actual Peak Temperature 30 s Peak Temperature Range 260C Ramp down Rate 6C/s max Time 25C to Peak Temperature 8 minutes max 11.14 Moisture Sensitivity Level (MSL) MSL Rating MSL3 2019 Microchip Technology Inc. Package Type(s) Peak Body Temperature Specifications XQFN 260oC IPC/JEDEC J-STD-020 DS40001922C-page 47 MXT336U 1.0 12.0 PACKAGING INFORMATION 12.1 Package Marking Information 12.1.1 56-PIN XQFN Pin 1 ID Abbreviation of Part Number MXT336U Date (year and week) Lot Code (variable text) 12.1.2 YYWW # CC LOTCODE Die Revision (variable text) Country Code (variable text) ORDERABLE PART NUMBERS The product identification system for maXTouch devices is described in "Product Identification System". That section also lists example part numbers for the mXT336U device. DS40001922C-page 48 2019 Microchip Technology Inc. MXT336U 1.0 12.2 Package Details The following section gives the technical details of the package for the device. 12.2.1 56-PIN XQFN 6 x 6 x 0.4 MM 2019 Microchip Technology Inc. DS40001922C-page 49 MXT336U 1.0 APPENDIX A: NOTE ASSOCIATED DOCUMENTS Some of the documents listed below are available under NDA only. The following documents are available by contacting Microchip HMID Division: Product Documentation * Application Note: MXTAN0213 - Interfacing with Atmel maXTouch Controllers Touchscreen design and PCB/FPCB layout guidelines * * * * Application Note: QTAN0054 - Getting Started with maXTouch Touchscreen Designs Application Note: MXTAN0208 - Design Guide for PCB Layouts for Atmel Touch Controllers Application Note: QTAN0080 - Touchscreens Sensor Design Guide Application Note: doc0484 - Selecting Decoupling Capacitors for Atmel PLDs Configuring the device * Application Note: QTAN0059 - Using the maXTouch Self Test Feature * Application Note: MXT0202 - Using the Unlock Gesture T81 Object Miscellaneous * Application Note: QTAN0050 - Using the maXTouch Debug Port * Application Note: QTAN0058 - Rejecting Unintentional Touches with the maXTouch Touchscreen Controllers * Application Note: QTAN0061 - maXTouch Sensitivity Effects for Mobile Devices Tools * maXTouch Studio User Guide (distributed as on-line help with maXTouch Studio) DS40001922C-page 50 2019 Microchip Technology Inc. MXT336U 1.0 APPENDIX B: REVISION HISTORY Revision CX (December 2015) Last released edition for firmware revision 1.0 - Atmel Release version Revision A (June 2017) Reformatted edition for firmware revision 1.0 - Microchip Release version This revision incorporates the following updates: * Updated to Microchip datasheet format: - "Connection and Configuration Information" moved to start of datasheet - "To Our Valued Customers" added - Section 12.0 "Packaging Information" updated with new headings. Part numbers moved to "Product Identification System" - Associated Documents moved to Appendix A "Associated Documents" - Revision History moved to this appendix - Index added - "Product Identification System" added - "The Microchip Web Site", "Customer Change Notification Service" and "Customer Support" sections added - Back cover updated * Features: Typical screen size updated * "Connection and Configuration Information": - Updated to show power rail information * Section 2.0 "Schematics": - Pull-ups are shown connected to the correct power rail (Vdd or VddIO) - Section 3.3.4 RESET Line removed; Creset no longer considered optional so note no longer needed * Section 4.0 "Sensor Layout": - Touch panel layout notes updated to aid clarity - Section 4.1 "Screen Size" added * Section 11.0 "Specifications": - DC characteristics updated to show rise/fall rates correctly. AVdd minimum is now 3.0 V - I/O characteristics updated to show power rail information * DBG_DAT pin renamed to DBG_DATA * References to restricted documents removed throughout * References to Atmel Corporation removed or changed to Microchip Technology Inc, where appropriate * New documentation number assigned Revision B (May 2018) This revision incorporates the following updates: * Features: - Front Panel Material updated - Touch Performance: Glove Support updated * Section 6.0 "Detailed Operation": - Section 6.4 "Sensor Acquisition": Section updated * Section 4.0 "Sensor Layout": - Tables showing allowable configurations added 2019 Microchip Technology Inc. DS40001922C-page 51 MXT336U 1.0 Revision C (April 2019) This revision incorporates the following updates: * Section 2.0 "Schematics": GND symbol added to VDDCORE on schematic diagram * Section 4.0 "Sensor Layout": Allowable touchscreen configurations updated * Section 11.7 "Touchscreen Sensor Characteristics" added DS40001922C-page 52 2019 Microchip Technology Inc. MXT336U 1.0 INDEX A J Absolute maximum specifications ............................................... 38 Adjacent key suppression technology......................................... 22 AKS. See Adjacent key suppression Analog voltage supply ................................................................. 38 AVdd voltage supply ................................................................... 38 Junction temperature ...................................................................46 C Microchip Internet Web Site.........................................................56 Moisture sensitivity level (msl) .....................................................47 Multiple function pins ...................................................................10 Mutual capacitance measurements ...............................................8 Calibration ................................................................................... 20 Capacitive Touch Engine (CTE).................................................... 8 Charge time................................................................................. 20 Checksum in I2C writes............................................................... 23 CHG line I2C ....................................................................................... 26 mode 0 operation ................................................................ 27 mode 1 operation ................................................................ 27 Clock stretching........................................................................... 28 Connection Information see Pinouts ............................................. 3 Customer Change Notification Service ....................................... 56 Customer Notification Service..................................................... 56 Customer Support ....................................................................... 56 D DC characteristics ....................................................................... 38 Debugging................................................................................... 37 object-based protocol.......................................................... 37 primary hardware interface ................................................. 11 secondary debug interface.................................................. 37 self test................................................................................ 37 SPI Debug Interface............................................................ 37 Detailed operation ....................................................................... 20 Detection integrator..................................................................... 20 Device overview ................................................................................ 8 Digital filtering.............................................................................. 21 Digital voltage supply .................................................................. 39 Direct Memory Access ................................................................ 24 E ESD information .......................................................................... 47 G Generic key array........................................................................ 16 Glove detection ........................................................................... 22 Grip suppression ......................................................................... 21 I I2C communications .............................................................. 23-28 CHG line.............................................................................. 26 clock stretching ................................................................... 28 reading from the device....................................................... 24 reading messages with DMA .............................................. 24 SCL line............................................................................... 27 SDA line .............................................................................. 27 specification ........................................................................ 46 writes in checksum mode.................................................... 23 writing to the device ............................................................ 23 I2C interface SCL line......................................................................... 10, 27 SDA line ........................................................................ 10, 27 Input/Output characteristics ........................................................ 45 Internal voltage pump.................................................................. 10 Internet Address.......................................................................... 56 2019 Microchip Technology Inc. L Lens bending ...............................................................................21 M N Noise suppression .......................................................................21 display .................................................................................21 O Object-based protocol..................................................................37 Operational modes ......................................................................20 Overview of the mXT336U.............................................................8 P Pinouts...........................................................................................3 Power supply ripple and noise.....................................................39 Primary debug interface...............................................................11 R Recommended operating conditions ...........................................38 Repeatability ................................................................................46 Reset timings ..............................................................................45 Retransmission compensation.....................................................21 S SCL line .......................................................................................27 SCLline ..................................................................................10, 27 Screen size ..................................................................................14 SDA line.................................................................................10, 27 Secondary debug interface..........................................................37 Self capacitance measurements....................................................8 Self test........................................................................................37 Sensor acquisition .......................................................................20 Sensor layout.........................................................................13-16 Shieldless support .......................................................................21 Soldering profile...........................................................................47 Specifications.........................................................................38-47 absolute maximum specifications ........................................38 analog voltage supply ..........................................................38 DC characteristics ...............................................................38 digital voltage supply ...........................................................39 esd information ....................................................................47 I2C specification...................................................................46 input/output characteristics ..................................................45 junction temperature............................................................46 moisture sensitivity level (msl) .............................................47 power supply ripple and noise .............................................39 recommended operating conditions ....................................38 repeatability .........................................................................46 reset timings .......................................................................45 soldering profile ...................................................................47 test configuration .................................................................40 thermal data.........................................................................46 timing specifications ............................................................44 touch accuracy ....................................................................46 touchscreen sensor characteristics .....................................45 DS40001922C-page 53 MXT336U 1.0 XVdd voltage supply ........................................................... 39 SPI Debug Interface.................................................................... 37 Standard Key arrays ................................................................... 14 Stylus support ............................................................................. 22 T Test configuration specification................................................... 40 Thermal data ............................................................................... 46 Timing specifications................................................................... 44 Touch accuracy........................................................................... 46 Touch detection....................................................................... 8, 20 Touchscreen sensor characteristics............................................ 45 Tuning ......................................................................................... 37 U Unintentional touch suppression ................................................. 22 V Vdd voltage supply...................................................................... 39 VddCore supply........................................................................... 10 VddIO voltage supply .................................................................. 39 W WWW Address............................................................................ 56 X XVdd voltage supply ................................................................... 39 DS40001922C-page 54 2019 Microchip Technology Inc. MXT336U 1.0 PRODUCT IDENTIFICATION SYSTEM The table below gives details on the product identification system for maXTouch devices. See "Orderable Part Numbers" below for example part numbers for the mXT336U device. To order or obtain information, for example on pricing or delivery, refer to the factory or the listed sales office. PART NO. Device -XXX [X] Package Temperature Range [XX] [X] [XXX] Sample Type Tape and Reel Option Pattern Device: Base device name Package: A C2U MA5U = = = QFP (Plastic Quad Flatpack) UFBGA (Ultra Thin Fine-pitch Ball Grid Array) QFN (Quad Flat No Lead Sawn) Temperature Range: Blank T B X = = = = -40C to +85C (Grade 3) -40C to +85C (Grade 3) -40C to +105C (Grade 2) 0C to +70C (Engineering Samples) Sample Type: Blank ES = = Release Sample Pre-release (Engineering) Sample Tape and Reel Option: Blank R = = Standard Packaging (Tube or Tray) Tape and Reel (1) Pattern: QTP, SQTP, Code or Special Requirements (Blank Otherwise) Note 1: Tape and Reel identifier only appears in the catalog part number description. This identifier is used for ordering purposes and is not printed on the device package. See "Orderable Part Numbers" below or check with your Microchip Sales Office for package availability with the Tape and Reel option. Orderable Part Numbers Orderable Part Number ATMXT336U-MAU021 (Supplied in trays) ATMXT336U-MAUR021 (Supplied in tape and reel) 2019 Microchip Technology Inc. Firmware Revision 1.0.AB Description 56-pin XQFN 6 x 6 x 0.4 mm RoHS compliant Industrial grade sample; not suitable for automotive characterization DS40001922C-page 55 MXT336U 1.0 THE MICROCHIP WEB SITE Microchip provides online support via our WWW site at www.microchip.com. This web site is used as a means to make files and information easily available to customers. Accessible by using your favorite Internet browser, the web site contains the following information: * Product Support - Data sheets and errata, application notes and sample programs, design resources, user's guides and hardware support documents, latest software releases and archived software * General Technical Support - Frequently Asked Questions (FAQ), technical support requests, online discussion groups, Microchip consultant program member listing * Business of Microchip - Product selector and ordering guides, latest Microchip press releases, listing of seminars and events, listings of Microchip sales offices, distributors and factory representatives CUSTOMER CHANGE NOTIFICATION SERVICE Microchip's customer notification service helps keep customers current on Microchip products. Subscribers will receive e-mail notification whenever there are changes, updates, revisions or errata related to a specified product family or development tool of interest. To register, access the Microchip web site at www.microchip.com. Under "Support", click on "Customer Change Notification" and follow the registration instructions. CUSTOMER SUPPORT Users of Microchip products can receive assistance through several channels: * * * * Distributor or Representative Local Sales Office Field Application Engineer (FAE) Technical Support Customers should contact their distributor, representative or Field Application Engineer (FAE) for support. Local sales offices are also available to help customers. A listing of sales offices and locations is included in the back of this document. Technical support is available through the web site at: http://microchip.com/support DS40001922C-page 56 2019 Microchip Technology Inc. Note the following details of the code protection feature on Microchip devices: * Microchip products meet the specification contained in their particular Microchip Data Sheet. * Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. * There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip's Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property. * Microchip is willing to work with the customer who is concerned about the integrity of their code. * Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as "unbreakable." Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our products. Attempts to break Microchip's code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act. Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights unless otherwise stated. Microchip received ISO/TS-16949:2009 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California and India. The Company's quality system processes and procedures are for its PIC(R) MCUs and dsPIC(R) DSCs, KEELOQ(R) code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip's quality system for the design and manufacture of development systems is ISO 9001:2000 certified. QUALITY MANAGEMENT SYSTEM CERTIFIED BY DNV Trademarks The Microchip name and logo, the Microchip logo, AnyRate, AVR, AVR logo, AVR Freaks, BitCloud, chipKIT, chipKIT logo, CryptoMemory, CryptoRF, dsPIC, FlashFlex, flexPWR, Heldo, JukeBlox, KeeLoq, Kleer, LANCheck, LINK MD, maXStylus, maXTouch, MediaLB, megaAVR, MOST, MOST logo, MPLAB, OptoLyzer, PIC, picoPower, PICSTART, PIC32 logo, Prochip Designer, QTouch, SAM-BA, SpyNIC, SST, SST Logo, SuperFlash, tinyAVR, UNI/O, and XMEGA are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. ClockWorks, The Embedded Control Solutions Company, EtherSynch, Hyper Speed Control, HyperLight Load, IntelliMOS, mTouch, Precision Edge, and Quiet-Wire are registered trademarks of Microchip Technology Incorporated in the U.S.A. Adjacent Key Suppression, AKS, Analog-for-the-Digital Age, Any Capacitor, AnyIn, AnyOut, BodyCom, CodeGuard, CryptoAuthentication, CryptoAutomotive, CryptoCompanion, CryptoController, dsPICDEM, dsPICDEM.net, Dynamic Average Matching, DAM, ECAN, EtherGREEN, In-Circuit Serial Programming, ICSP, INICnet, Inter-Chip Connectivity, JitterBlocker, KleerNet, KleerNet logo, memBrain, Mindi, MiWi, motorBench, MPASM, MPF, MPLAB Certified logo, MPLIB, MPLINK, MultiTRAK, NetDetach, Omniscient Code Generation, PICDEM, PICDEM.net, PICkit, PICtail, PowerSmart, PureSilicon, QMatrix, REAL ICE, Ripple Blocker, SAM-ICE, Serial Quad I/O, SMART-I.S., SQI, SuperSwitcher, SuperSwitcher II, Total Endurance, TSHARC, USBCheck, VariSense, ViewSpan, WiperLock, Wireless DNA, and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. Silicon Storage Technology is a registered trademark of Microchip Technology Inc. in other countries. GestIC is a registered trademark of Microchip Technology Germany II GmbH & Co. KG, a subsidiary of Microchip Technology Inc., in other countries. All other trademarks mentioned herein are property of their respective companies. (c) 2017 - 2019, Microchip Technology Incorporated, All Rights Reserved. ISBN: 978-1-5224-4365-0 == ISO/TS 16949 == 2019 Microchip Technology Inc. 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