CPT007B-A02-GU - SILICON LABS

TouchXpress™ Family

CPT007B Data Sheet

The CPT007B device, part of the TouchXpress family, is designed

to quickly replace mechanical buttons with modern capacitive

touch buttons by eliminating firmware complexity and reducing de-

velopment time.

Supporting up to 7 capacitive sensor inputs in a 3 mm x 3 mm QFN package, the

CPT007B is a highly-integrated device that provides a simple solution for adding capaci-

tive touch. The device also comes with advanced features like moisture immunity, wake-

on proximity, and buzzer feedback for an enhanced user experience. No firmware devel-

opment is needed, and all the capacitive touch sense parameters can be configured us-

ing a simple GUI-based configurator. By eliminating the need for complex firmware de-

velopment, the CPT007B device enables rapid user interface designs with minimal de-

velopment effort.

The CPT007B device is ideal for a wide range of capacitive touch applications, including

the following:

KEY FEATURES

• No firmware development required

• Simple GUI-based configurator

• 7 Capacitive Sensor inputs with

programmable sensitivity

• 7 General purpose outputs (GPOs) to

communicate to the host processor or drive

LEDs

• Lowest power capacitive sense solution

• Active — 200 µA

• Sleep — 1 µA

• Wake on proximity

• Superior noise immunity: SNR up to 270:1

• Moisture immunity

• Mutually-exclusive touch qualifier

• Button touch time-out to avoid false

touches

• Buzzer output for audible touch feedback

• Home appliances

• Instrument / Control panels

• White goods

• Medical equipment

• Consumer electronics

• Lighting control

Output

Features

Configurable

Output Pin for

each Input

Capacitive Touch Sensing

Features

Input

Features

Lowest power mode with feature operational:

Input Engine

with

7 Inputs

Proximity Wake

Input

Baselining

Low Power State

Machine

Configuration

Profile for each

Input

Touch Time-Out

Timer

Touch

Qualification

Mutually-

Exclusive Touch

Qualifier

Optional Buzzer

Output

Optimized ActiveActive Low Power Sleep

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This information applies to a product under development. Its characteristics and specifications are subject to change without notice.

1. Feature List and Ordering Information

T–0 B A –R

Tape and Reel (Optional)

Package Type — QFN20 (M), QSOP24 (U)

Firmware Revision

Hardware Revision

Capacitive Sense Features — Button (B)

Interface Type — GPO (0), I2C (1)

Number of Capacitive Sense Inputs

CP G M

Temperature Grade — –40 to +85 °C (G)

Silicon Labs Xpress Product Line

TouchXpress Family

Figure 1.1. CPT007B Part Numbering

The CPT007B has the following features:

• Capacitive sensing input engine with 7 inputs

• Post-sample touch qualification engine

• Configuration profile space in non-volatile memory

• Pin output with configurable polarity and drive strength

• Low power state machine to minimize current draw in all use cases

• Capacitive proximity sensing input

• Buzzer output

• Mutually exclusive touch qualifier

• Touch time-out timer

Table 1.1. Product Selection Guide

Ordering

Part Number

Pb-free

(RoHS Compliant)

Temperature Range

Package

CPT007B-A02-GM Yes -40 to +85 °C QFN20

CPT007B-A02-GU Yes -40 to +85 °C QSOP24

CPT007B Data Sheet

Feature List and Ordering Information

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2. Typical Connection Diagrams

2.1 Signal, Analog, and Power Connections

Figure 2.1 Connection Diagram on page 2 shows a typical connection diagram for the power pins of CPT007B devices.

CPT007B

Device

4.7 µF and 0.1 µF

bypass capacitors

required for the power

pins placed as close to

the pins as possible.

1.8-3.6 V (in)

Host

Processor

...

1.8-3.6 V (in)

Electrode

...

GND

VDD

OUT00

OUT06

CS06

CS00

Config Data

Config Clk / RSTb

OUT01

Figure 2.1. Connection Diagram

CPT007B Data Sheet

Typical Connection Diagrams

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2.2 Configuration

The diagram below shows a typical connection diagram for the configuration connections pins. The ToolStick Base Adapter is available

on the evaluation board.

CPT007B Device

Config Clk

1 k

VDD

Config Data

GND

ToolStick

Figure 2.2. Configuration Connection Diagram

CPT007B Data Sheet

Typical Connection Diagrams

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3. Electrical Specifications

3.1 Electrical Characteristics

All electrical parameters in all tables are specified under the conditions listed in Table 3.1 Recommended Operating Conditions on page

4, unless stated otherwise.

3.1.1 Recommended Operating Conditions

Table 3.1. Recommended Operating Conditions

Parameter Symbol Test Condition Min Typ Max Unit

Operating Supply Voltage on VDD VDD 1.8 2.4 3.6 V

Minimum RAM Data Retention

Voltage on VDD1

VRAM Not in Sleep Mode — 1.4 — V

Sleep Mode — 0.3 0.5 V

Operating Ambient Temperature TA–40 — 85 °C

Note:

1. All voltages with respect to GND.

CPT007B Data Sheet

Electrical Specifications

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3.1.2 Power Consumption

See 3.4 Typical Performance Curves for power consumption plots.

Table 3.2. Power Consumption

Parameter Symbol Test Condition Min Typ Max Unit

Active Mode Supply Current IDD — 3.1 — mA

Optimized Active Mode Supply

Current

IDD — 180 — µA

Sleep Mode Current1, 2 IDD 3 sensors or fewer — 0.78 — µA

4 sensors — 0.79 — µA

5 sensors — 0.81 — µA

6 sensors — 0.82 — µA

7 sensors — 0.84 — µA

System Current with Varying Scan

Time — Base with One Sensor1

IDD Scan period = 10 ms — 154 — µA

Scan period = 20 ms — 77 — µA

Scan period = 50 ms — 31 — µA

Scan period = 75 ms — 21 — µA

Scan period = 100 ms — 16 — µA

System Current with Varying Scan

Time — Each Additional Sensor1

IDD Scan period = 10 ms — 47 — µA

Scan period = 20 ms — 23 — µA

Scan period = 50 ms — 9 — µA

Scan period = 75 ms — 6 — µA

Scan period = 100 ms — 5 — µA

Note:

1. Measured with Free Run Mode disabled and sensors set to 4x accumulation, 8x gain.

2. Measured with scan period set to 250 ms.

CPT007B Data Sheet

Electrical Specifications

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3.1.3 Reset and Supply Monitor

Table 3.3. Reset and Supply Monitor

Parameter Symbol Test Condition Min Typ Max Unit

VDD Supply Monitor Threshold VVDDM Reset Trigger 1.7 1.75 1.8 V

VWARN Early Warning 1.8 1.85 1.9 V

Power-On Reset (POR) Monitor

Threshold

VPOR Rising Voltage on VDD — 1.75 — V

Falling Voltage on VDD 0.75 1.0 1.3 V

VDD Ramp Time tRMP Time to VDD ≥ 1.8 V — — 3 ms

RST Low Time to Generate Reset tRSTL 15 — — µs

Boot Time1tboot 1 sensor — 25 — ms

2 sensors — 40 — ms

3 sensors — 55 — ms

4 sensors — 70 — ms

5 sensors — 85 — ms

6 sensors — 100 — ms

7 sensors — 115 — ms

Note:

1. Boot time is defined as the time from a power-on reset or /RST pin release until the first capacitive sense scan begins.

3.1.4 Configuration Memory

Table 3.4. Configuration Memory

Parameter Symbol Test Condition Min Typ Max Units

Endurance (Write/Erase Cycles) NWE 20 k 100 k — Cycles

Note:

1. Data Retention Information is published in the Quarterly Quality and Reliability Report.

CPT007B Data Sheet

Electrical Specifications

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3.1.5 Capacitive Sense

Table 3.5. Capacitive Sense

Parameter Symbol Test Condition Min Typ Max Unit

Scan Time Per Sensor1tSCAN Accumulation = 1x — 64 — µs

Accumulation = 4x — 256 — µs

Accumulation = 8x — 512 — µs

Accumulation = 16x — 1.024 — ms

Accumulation = 32x — 2.048 — ms

Accumulation = 64x — 4.096 — ms

Signal to Noise Ratio1, 2 SNR Accumulation = 1x — 90:1 — codes

Accumulation = 4x — 180:1 — codes

Accumulation = 8x — 182:1 — codes

Accumulation = 16x — 210:1 — codes

Accumulation = 32x — 230:1 — codes

Accumulation = 64x — 270:1 — codes

Conversion Time tCONV Gain = 1x — 205 — µs

Gain = 2x — 123 — µs

Gain = 3x — 98 — µs

Gain = 4x — 85 — µs

Gain = 5x — 76 — µs

Gain = 6x — 72 — µs

Gain = 7x — 67 — µs

Gain = 8x — 64 — µs

Total Processing Time3tPROC 1 sensor — 576 — µs

2 sensors — 796 — µs

3 sensors — 1.0 — ms

4 sensors — 1.2 — ms

5 sensors — 1.4 — ms

6 sensors — 1.7 — ms

7 sensors — 1.9 — ms

Maximum External Capacitive

Load

CEXTMAX Gain = 8x — 45 — pF

Gain = 1x — 500 — pF

Maximum External Series Impe-

dance

REXTMAX Gain = 8x — 50 — kΩ

CPT007B Data Sheet

Electrical Specifications

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Parameter Symbol Test Condition Min Typ Max Unit

Note:

1. Measured with gain set to 8x.

2. Measured with an evaluation board with 1/16" overlay using Capacitive Sense Profiler.

3. Sensors configured to 8x gain, 1x accumulation with sensor sampling and system processing time included and mutually-exclu-

sive buttons, buzzer, and touch time-outs disabled.

3.1.6 General Purpose and Buzzer Outputs

Table 3.6. General Purpose and Buzzer Outputs

Parameter Symbol Test Condition Min Typ Max Unit

Output High Voltage (High Drive) VOH IOH = –3 mA VDD – 0.7 — — V

Output Low Voltage (High Drive) VOL IOL = 8.5 mA — — 0.6 V

Output High Voltage (Low Drive) VOH IOH = –1 mA VDD – 0.7 — — V

Output Low Voltage (Low Drive) VOL IOL = 1.4 mA — — 0.6 V

Weak Pull-Up Current IPU VDD = 1.8 V

VIN = 0 V

— –4 — µA

VDD = 3.6 V

VIN = 0 V

–35 –20 — µA

3.2 Thermal Conditions

Table 3.7. Thermal Conditions

Parameter Symbol Test Condition Min Typ Max Unit

Thermal Resistance* θJA — 60 — °C/W

Note:

1. Thermal resistance assumes a multi-layer PCB with any exposed pad soldered to a PCB pad.

CPT007B Data Sheet

Electrical Specifications

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3.3 Absolute Maximum Ratings

Stresses above those listed in Table 3.8 Absolute Maximum Ratings on page 9 may cause permanent damage to the device. This is

a stress rating only and functional operation of the devices at those or any other conditions above those indicated in the operation list-

ings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. For

more information on the available quality and reliability data, see the Quality and Reliability Monitor Report at http://www.silabs.com/

support/quality/pages/default.aspx.

Table 3.8. Absolute Maximum Ratings

Parameter Symbol Test Condition Min Max Unit

Ambient Temperature Under Bias TBIAS –55 125 °C

Storage Temperature TSTG –65 150 °C

Voltage on VDD VDD GND–0.3 4.0 V

Voltage on I/O pins or RSTb VIN GND–0.3 VDD + 0.3 V

Total Current Sunk into Supply Pin IVDD — 400 mA

Total Current Sourced out of Ground

IGND 400 — mA

Current Sourced or Sunk by Any I/O

Pin or RSTb

IIO –100 100 mA

Maximum Total Current through all

Port Pins

IIOTOT — 200 mA

Operating Junction Temperature TJ–40 105 °C

Exposure to maximum rating conditions for extended periods may affect device reliability.

CPT007B Data Sheet

Electrical Specifications

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3.4 Typical Performance Curves

Figure 3.1. Active Mode Processing Time Per Sensor

Note: Active mode processing time per sensor measured with sensors configured to 1x accumulation, 8x gain. Sensor sampling and

system processing time is included with mutually-exclusive buttons, the buzzer, and touch time-outs disabled.

Figure 3.2. Current vs. Active Mode Scan Period — Base Current Consumption

CPT007B Data Sheet

Electrical Specifications

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Figure 3.3. Current vs. Active Mode Scan Period — Current Consumption for Each Additional Sensor

Note: Active mode scan period current draw measured with free run mode disabled and all 7 sensors enabled at 4x accumulation, 8x

gain. In addition, the buzzer and mutually-exclusive button groups were disabled.

Figure 3.4. Typical VOH Curves

CPT007B Data Sheet

Electrical Specifications

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Figure 3.5. Typical VOL Curves

CPT007B Data Sheet

Electrical Specifications

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4. Functional Description

4.1 Capacitive Sensing Input

4.1.1 Introduction

The capacitive to digital converter uses an iterative, charge-timing self-capacitance technique to measure capacitance on an input pin.

Sampling is configured and controlled by settings in the non-volatile configuration profile, which can be changed through the 2-pin con-

figuration interface.

Baseline

Active threshold

Touch delta Inactive threshold

Capacitance

Time

Figure 4.1. Capacitive Sense Data Types

4.1.2 Touch Qualification Criteria

The device detects a touch event when an inactive (untouched) input enabled by the input enable mask detects an sequence of meas-

urements that cross the active threshold.

The device detects a touch release event when an active (touched) input enabled by the input enable mask detects an sequence of

measurements that cross the inactive threshold.

The debounce configuration profile parameter defines how many measurements in a row must cross a threshold before a touch or re-

lease is qualified. In electrically noisy environments more heavily filtered data is used for qualification.

4.1.3 Thresholds

Capacitive sensing inputs use input-specific thresholds for touch qualification. Each input uses two thresholds, one to detect inactive-to-

active transitions on the input, and another to determine active-to-inactive transitions on the input. The inputs use two thresholds to add

hysteresis and prevent active/inactive ringing on inputs. Each threshold can be set through Simplicity Studio tools and all thresholds are

stored in non-volatile memory in the device's configuration profile.

Thresholds are defined as percentages of a capacitive sensing input's touch delta.

CPT007B Data Sheet

Functional Description

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4.1.4 Debounce Counter

Each capacitive sensing input maintains its own debounce counter. For an inactive sensor, this counter tracks the number of succes-

sive samples which have crossed that input's active threshold. For an active sensor, this counter tracks the number of successive sam-

ples which have crossed the inactive threshold. When the counter reaches a terminal value defined in the the configuration profile, the

touch/release event is qualified.

4.1.5 Touch Deltas

Each capacitive sensing input uses a stored touch delta value that describes the expected difference between inactive and active ca-

pacitive sensing output codes. This value is stored in the configuration profile for the system and is used by the touch qualification en-

gine, which defines inactive and active thresholds relative to the touch delta.

The touch deltas are stored in the configuration profile in a touch delta/16 format. For this reason, touch deltas must be configured as

multiples of 16.

4.1.6 Auto-Accumulation and Averaging

Capacitive sensing inputs have an auto-accumulate and average post-sample filter that can be used to improve signal strength if nee-

ded. Settings stored in the configuration profile can configure the engine to accumulate 1, 4, 8, 16, 32, or 64 samples. After the defined

number of samples have been accumulated, the result is divided by either 1, 4, 8, 16, 32, or 64, depending on the accumulation setting.

This auto-accumulated and averaged value is the sample output used for all touch qualification processing. Note that sample time per

sensor increases as the level of accumulation increases. To reduce current consumption, the engine should not be set to auto-accumu-

late unless it is required to achieve acceptable signal strength due to thick overlays or other system-level factors.

4.1.7 Drive strength

The drive strength of the current source used to charge the electrode being measured by the capacitive sensing input can be adjusted

in integer increments from 1x to 8x (8x is the default). High drive strength gives the best sensitivity and resolution for small capacitors,

such as those typically implemented as touch-sensitive PCB features. To measure larger capacitance values, the drive strength should

be lowered accordingly. The highest drive strength setting that yields capacitive sensing output which does not saturate the sensing

engine when the electrode is active (touched) should always be used to maximize input sensitivity.

4.1.8 Active Mode Scan Enable

Active mode scanning of capacitive sensing inputs is controlled by an enable setting for each capacitive sensing input. This setting is

stored in the configuration profile.

4.1.9 Active Mode Scan Period

The capacitive sensing input engine stays in active mode whenever one or more inputs have qualified as active. During this time, the

sensors scan at a periodicity defined by the active mode scan period, which is stored in the configuration profile. Every active mode

scan pushes new samples through the processing engine, which checks for new touch and release events on all enabled inputs.

If free run mode is enabled, the engine will repeatedly scan all enabled inputs during the active mode scan period. In this mode of

operation, the active mode scan period is used as a timer to determine how much time has passed since the last qualified active sensor

has been seen. When a defined amount of time without a qualified touch event has occurred, the engine switches to a low power mode

using the sleep mode scan period, and conserves current.

If free run mode is disabled, the engine will enter a low power state after completing one scan of all enabled inputs and processing the

resulting samples. The engine will remain in this low power state until it wakes, at a time defined by active mode scan period, to perform

another scan.

CPT007B Data Sheet

Functional Description

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4.1.10 Active Mode Scan Type

The active mode scan type, which is stored in the configuration profile, controls whether the capacitive sensing engine in active mode

will scan only once during the active mode scan period before going to sleep, or whether the engine will continue scanning as quickly

as possible during the active mode scan period, never entering a low power state.

For optimal responsiveness, the engine should be configured to run with free run mode enabled. Setting the scan mode to 'free run'

causes touch qualification on a new touch to occur as quickly as the scanning engine can convert and process samples on all sensors.

In this mode, qualification time is not bounded by active mode scan period, and is only bounded by scanning configuration factors such

as the debounce setting, the number of enabled sensors, the accumulation setting on each sensor, and the timing constraints of any

enabled component.

For optimal current draw when in active mode, the engine should be configured to use the 'one scan per period' mode setting. In this

case, touch qualification is bound by the scan period and the debounce setting of the device.

Touch Event

(t = 0 ms) 10 ms 20 ms 30 ms 40 ms

Optimized

Active sample sample

Active process additional

processing process additional

processing

Sleep sleep sleep

debounce

count = 1

touch

qualified

Figure 4.2. Timing and Current — One Sample Per Period Mode

Touch Event

(t = 0 ms) 10 ms 20 ms 30 ms 40 ms

Optimized

Active sample

Active process additional

processing

Sleep

debounce

count = 1

touch

qualified

sample

process additional

processing

Figure 4.3. Timing and Current — Free Run Mode

4.1.11 Sleep Mode Scan Period

The sleep mode scan period defines the rate at which a scan of the inputs enabled as wake-up sources are sampled. Each enabled

sensor can also be enabled as a wake-up source. After the sleep mode scan completes, the scan is processed for a qualified candidate

touch. If a candidate touch is qualified, the system wakes form sleep mode and enters active mode scanning.

The sleep mode scan period is stored in the configuration profile and is defined in units of ms.

CPT007B Data Sheet

Functional Description

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4.1.12 Active Mode and Sleep Mode Transitions

Capacitive sensing inputs will stay in active mode until no inputs detect qualified touches for a span of time defined by the counts until

sleep parameter stored in the configuration profile. The scan period of enabled inputs is defined by the active mode scan period, also

found in the configuration profile. If free run mode is enabled, the active mode sensing engine will remain awake and scanning the sen-

sors as fast as possible. If free run mode is disabled, the engine will put itself into a low power state for the remainder of the active

mode scan period, after a scan has completed.

When in sleep mode, the sensing engine will wake at a period defined by sleep mode scan period to do a scan on sensors that have

been enabled as wakeup sources. If the engine finds a candidate touch in this state, the system reverts to active mode to continue

scanning.

Note that in systems where a proximity input is selected, the sleep mode scan engine uses conversions on the proximity input instead

of sensors enabled as wakeup sources.

Devices configured to wake on a touch will attempt to qualify the candidate touch that initiated the sleep-to-active transition. If qualifica-

tion completes successfully, the device will signal this qualification to the external system. Touch qualification of this candidate touch

uses the same active mode thresholds, debounce setting, and active mode scan period settings as any touch that occurs during active

mode scanning.

qualified touch

release

Touch Delta

touch release new touch

Device Execution

no touch

counter = 1

no touch

counter = 2

...

no touch counter

= counts before

sleep

device enters

sleep

sleep scan sees

touch, wakes,

qualifies touch

no touch

counter = 0

Figure 4.4. Active and Sleep Transitions

4.2 Pin Output

4.2.1 Introduction

Results of the capacitive sensing touch qualification engine are communicated through a set of digital output pins. The state of each pin

is bound to the touch qualification status of one capacitive sensing input pin. If a capacitive sensing input has qualified an active event,

the corresponding output pin will be set to its active state. If the input has qualified a release event is inactive, the corresponding output

pin will be set to its inactive state. Pin polarity and drive strength are configurable parameters.

CPT007B Data Sheet

Functional Description

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4.2.2 Configuration

The configuration profile allows users to globally configure outputs as active high or active low. The configuration profile also allows

users to globally configure pins as open drain outputs or push-pull outputs.

4.3 Capacitive Proximity Sensing

4.3.1 Wake on Proximity

The wake on capacitive proximity detection engine monitors for the presence of a conductive object such as a hand to move within

detectable range of the sensor. When the engine detects an object, the device wakes from sleep and can begin qualifying touch events

on all sensors enabled for active mode sensing.

4.3.2 Proximity Sensing Output

Proximity sensing state is output using a designated Out pin on the CPT007B. By choosing this pin, the user is effectively disabling the

corresponding CS input pin. If the user is configuring proximity sensing to mode 2 operation, where a single capacitive sensing input pin

is used for proximity detection, it is recommended that this input pin be the pin that corresponds to the selected proximity Out pin.

4.3.3 Proximity Configuration

The proximity sensing feature uses a single sensor input for proximity qualification. The configuration profile stores the pin chosen by

the user. The sensor used for proximity qualification should also have a drive strength setting that is as high as possible without saturat-

ing the input when no conductive object is in proximity to the proximity sensor. The accumulation setting of the input is also configura-

ble.

The proximity threshold controls the sensitivity of the input. A lower threshold setting increases sensitivity and increases the range of

the sensor.

A proximity sensing input cannot be used for touch qualification, and so the active and inactive thresholds are not used for proximity

sensors. Additionally, the proximity input has no effect on other components of the device such as mutually exclusive button groups,

buzzer output, touch time out timers, and sliders.

4.4 Touch Time-Out

The touch time-out feature can be enabled and disabled through the configuration profile. When enabled, the device will monitor touch

event duration on each input independently.

When a touch event exceeds a duration specified in the configuration profile, the device forces a release event, even if the user is still

actively touching the sensor.

The feature qualifies a touch release by adding the configured touch delta value for that sensor to the sensor's current baseline value.

By doing this, the raw data-to-baseline delta created by the touch will be removed, and the touch qualification engine will see this as a

touch release event.

When the user removes a finger from a sensor that had been qualified active but has been qualified released through touch timeout, the

resulting raw-to-baseline negative delta will be aggressively tracked downward by the baseline, resulting in a sensor that remains sensi-

tive to successive touches.

The touch timeout duration is configured globally, so all inputs are monitored for the same touch duration.

If both the touch timeout feature and the mutually exclusive button group feature are enabled, the timeout timer will only run on the

touch that is externally reported as being active.

4.5 Buzzer Output

4.5.1 Introduction

The buzzer output engine produces a square wave of a configurable duration and frequency when a capacitive sensing input goes from

inactive to active. The feature can be enabled and disabled through the configuration profile. The configuration profile also includes the

settings for active duration and frequency.

CPT007B Data Sheet

Functional Description

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No Touch, Buzzer Inactive

Device Execution

Optimized

Active sample sample

Active process additional

processing process additional

processing

Sleep sleep sleep

Figure 4.5. Effects of the Buzzer on Current Draw — Active Mode, No Touch, Buzzer Inactive

Touch Detected, Buzzer Active

Device Execution

Optimized

Active

Active additional

processing

Sleep

sleep

(stall)

sample

process additional

processing

sleep

(stall)

sample

process

Figure 4.6. Effects of the Buzzer on Current Draw — Active Mode, Touch Detected, Buzzer Active

4.5.2 Buzzer Configuration

If enabled, buzzer output will be routed to the Buzzer pin (pin 7) of the CPT007B. When activated, the buzzer will remain active for

either the duration specified in the configuration profile, or until the last active sensor has qualified a touch release.

The configuration profile supports configuration of output frequencies ranging from 1 kHz to 4 kHz.

The configuration profile can configure the buzzer output pin to either push pull mode or open drain mode.

4.6 Mutually Exclusive Buttons

When enabled through the configuration profile, this system allows one and only one capacitive sensing input to be qualified as active

at a time. The first sensor active will remain the only sensor active until released. The device will internally qualify multiple touch and

release events but will not report them.

CPT007B Data Sheet

Functional Description

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If multiple sensors have been internally qualified as active, the first sensor's touch event will be reported. If a touch event occurs simul-

taneously on more than one sensor, the touch with the highest touch delta will be reported.

If two sensors are qualified as active and the sensor being reported as active qualifies a touch release, the device will report that re-

lease and then report a touch qualification on the still-active second sensor.

In the case where a device has simultaneously qualified more than two active sensors and the reported active sensor qualifies and

reports a release, the remaining qualified sensor with the highest sensor name will then be reported. For example, if sensors CS00,

CS01, and CS02 are active with CS00 externally reported as active, after CS00's release, CS02 would be externally reported as an

active sensor unless the device has already qualified a touch release on CS02.

If both the touch timeout feature and the mutually exclusive button group feature are enabled, the timeout timer will only run on the

touch that is externally reported as being active.

CS00

Device Execution

CS01 CS02

physical touch on pad

touch reported by CPT device

release reported by CPT device

Figure 4.7. Mutually-Exclusive Button Operation

4.7 Self Testing

4.7.1 Introduction

When the self-test feature is enabled through the configuration profile, the device performs a check on all enabled capacitive sensing

inputs upon startup to determine whether the sensing input pins are erroneously shorted to ground or supply. If a short or open is found

on a sensor, the self test feature will signal that an error has been found through a port pin. The feature will then disable that sensor

before beginning touch qualification scans on all sensors left enabled.

4.7.2 Test Failure Signaling

If the self test check reveals an error, the device will toggle the buzzer output pin at a frequency of 2 Hz. This toggling will persist for two

seconds if the device detects one or more self test errors.

CPT007B Data Sheet

Functional Description

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4.8 Configuration Profile

The configuration interface is used by the device to configure default values and performance characteristics that effect capacitive

sensing. The configuration data can be programmed through the Configuration interface (Config Clk and Config Data pins) using [Con-

figurator] in Simplicity Studio.

Several configuration profile templates are available in Simplicity Studio to provide a starting point for development.

CPT007B Data Sheet

Functional Description

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5. Pin Definitions

5.1 CPT007B QFN20 Pin Definitions

20 pin QFN

(Top View)

CS01

CS00

GND

VDD

RSTb /

Config Clk

Config Data

CS06

OUT00

OUT01

OUT02

GND

OUT03

CS02

CS03

CS04

CS05

GND

6 11

BUZZER

OUT06

OUT05

OUT04

Figure 5.1. CPT007B QFN20 Pinout

Table 5.1. Pin Definitions for CPT007B QFN20

Number

Pin Name Description

1 CS01 Analog input

Capactive sensing input 1

2 CS00 Analog input

Capacitive sensing input 0

3 GND Ground

4 VDD Supply power input

5 RSTb /

Config Clk

Active-low reset /

Configuration clock

6 Config Data Configuration data

CPT007B Data Sheet

Pin Definitions

silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 21

Number

Pin Name Description

7 Buzzer Push-pull output

Buzzer output

8 OUT06 Push-pull output

Sensing state of CS06

9 OUT05 Push-pull output

Sensing state of CS05

10 OUT04 Push-pull output

Sensing state of CS04

11 OUT03 Push-pull output

Sensing state of CS03

12 GND Ground

13 OUT02 Push-pull output

Sensing state of CS02

14 OUT01 Push-pull output

Sensing state of CS01

15 OUT00 Push-pull output

Sensing state of CS00

16 CS06 Analog input

Capacitive sensing input 6

17 CS05 Analog input

Capacitive sensing input 5

18 CS04 Analog input

Capacitive sensing input 4

19 CS03 Analog input

Capacitive sensing input 3

20 CS02 Analog input

Capacitive sensing input 2

CPT007B Data Sheet

Pin Definitions

silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 22

5.2 CPT007B QSOP24 Pin Definitions

CS02

CS01

CS00

GND

VDD

RSTb /

Config Clk

Config Data

N/C

CS04

CS05

CS06

OUT00

OUT01

OUT02

OUT03

OUT04

N/C

24 pin QSOP

(Top View)

OUT06

BUZZER

CS03

N/C

OUT05

Figure 5.2. CPT007B QSOP24 Pinout

Table 5.2. Pin Definitions for CPT007B QSOP24

Number

Pin Name Description

1 CS02 Analog input

Capacitive sensing input 2

2 CS01 Analog input

Capactive sensing input 1

3 CS00 Analog input

Capacitive sensing input 0

4 N/C No Connect (leave this pin floating)

5 GND Ground

CPT007B Data Sheet

Pin Definitions

silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 23

Number

Pin Name Description

6 VDD Supply power input

7 N/C No Connect (leave this pin floating)

8 N/C No Connect (leave this pin floating)

9 RSTb /

Config Clk

Active-low reset /

Configuration clock

10 Config Data Configuration data

11 Buzzer Push-pull output

Buzzer output

12 OUT06 Push-pull output

Sensing state of CS06

13 N/C No Connect (leave this pin floating)

14 OUT05 Push-pull output

Sensing state of CS05

15 N/C No Connect (leave this pin floating)

16 OUT04 Push-pull output

Sensing state of CS04

17 OUT03 Push-pull output

Sensing state of CS03

18 OUT02 Push-pull output

Sensing state of CS02

19 OUT01 Push-pull output

Sensing state of CS01

20 OUT00 Push-pull output

Sensing state of CS00

21 CS06 Analog input

Capacitive sensing input 6

22 CS05 Analog input

Capacitive sensing input 5

23 CS04 Analog input

Capacitive sensing input 4

24 CS03 Analog input

Capacitive sensing input 3

CPT007B Data Sheet

Pin Definitions

silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 24

6. QFN20 Package Specifications

6.1 QFN20 Package Dimensions

Figure 6.1. QFN20 Package Drawing

Table 6.1. QFN20 Package Dimensions

Dimension Min Typ Max

A 0.50 0.55 0.60

A1 0.00 — 0.05

b 0.20 0.25 0.30

b1 0.275 0.325 0.375

D 3.00 BSC

D2 1.6 1.70 1.80

e 0.50 BSC

e1 0.513 BSC

E 3.00 BSC

E2 1.60 1.70 1.80

L 0.35 0.40 0.45

CPT007B Data Sheet

QFN20 Package Specifications

silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 25

Dimension Min Typ Max

L1 0.00 — 0.10

aaa — 0.10 —

bbb — 0.10 —

ddd — 0.05 —

eee — — 0.08

Note:

1. All dimensions shown are in millimeters (mm) unless otherwise noted.

2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.

3. This drawing is based upon JEDEC Solid State Product Outline MO-248 but includes custom features which are toleranced per

supplier designation.

4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.

CPT007B Data Sheet

QFN20 Package Specifications

silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 26

6.2 QFN20 PCB Land Pattern

Figure 6.2. QFN20 PCB Land Pattern Drawing

Table 6.2. QFN20 PCB Land Pattern Dimensions

Dimension Min Max

C1 2.70

C2 2.70

C3 2.53

C4 2.53

E 0.50 REF

X1 0.20 0.30

X2 0.24 .034

X3 1.70 1.80

Y1 0.50 0.60

Y2 0.24 0.34

Y3 1.70 1.80

CPT007B Data Sheet

QFN20 Package Specifications

silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 27

Dimension Min Max

Note:

1. All dimensions shown are in millimeters (mm) unless otherwise noted.

2. Dimensioning and Tolerancing is per the ANSI Y14.5M-1994 specification.

3. This Land Pattern Design is based on the IPC-7351 guidelines.

4. All metal pads are to be non-solder mask defined (NSMD). Clearance between the solder mask and the metal pad is to be 60 µm

minimum, all the way around the pad.

5. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should be used to assure good solder paste release.

6. The stencil thickness should be 0.125 mm (5 mils).

7. The ratio of stencil aperture to land pad size should be 1:1 for the perimeter pads.

8. A 2x2 array of 0.75 mm openings on a 0.95 mm pitch should be used for the center pad to assure proper paste volume.

9. A No-Clean, Type-3 solder paste is recommended.

10. The recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.

6.3 QFN20 Package Marking

007B

TTTT

YWW+

Figure 6.3. QFN20 Package Marking

The package marking consists of:

• 007B – The part number designation.

• TTTT – A trace or manufacturing code. The first letter of this code is the hardware revision.

• Y – The last digit of the assembly year.

• WW – The 2-digit workweek when the device was assembled.

• + – Indicates the device is RoHS-compliant.

CPT007B Data Sheet

QFN20 Package Specifications

silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 28

7. QSOP24 Package Specifications

7.1 QSOP24 Package Dimensions

Figure 7.1. QSOP24 Package Drawing

Table 7.1. QSOP24 Package Dimensions

Dimension Min Typ Max

A — — 1.75

A1 0.10 — 0.25

b 0.20 — 0.30

c 0.10 — 0.25

D 8.65 BSC

E 6.00 BSC

E1 3.90 BSC

e 0.635 BSC

L 0.40 — 1.27

theta 0º — 8º

CPT007B Data Sheet

QSOP24 Package Specifications

silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 29

Dimension Min Typ Max

aaa 0.20

bbb 0.18

ccc 0.10

ddd 0.10

Note:

1. All dimensions shown are in millimeters (mm) unless otherwise noted.

2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.

3. This drawing conforms to JEDEC outline MO-137, variation AE.

4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.

CPT007B Data Sheet

QSOP24 Package Specifications

silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 30

7.2 QSOP24 PCB Land Pattern

Figure 7.2. QSOP24 PCB Land Pattern Drawing

Table 7.2. QSOP24 PCB Land Pattern Dimensions

Dimension Min Max

C 5.20 5.30

E 0.635 BSC

X 0.30 0.40

Y 1.50 1.60

Note:

1. All dimensions shown are in millimeters (mm) unless otherwise noted.

2. This land pattern design is based on the IPC-7351 guidelines.

3. All metal pads are to be non-solder mask defined (NSMD). Clearance between the solder mask and the metal pad is to be 60 µm

minimum, all the way around the pad.

4. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should be used to assure good solder paste release.

5. The stencil thickness should be 0.125 mm (5 mils).

6. The ratio of stencil aperture to land pad size should be 1:1 for all perimeter pads.

7. A No-Clean, Type-3 solder paste is recommended.

8. The recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components.

CPT007B Data Sheet

QSOP24 Package Specifications

silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 31

7.3 QSOP24 Package Marking

CPT007B

YYWWTTTTTT

Figure 7.3. QSOP24 Package Marking

The package marking consists of:

• CPT007B – The part number designation.

• TTTTTT – A trace or manufacturing code. The first letter of this code is the hardware revision.

• YY – The last two digits of the assembly year.

• WW – The 2-digit workweek when the device was assembled.

• e3 – Indicates the device is RoHS-compliant.

CPT007B Data Sheet

QSOP24 Package Specifications

silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 32

8. Relevant Application Notes

The following Application Notes are applicable to the CPT007B devices:

•AN957: TouchXpress™ Configuration and Profiling Guide — This application note guides developers through the evaluation and

configuration process of TouchXpress devices using Simplicity Studio [Xpress Configurator] and [Capacitive Sense Profiler].

•AN447: Printed Circuit Design Notes for Capacitive Sensing Performance — This document describes hardware design guidelines

specifically for capacitive sensing applications, including button placement and other layout guidelines.

•AN949: TouchXpress™ Programming Guide — This application note discusses the production programming options available for

TouchXpress devices.

Application Notes can be accessed on the Silicon Labs website (www.silabs.com/interface-appnotes) or in Simplicity Studio using the

[Application Notes] tile.

CPT007B Data Sheet

Relevant Application Notes

silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 33

9. Revision History

9.1 Revision 0.2

August 12th, 2016

Added new revision devices (A02).

Added QSOP24 devices, including pinout information and package drawings.

Added a paragraph to 4.1.12 Active Mode and Sleep Mode Transitions describing the wake-on-touch behavior.

9.2 Revision 0.1

November 21st, 2015

Initial release.

CPT007B Data Sheet

Revision History

silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 34

Table of Contents

1. Feature List and Ordering Information ......................1

2. Typical Connection Diagrams .........................2

2.1 Signal, Analog, and Power Connections .....................2

2.2 Configuration ..............................3

3. Electrical Specifications ...........................4

3.1 Electrical Characteristics ..........................4

3.1.1 Recommended Operating Conditions .....................4

3.1.2 Power Consumption ...........................5

3.1.3 Reset and Supply Monitor .........................6

3.1.4 Configuration Memory ..........................6

3.1.5 Capacitive Sense ............................7

3.1.6 General Purpose and Buzzer Outputs .....................8

3.2 Thermal Conditions ............................8

3.3 Absolute Maximum Ratings .........................9

3.4 Typical Performance Curves .........................10

4. Functional Description........................... 13

4.1 Capacitive Sensing Input ..........................13

4.1.1 Introduction ..............................13

4.1.2 Touch Qualification Criteria.........................13

4.1.3 Thresholds ..............................13

4.1.4 Debounce Counter ...........................14

4.1.5 Touch Deltas .............................14

4.1.6 Auto-Accumulation and Averaging ......................14

4.1.7 Drive strength .............................14

4.1.8 Active Mode Scan Enable .........................14

4.1.9 Active Mode Scan Period .........................14

4.1.10 Active Mode Scan Type .........................15

4.1.11 Sleep Mode Scan Period .........................15

4.1.12 Active Mode and Sleep Mode Transitions ...................16

4.2 Pin Output ...............................16

4.2.1 Introduction ..............................16

4.2.2 Configuration .............................17

4.3 Capacitive Proximity Sensing.........................17

4.3.1 Wake on Proximity ...........................17

4.3.2 Proximity Sensing Output .........................17

4.3.3 Proximity Configuration ..........................17

4.4 Touch Time-Out .............................17

4.5 Buzzer Output ..............................17

4.5.1 Introduction ..............................17

4.5.2 Buzzer Configuration ...........................18

4.6 Mutually Exclusive Buttons .........................18

Table of Contents 35

4.7 Self Testing ..............................19

4.7.1 Introduction ..............................19

4.7.2 Test Failure Signaling ..........................19

4.8 Configuration Profile............................20

5. Pin Definitions .............................. 21

5.1 CPT007B QFN20 Pin Definitions .......................21

5.2 CPT007B QSOP24 Pin Definitions .......................23

6. QFN20 Package Specifications........................ 25

6.1 QFN20 Package Dimensions ........................25

6.2 QFN20 PCB Land Pattern .........................27

6.3 QFN20 Package Marking ..........................28

7. QSOP24 Package Specifications ....................... 29

7.1 QSOP24 Package Dimensions ........................29

7.2 QSOP24 PCB Land Pattern .........................31

7.3 QSOP24 Package Marking .........................32

8. Relevant Application Notes ......................... 33

9. Revision History ............................. 34

9.1 Revision 0.2 ..............................34

9.2 Revision 0.1 ..............................34

Table of Contents .............................. 35

Table of Contents 36

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