MAX31855 Evaluation Kit Evaluates: MAX31855 General Description The MAX31855 evaluation kit (EV kit) provides the hardware and software (GUI) necessary to evaluate the MAX31855 cold-junction compensated thermocouple-todigital converter. The MAX31855 EV kit comes with a MAX31855KASA+ soldered to the PCB. This is the K-type thermocouple version of the MAX31855. Other thermocouple types can be evaluated by procuring the desired thermocouple, thermocouple socket, and corresponding MAX31855. Contact the factory for free samples of the MAX31855 to match your desired thermocouple type. See the Evaluating Other Thermocouple Types section for part numbers and additional information regarding other thermocouple types. Features S Includes Everything Needed to Evaluate a K-Type Thermocouple S EV Kit Hardware is USB Powered (USB Cable Included) S Windows XP(R), Windows Vista(R), and Windows(R) 7 Operating Systems-Compatible Software S USB HID Interface S Graphical User Interface (GUI) Consists of a Single .EXE File S Second Channel Allows Easy Evaluation of Other Thermocouple Types S RoHS Compliant MAX31855 EV Kit Files EV Kit Contents S Assembled Circuit Board Including MAX31855KASA+ S Mini-USB Cable S K-Type Thermocouple FILE DESCRIPTION MAX31855EVkit.EXE Application program Note: The .EXE file is downloaded as a .ZIP file. Ordering Information appears at end of data sheet. MAX31855 EV Kit Board Windows XP, Windows Vista, and Windows are registered trademarks of Microsoft Corp. For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated's website at www.maximintegrated.com. 19-6072; Rev 0; 10/11 MAX31855 Evaluation Kit Evaluates: MAX31855 Quick Start Note: In the following sections, software-related items are identified by bolding. Text in bold refers to items directly from the EV kit software. Text in bold and underlined refers to items from the Windows operating system. Required Equipment * PC with Windows XP, Windows Vista, or Windows 7 OS with a spare USB port * K-type thermocouple (included) * Mini-USB cable (included) * EV kit hardware Procedure Follow the steps below to get started measuring temperature using the MAX31855 interfaced to a K-type thermocouple. 1) Connect the included K-type thermocouple to J2 (thermocouple socket) of the EV kit hardware. One terminal of the thermocouple is wider than the other, ensuring proper polarity. 2) Ensure that jumper/shunt J4 is installed and is selecting Channel 1. 3) Set the EV kit hardware on a nonconductive surface that ensures nothing on the PCB gets shorted together. 4) Prior to starting the GUI, connect the EV kit hardware to a PC using the supplied mini-USB cable, or equivalent. The COM LED (D2) should flash between red and orange. 5) Windows should automatically begin installing the necessary device driver. The USB interface of the EV kit hardware is configured as an HID device and therefore does not require a unique/custom device driver. Once the driver installation is complete, a Windows message appears near the System Icon menu indicating that the hardware is ready to use. Do not attempt to run the GUI prior to this message. If you do, you must close the application and restart it once the driver installation is complete. On some versions of Windows, Administrator privileges may be required to install the USB device. 6) Go to www.maximintegrated.com/MAX31855EVKIT to download the latest version of the EV kit software, titled MAX31855EVkit.ZIP. Save the EV kit software to a temporary folder. 7) Open the .ZIP file and extract the .EXE file to your desired location. The .EXE file is the actual EV kit GUI and not an install program. You can store the .EXE wherever you like and then uninstall it later by simply deleting the .EXE file. Maxim Integrated 8) Once the device driver installation is complete (from an earlier step), double-click the .EXE file to run the GUI. A message box stating The publisher could not be verified. Are you sure you want to run this software? may appear. If so, click Run. 9) When the GUI appears, the EV Kit Status group box should indicate that the EV kit hardware is ready. Also, the COM LED (D2) should turn green. 10)Click the Single Read button to read the temperature. A valid temperature should be displayed along with all four Alarm Status indicators remaining green. At this point, the EV kit and setup is fully functional and ready to begin evaluating the MAX31855. If any issues arise, see the Troubleshooting section. Detailed Description of Software Figure 1 shows a screenshot of the MAX31855 GUI. EV Kit Status Section On the right-hand side of the GUI is a section titled EV Kit Status. It is used to indicate the status of the communication between the GUI and the EV kit hardware. If everything is working properly, a message indicates that the hardware is present and/or ready. Otherwise, EV Kit not found. is displayed. Thermocouple Type Section The drop-down box in this section is used to select the thermocouple type installed on the EV kit hardware. See Table 1 for the list of possible settings. Out-of-the-box, the hardware contains a K-type version of the MAX31855 along with a K-type thermocouple and socket. Therefore, the drop-down box defaults to the K-type setting. The thermocouple type selection is used by the GUI to calculate the linearized temperature values. Table 1. Thermocouple Types and Sensitivities TYPE SENSITIVITY (V/NC) K* 41.276 J 57.953 N 36.256 S 9.587 T 52.18 E 76.373 R 10.506 *Default setting. 2 MAX31855 Evaluation Kit Evaluates: MAX31855 Figure 1. MAX31855 EV Kit GUI Read from the MAX31855 Section Interfacing to the MAX31855 is simple. The interface is read-only and consists of one 32-bit shift register. When the Single Read button is pressed, all 32 bits are read, parsed, and then displayed. The raw data read from the device is shown in both binary and hexadecimal format in the edit boxes labeled Raw B[31:0]. Furthermore, the four fault bits are analyzed and then their states are indicated in the Alarm Status section. The Raw Thermocouple Temperature and Cold Junction Temperature edit boxes are calculated. And finally, the Linearized Thermocouple Temperature edit Maxim Integrated box is calculated using the sensitivity value and NIST coefficients to compensate for thermocouple nonlinearities. Refer to the MAX31855 IC data sheet for additional information. Multiple Reads Section This section allows the user to enter a desired number of samples (temperature readings) as well as the delay between the samples (in milliseconds) in order to automate temperature readings. It is also possible to write the results to a file by clicking the Log to file checkbox and providing a folder and filename for the comma separated value (.CSV) file to be stored. 3 MAX31855 Evaluation Kit Evaluates: MAX31855 Detailed Description of Hardware The MAX31855 EV kit hardware provides everything needed to evaluate a K-type thermocouple. In addition to a thermocouple and MAX31855, the hardware includes a USB interface that is used to communicate with the PC-based software. An added feature is that the hardware is USB powered, meaning that no power supplies are needed. Thermocouple Channels The EV kit hardware features two thermocouple channels. Channel 1 comes preconfigured with a MAX31855KASA+, K-type thermocouple, and thermocouple socket. A second channel is provided to make it easy to evaluate other thermocouple types. Channel 2 is almost fully populated, missing only the desired MAX31855 version, corresponding thermocouple, and thermocouple socket. A jumper (J4) is used to select the desired channel. The following section describes how to modify the hardware in order to evaluate other thermocouple types. Evaluating Other Thermocouple Types To use Channel 2, see Table 2 for the part numbers of the three items required for the desired thermocouple type. Once the three items have been procured, carefully solder the Maxim device to the footprint labeled U3 and the thermocouple socket to the footprint labeled J3. Obviously, make sure this is done with the board unpowered. Move the jumper, J4, to the Channel 2 position. Finally, connect the thermocouple to the socket. Reconnect the USB cable to the PC and then run the GUI. Select the correct Thermocouple Type from the drop-down box. The hardware and software are now ready to begin evaluation. Description of Channel Selection Jumper The jumper, J4, is used to select the desired channel. See Table 3 for additional details. Table 2. Items Required to Evaluate Other Thermocouple Types TYPE MAXIM PART K MAX31855KASA+ THERMOCOUPLE* SOCKET* 5SRTC-GG-K-24-36 PCC-SMP-K-5 J MAX31855JASA+ 5SRTC-GG-J-24-36 PCC-SMP-J-5 N MAX31855NASA+ NMQIN-010E-6 (unverified) PCC-SMP-N-5 S MAX31855SASA+ -- -- T MAX31855TASA+ 5SRTC-GG-T-24-36 PCC-SMP-T-5 E MAX31855EASA+ 5SRTC-GG-E-24-36 PCC-SMP-E-5 R MAX31855RASA+ -- -- *Thermocouple and socket part numbers are Omega part numbers (www.omega.com). Contact Omega for RoHS part numbers. Table 3. MAX31855 EV Kit Jumper Description (J4) JUMPER JUMPER POSITION DESCRIPTION 1-2* Selects Channel 1. The SO (serial out) pin of the Channel 1 MAX31855 is connected to the USB PC Interface 2-3 Selects Channel 2. The SO (serial out) pin of the Channel 2 MAX31855 is connected to the USB PC Interface J4 *Default position. Maxim Integrated 4 MAX31855 Evaluation Kit Evaluates: MAX31855 Troubleshooting All effort was made to ensure that each EV kit works on the first try directly out of the box. In the rare occasion that a problem is suspected, see the table below to help troubleshoot the issue. SYMPTOM CHECK SOLUTION Is the LED labeled D1 on? If yes, then the electronic fuse, U7, is in a fault state. Inspect for electrical shorts on the PCB and make sure that the PCB is not sitting on a conductive surface. Does the LED labeled D2 turn green when the GUI is running? If not, then exit the GUI and try running it again. If D2 still does not turn green, then exit the GUI and try connecting the USB cable to a different USB port on the PC and wait for a Windows message that states the hardware is ready to use. Run the GUI again. Are any of the LEDs illuminated? If not, then the PCB may not be getting power from USB. Try a different USB cable or a different USB port. GUI appears to work, but the raw data is all zeros. Jumper (J4) Make sure jumper, J4, is installed and connected to the correct channel. The "Fault" and "Open Circuit" indicators are red in the Alarm Status section of the GUI. Is the thermocouple connected? Verify that the thermocouple is connected (to the correct channel). GUI says hardware not found. Maxim Integrated 5 Maxim Integrated 1 1 2 2 GND BLM18PG471 0603 L4 2 BLM18PG471 0603 L2 BLM18PG471 0603 L3 1 2 3 GND BLM18PG471 0603 L1 C7 DNP C4 DNP 1 2 C3 DNP C6 0.01uF C2 0.01uF PCB Layout Notes 1. MAX31855 should be as close as possible to the thermocouple connector. 2. Use as much copper as possible between MAX31855 and connector (PCC-SMP-x-x). 3. Place decoupling CAP close to their voltage supply. 4. Use a large ground plane to improve the device's temperature measurement accuracy. C8 DNP 1 2 GND NUP2105 in2 GND in1 U4 GND NUP2105 in2 GND in1 GND 3 U2 GND NOTE: All R, C and L footprints are 0805 unless otherwise stated. NOTE: Second circuit available for customer to add another type of thermocouple DNP U3 and J3. J3 + PCC-SMP-x-x + PCC-SMP-K-5-ROHS NOTE: U1 and J2 will be populated with K type thermocouple. J2 1 GND GND C5 0.1uF 3V3 1 2 3 4 GND C1 0.1uF U3 NC SO CS SCK MAX31855 DNP GND D TT+ Vccc 1 2 3 8 7 6 5 DNP TP12 SO TP1 8 7 6 5 SO Jum mpe perr J4 MAX31855 GND U1 1 GND NC 2 TSO 3 T+ CS 4 Vcc SCK DNP TP11 SCK CS_BAR TP2 TP3 3V3 3V3 CS SCK SO TP10 TP9 GND TP4 TP5 TP6 TP7 TP8 MAX31855 Evaluation Kit Evaluates: MAX31855 Figure 2. MAX31855 EV Kit Schematic (Sheet 1 of 2) 6 GND GND CS 1M R10 X1 D+ D- C14 DNP BOOTLOAD C15 22pF R5 DNP C16 22pF R11 0 GND R4 4.7K 4 5 R6 3V3 330 C9 0.1uF GND GND 20MHz CRYSTAL_SM 0 R15 0 VBUS ON IN OUT GND FLAG 1 2 3 GND GND GND 3V3 C17 1uF D1 1206 Fault LED GND C10 0.1uF 1uF C11 5VDD GND NOTE: All R, C and L footprints are 0805 unless otherwise stated. OUT BP 28 27 26 25 24 23 22 21 20 19 18 17 16 15 4 5 D+ D- MAX8868EUK33-T SOT23-5 SHDN GND IN U6 P8/1W_PU P7/1W_DQ P5 USB_DET VPO VMO P10/SCL/SCK P11/SDA/SDI VDD GND P9/SDO ENUM D+/VP D-/VM PCB notes: D1, D2, R5 and R9 must be on top layer. PIC18LF2550 SOIC 28-pin MCLR P3 HB COM_LED/BOOT P1 P2 RCV P6/CS GND OCS1 OSC2 P4 UOE PS_VAR Vusb U5 R9 DNP Reset R8 4.7K 3V3 1 2 3 4 R3 5 6 24.9 7 8 9 10 11 Select Fixed Voltage 12 R12 13 14 4.7K D2 R7 330 330 R16 MAX4787EXK+TCT-ND SC70-5 1 R13 0 R14 GREEN N U7 RED D Maxim Integrated LED_BI-COLOR J1 1 Vbus 2 D3 D+ 4 I.D. 5 GND USB_5PIN 1 2 3 C13 0.01uF R2 24.9 R1 24.9 GND C18 1.0uF 3V3 C19 0.1uF SO SCK 3-Wire interface (Read Only) GND C12 1uF 3V3 MAX31855 Evaluation Kit Evaluates: MAX31855 Figure 3. MAX31855 EV Kit Schematic (Sheet 2 of 2) 7 MAX31855 Evaluation Kit Evaluates: MAX31855 Figure 4. MAX31855 EV Kit PCB Layout--Top Figure 5. MAX31855 EV Kit PCB Layout--Bottom Maxim Integrated 8 MAX31855 Evaluation Kit Evaluates: MAX31855 Component List DESIGNATION QTY C1, C5, C9, C10, C19 5 C2, C6, C13 3 DESCRIPTION 0.1FF X7R ceramic capacitors (0805) Venkel C0805X7R160-104KNE 0.01FF X7R ceramic capacitors (0805) Venkel C0805X7R250-103KNE DESIGNATION QTY DESCRIPTION R10 1 1MI Q1% resistor (0805) Venkel CR0805-10W-1004FT R11, R13, R14, R15 4 0I Q1% resistor (0805) Venkel CR0805-10W-000FT R5, R9 0 Do not populate (0805) TP1, TP2, TP3 3 White test points Keystone 5012 TP4-TP8 5 Black test points Keystone 5011 TP9, TP10 2 Red test points Keystone 5010 TP11, TP12 -- Do not populate U1 1 Thermocouple-to-digital converter (8 SO) Maxim MAX31855KASA+ U2, U4 2 TVS diode (SOT-3) NUP2105TL1G U3 0 MAX31855 Do not populate U5 1 PIC18LF2550-I/SO (28 SO) U6 1 Linear regulator (5 SOT23) Maxim MAX8868EUK33+ C3, C4, C7, C8, C14 0 C11, C12, C17, C18 4 1FF X7R ceramic capacitors (0805) Venkel C0805X7R250-105KNE C15, C16 2 22pF ceramic capacitors (0805) Venkel C0805COG101-220KNP D1 1 Red LED (1206) Kingbright APT3216SURCK D2 1 Red/green dual LED Kingbright BM2012SURKCGKC J1 1 5-pin, female Mini-USB 54819-0519 J2 1 K-type thermocouple socket Omega PCC-SMP-K-5-ROHS J3 0 Thermocouple socket Do not populate U7 1 Current-limit switch (5 SC70) Maxim MAX4787EXK+ J4 1 1 x 2 header, 2.54mm pitch 22-28-4360 X1 1 20MHz, 20pF SMT crystal 403I35E20M00000 L1-L4 4 470I ferrite beads (0603) BLM18PG471SN1D -- 1 Jumper/shunt -- 1 Mini-USB cable R1, R2, R3 3 24.9I Q1% resistors (0805) Venkel CR0805-10W-24R9FT -- 1 K-type thermocouple Omega 5SRTC-GG-K-24-36-ROHS R4, R8, R12 3 4.7kI Q1% resistors (0805) Venkel CR0805-10W-4701FT -- 1 PCB: MAX31855 EV Kit R6, R7, R16 3 330I Q1% resistors (0805) Venkel CR0805-10W-3300FT Do not populate (0805) Component Suppliers SUPPLIER PHONE WEBSITE Omega Engineering, Inc. 888-826-6342 www.omega.com Venkel Ltd. 800-950-8365 www.venkel.com Note: Indicate that you are using the MAX31855 when contacting these component suppliers. Maxim Integrated 9 MAX31855 Evaluation Kit Evaluates: MAX31855 Ordering Information PART TYPE MAX31855EVKIT# EV Kit #Denotes a RoHS-compliant device that may include lead that is exempt under the RoHS requirements. Maxim Integrated 10 MAX31855 Evaluation Kit Evaluates: MAX31855 Revision History REVISION NUMBER REVISION DATE 0 10/11 DESCRIPTION Initial release PAGES CHANGED -- Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 (c) 2011 Maxim Integrated Products, Inc. 11 Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. MAX31855 Evaluation Kit Evaluates: MAX31855 Maxim Integrated 12 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Maxim Integrated: MAX31855EVKIT#