19-6333; Rev 0; 5/12 MAX31855PMB1 Peripheral Module General Description The MAX31855PMB1 peripheral module provides the necessary hardware to interface the MAX31855 coldjunction compensated thermocouple-to-digital converter to any system that utilizes PmodK-compatible expansion ports. The IC performs cold-junction compensation and digitizes the signal from a thermocouple. Versions of the IC are available that operate with a K-, J-, N-, T-, R-, or E-type thermocouple. This module is set up to operate with a K-type thermocouple. The data is output in a signed 14-bit, SPI-compatible, read-only format. This converter resolves temperatures to 0.25NC, allows readings as high as +1800NC and as low as -270NC, and exhibits thermocouple accuracy of Q2NC for temperatures ranging from -200NC to +700NC for K-type thermocouples. For full range accuracies, other thermocouple types, and detailed information regarding operation of the IC, refer to the MAX31855 IC data sheet. Features S Converts Output of a K-Type Thermocouple Directly to a Signed 14-Bit Digital Word S Cold-Junction Compensation S 14-Bit, 0.25NC Resolution S Detects Thermocouple Shorts to GND or VCC S Detects Open Thermocouple S 6-Pin Pmod-Compatible Connector (SPI) S Example Software Written in C for Portability S RoHS Compliant S Proven PCB Layout S Fully Assembled and Tested Ordering Information appears at end of data sheet. Note: K-type thermocouple is not included with Maxim Peripheral Module collections. MAX31855PMB1 Photo Pmod is a trademark of Digilent Inc. __________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX31855PMB1 Peripheral Module Component List DESIGNATION QTY DESCRIPTION DESIGNATION QTY C1, C4 0 Not installed, ceramic capacitors (0805) J2 1 K-type thermocouple socket Omega PCC-SMP-K-5-ROHS C2 1 0.1FF Q10%, 16V X7R ceramic capacitor (0603) Murata GRM188R71C104KA01D L1, L2 2 470I ferrite beads (0603) Murata BLM18PG471SN1D R1, R2, R3 3 150I Q5% resistors (0603) U1 1 Thermocouple to digital IC (8 SO) Maxim MAX31855KASA+ — 1 K-type thermocouple, mini plug* — 1 PCB: EPCB31855PM1 C3 1 0.01FF Q10%, 16V X7R ceramic capacitor (0603) Murata GRM188R71C103KA01D D1 1 TVS diode (3 SOT3) ON Semi NUP2105TL1G J1 1 6-pin right-angle male header DESCRIPTION *Thermocouple not included with Maxim peripheral module collections. Component Suppliers SUPPLIER PHONE WEBSITE Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com Omega Engineering 888-826-6342 www.omega.com ON Semiconductor 602-244-6600 www.onsemi.com Note: Indicate that you are using the MAX31855PMB1 when contacting these component suppliers. Detailed Description Table 1. Connector J1 (SPI Communication) PIN SIGNAL The MAX31855PMB1 peripheral module can plug directly into a Pmod-compatible port (configured for SPI) through connector J1. For information on the SPI protocol, refer to the MAX31855 IC data sheet. 1 SS Connector J1 provides connection of the module to the Pmod host. The pin functions and pin assignments adhere to the Pmod standard recommended by Digilent. See Table 1. SPI Interface Software and FPGA Code Example software and drivers are available that execute directly without modification on several FPGA development boards that support an integrated or synthesized microprocessor. These boards include the Digilent Nexys 3, Avnet LX9, and Avnet ZEDBoard, although other platforms can be added over time. Maxim provides complete Xilinx ISE projects containing HDL, Platform Studio, and SDK projects. In addition, a synthesized bitstream, ready for FPGA download, is provided for the demonstration application. DESCRIPTION Chip enable. Must be asserted low to enable the SPI interface. 2 N.C. Not connected 3 MISO Serial-data output 4 SCK Serial-clock input 5 GND Ground 6 VCC Power supply The software project (for the SDK) contains several source files intended to accelerate customer evaluation and design. These include a base application (maximModules.c) that demonstrates module functionality and uses an API interface (maximDeviceSpecific Utilities.c) to set and access Maxim device functions within a specific module. The source code is written in standard ANSI C format, and all API documentation including theory/operation, register description, and function prototypes are documented in the API interface file (maximDeviceSpecificUtilities.h & .c). The complete software kit is available for download at www.maxim-ic.com. Quick start instructions are also available as a separate document. __________________________________________________________________ Maxim Integrated Products 2 T+ T- J1 VCC GND 1 2 3 4 5 6 4 3 2 1 C2 SCK CS VCC SO T+ DNC T- GND SCK SS 6 5 MISO 7 8 MISO SCK GND VCC SS GND MAX31855 0.1uF 150 150 R2 R3 U1 VCC 150 R1 L1 NUP2105L C4 GND 470ohm Ferrite Bead L2 J2 NC2 NC1 THERMOCOUPLE CONNECTOR Omega PCC-SMP-K-5-ROHS socket POS GND NEG 3 0.01uF 470ohm Ferrite Bead 2 D1 C3 Do Not Install T- T+ Do Not Install C1 GND 1 MAX31855PMB1 Peripheral Module Figure 1. MAX31855PMB1 Peripheral Module Schematic __________________________________________________________________ Maxim Integrated Products 3 MAX31855PMB1 Peripheral Module Figure 2. MAX31855PMB1 Peripheral Module Component Placement Guide—Component Side Figure 3. MAX31855PMB1 Peripheral Module PCB Layout—Component Side Figure 4. MAX31855PMB1 Peripheral Module PCB Layout—Inner Layer 1 (Ground) __________________________________________________________________ Maxim Integrated Products 4 MAX31855PMB1 Peripheral Module Figure 5. MAX31855PMB1 Peripheral Module PCB Layout—Inner Layer 2 (Power) Figure 6. MAX31855PMB1 Peripheral Module PCB Layout—Solder Side Figure 7. MAX31855PMB1 Peripheral Module Component Placement Guide—Solder Side __________________________________________________________________ Maxim Integrated Products 5 MAX31855PMB1 Peripheral Module Ordering Information PART TYPE MAX31855PMB1# Peripheral Module #Denotes RoHS compliant. __________________________________________________________________ Maxim Integrated Products 6 MAX31855PMB1 Peripheral Module Revision History REVISION NUMBER REVISION DATE 0 5/12 DESCRIPTION Initial release PAGES CHANGED — Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2012 Maxim Integrated Products 7 Maxim is a registered trademark of Maxim Integrated Products, Inc.