_________________________________________________________________ maxim integrated products 1 general description the MAX31855PMB1 peripheral module provides the necessary hardware to interface the max31855 cold- junction compensated thermocouple-to-digital converter to any system that utilizes pmod k -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 0.25 n c, allows readings as high as +1800 n c and as low as -270 n c, and exhibits thermo - couple accuracy of q 2 n c for temperatures ranging from -200 n c to +700 n c for k-type thermocouples. for full range accuracies, other thermocouple types, and detailed information regarding operation of the ic, r efer to the max31855 ic data sheet. note: k-type thermocouple is not included with maxim peripheral module collections. features s converts output of a k-type thermocouple directly to a signed 14-bit digital word s cold-junction compensation s 14-bit, 0.25 n c 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 MAX31855PMB1 photo 19-6333; rev 0; 5/12 ordering information appears at end of data sheet. pmod is a trademark of digilent inc. MAX31855PMB1 peripheral module for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxims website at www.maxim-ic.com.
_________________________________________________________________ maxim integrated products 2 component list * thermocouple not included with maxim peripheral module collections. component suppliers note: indicate that you are using the MAX31855PMB1 when contacting these component suppliers. detailed description spi interface 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. 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. software and fpga code example software and drivers are available that execute directly without modification on several fpga develop - ment boards that support an integrated or synthesized microprocessor. these boards include the digilent nexys 3, avnet lx9, and avnet zedboard, although other plat - forms 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. the software project (for the sdk) contains several source files intended to accelerate customer evalu - ation and design. these include a base application (maximmodules.c) that demonstrates module function - ality 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. table 1. connector j1 (spi communication) designation qty description c1, c4 0 not installed, ceramic capacitors (0805) c2 1 0.1 f f q 10%, 16v x7r ceramic capacitor (0603) murata grm188r71c104ka01d c3 1 0.01 f f q 10%, 16v x7r ceramic capacitor (0603) murata grm188r71c103ka01d d1 1 tvs diode (3 sot3) on semi nup2105tl1g j1 1 6-pin right-angle male header designation qty description j2 1 k-type thermocouple socket omega pcc-smp-k-5-rohs l1, l2 2 470 i ferrite beads (0603) murata blm18pg471sn1d r1, r2, r3 3 150 i q 5% resistors (0603) u1 1 thermocouple to digital ic (8 so) maxim max31855kasa+ 1 k-type thermocouple, mini plug* 1 pcb: epcb31855pm1 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 pin signal description 1 ss 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 MAX31855PMB1 peripheral module
_________________________________________________________________ maxim integrated products 3 figure 1. MAX31855PMB1 peripheral module schematic vc c gn d gn d 1 t- 2 t+ 3 vc c 4 sc k 5 cs 6 so 7 dn c 8 ma x3 18 55 u1 0. 01uf c3 do no t in stal l c1 do no t in stal l c4 47 0ohm fe rri te b ead l1 om eg a pcc-sm p-k- 5- ro hs so ck e t 1 2 3 nu p2 10 5l d1 po s ne g nc 2 nc 1 th er mo co up le co nn ec to r j2 t+ t- t- t+ vc c gn d miso ss sc k gn d gn d gn d ss sck mis o gn d vc c 15 0 r1 15 0 r3 1 2 3 4 5 6 j1 0. 1uf c2 47 0ohm fe rrit e bead l2 15 0 r2 MAX31855PMB1 peripheral module
_________________________________________________________________ maxim integrated products 4 figure 2. MAX31855PMB1 peripheral module component placement guidecomponent side figure 3. MAX31855PMB1 peripheral module pcb layoutcomponent side figure 4. MAX31855PMB1 peripheral module pcb layoutinner layer 1 (ground) MAX31855PMB1 peripheral module
_________________________________________________________________ maxim integrated products 5 figure 5. MAX31855PMB1 peripheral module pcb layoutinner layer 2 (power) figure 6. MAX31855PMB1 peripheral module pcb layoutsolder side figure 7. MAX31855PMB1 peripheral module component placement guidesolder side MAX31855PMB1 peripheral module
_________________________________________________________________ maxim integrated products 6 ordering information # denotes rohs compliant. part type MAX31855PMB1# peripheral module MAX31855PMB1 peripheral module
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 7 ? 2012 maxim integrated products maxim is a registered trademark of maxim integrated products, inc. revision history revision number revision date description pages changed 0 5/12 initial release MAX31855PMB1 peripheral module
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