MAX31850 Datasheet, PDF (1/25 Pages) Maxim Integrated Products – Cold-Junction Compensated, 1-Wire Thermocouple-to-Digital Converters

EVALUATION KIT AVAILABLE
MAX31850/MAX31851
Cold-Junction Compensated, 1-Wire
Thermocouple-to-Digital Converters
General Description
The MAX31850/MAX31851 cold-junction compensat-
ed, 1-Wire^M thermocouple-to-digital converters perform
cold-junction compensation and digitize the signal from
a K-, J-, N-, T-, S-, R-, or E-type thermocouple. The con-
verters resolve temperatures to 0.25NC, allow readings
as high as +1768NC and as low as -270NC, and exhibit
thermocouple accuracy of 8 LSBs (2NC) for temperatures
ranging from -200NC to +700NC.
Communication with the master microcontroller is over a
1-Wire bus that by definition requires only one data line
(and ground) for communication. Operating power can
be obtained directly from the data line (“parasite power”),
eliminating the need for an external power supply.
Each device has a unique 64-bit serial code, which
allows multiple units to function on the same 1-Wire bus.
Therefore, it is simple to use one microcontroller (the
master device) to monitor temperature from many ther-
mocouples distributed over a large area.
Four location address inputs simplify mapping of
individual units to specific locations.
Features
S Cold-Junction Compensation
S 14-Bit, 0.25NC Resolution
S Versions Available for K-, J-, N-, T-, S-, R-, and
E-Type Thermocouples (see Table 1)
S 1-Wire Interface (Read-Only); Power Can Be
Obtained from Interface (Parasite-Powered Mode)
S Detects Thermocouple Shorts to GND or V_DD
S Detects Open Thermocouple
Applications
Industrial
Appliances
HVAC
Medical
Ordering Information appears at end of data sheet.
Block Diagram
S5
COLD-JUCTION
COMPENSATION
T+
S4
T-
S1
FAULT
S2
DETECTION
MAX31850
MAX31851
DQ
64-BIT ROM
AND
1-Wire PORT
PARASITE-
POWER
CIRCUIT
CPP
ADC
POWER-
SUPPLY
VDD
SENSE
MEMORY
CONTROL LOGIC
S3
REFERENCE
SCRATCHPAD
VOLTAGE
ADDRESS PIN INPUT
GND
AD0 AD1 AD2 AD3
1-Wire is a registered trademark of Maxim Integrated Products, Inc.
For related parts and recommended products to use with this part, refer to: www.maximintegrated.com/MAX31850.related
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.
19-6725; Rev 0; 6/13