Cold-Junction Compensated, 1-Wire Thermocouple-to-Digital Converters

Description

Create a design and simulate using EE-Sim^® tools:

The MAX31850/MAX31851 cold-junction compensated, 1-Wire^® 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 converters resolve temperatures to 0.25°C, allow readings as high as +1768°C and as low as -270°C, and exhibit thermocouple accuracy of 8 LSBs (2°C) for temperatures ranging from -200°C to +700°C.

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 thermocouples distributed over a large area.

Four location address inputs simplify mapping of individual units to specific locations.

Key Features

• Integration Reduces Design Time and Lowers System Cost
  • 14-Bit, 0.25°C Resolution
  • Integrated Cold-Junction Compensation
  • Available for Multiple Thermocouples Types: Supports K-, J-, N-, T-, and E-Type (MAX31850); S- and R-Type (MAX31851)
  • Detects Thermocouple Shorts to GND or VDD
  • Detects Open Thermocouple
• 1-Wire Multiddrop Capability Simplifies Multisensor Systems
  • 1-Wire Interface (Read-Only); Power Can Be Obtained from Interface (Parasite-Powered Mode)

Applications/Uses

• Appliances
• HVAC
• Industrial
• Medical