MAX31851RATB+

Sensor And Detector Interfaces Overview

The MAX31851RATB+ is a cold-junction compensated, 1-Wire thermocouple-to-digital converter designed for S- and R-type thermocouples. It integrates a 14-bit ADC, internal reference voltage, and temperature sensor to digitize signals with 0.25°C resolution. The device supports a supply voltage range of 3.0V to 3.7V and operates within an extended temperature range of -40°C to +125°C. Communication occurs via a read-only 1-Wire interface, allowing parasite power operation from the data line. It features fault detection for open circuits and shorts to VDD or GND.

Sensor And Detector Interfaces Feature Summary

• Integrates cold-junction compensation and 14-bit analog-to-digital conversion for S- and R-type thermocouples.
• Utilizes a single-wire 1-Wire interface that supports parasite power mode for simplified wiring.
• Detects thermocouple faults including open circuits and shorts to ground or supply voltage.
• Includes four location address inputs to facilitate mapping multiple units on a shared bus.

Sensor And Detector Interfaces Applications

• Industrial process monitoring
• HVAC systems
• Medical equipment

Sensor And Detector Interfaces Procurement Notes

Verify the specific suffix 'RATB+' against official manufacturer documentation to confirm package type and tape-and-reel configuration. Ensure the ordering code matches the required S-type thermocouple variant. Cross-reference the component marking with the datasheet pinout to validate authenticity before integration into production designs.

Sensor And Detector Interfaces Selection Notes

Select this component when utilizing S-type or R-type thermocouples in environments requiring precise digital conversion. The 1-Wire interface is suitable for distributed sensing where minimizing interconnect complexity is critical. Consider parasite power requirements if external supply lines are unavailable, noting the need for strong pullups during conversions.

Sensor And Detector Interfaces Part Context

This part belongs to the MAX3185x family of thermocouple-to-digital converters manufactured by Analog Devices (Maxim Integrated). While the MAX31850 supports K, J, N, T, and E types, the MAX31851 variant is specifically optimized for high-temperature S and R type applications. Both share identical interfaces and architectural features.

Sensor And Detector Interfaces Replacement Considerations

MAX31850SATA+T: Compatible alternative for S-type thermocouples using SOIC-8 packaging instead of TDFN.

Sensor And Detector Interfaces FAQ

How does the MAX31851 handle power consumption during temperature conversions?

During active conversion, the device draws up to 1.75mA. In parasite power mode, a strong pullup resistor must be activated on the 1-Wire bus within 10µs of issuing the Convert T command to prevent voltage drops.

What is the accuracy specification for S-type thermocouples?

For S-type thermocouples, the gain and offset error is ±2°C between -50°C and +100°C, increasing to ±7°C across the full operating range of -50°C to +1768°C at temperatures between -40°C and +125°C.

Can multiple MAX31851 devices operate on a single bus?

Yes, each device contains a unique 64-bit ROM code, allowing multiple units to function on the same 1-Wire bus. Four address pins allow further logical mapping of individual units to specific locations.