Description

This reference design for the differential temperature measurement (DTM) subsystem of heat and cooling meters provides a fully digital alternative to thin-film platinum Resistance Temperature Detector (RTD) sensors. The Precision Temperature Sensor (PTS) achieves Class A RTD sensor accuracy from the –55 ° Celsius to 125 ° Celsius with zero calibration and Class AA accuracy with single-point calibration. The Digital RTD approach streamlines manufacturing processes by using integrated EEPROM memory to store user-defined parameters: eliminating the need to create and maintain accompanying documentation. The Digital RTD simplifies the analog signal processing by eliminating the offset and gain calibration steps of the analog to digital conversion required in traditional DTM systems. Electrostatic discharge (ESD) protection devices on the printed circuit board (PCB) protect against contact or air ESD strikes of up to 30 kV. The small size PCB fits into a 5.2-mm outer diameter metal sheath as commonly used with standard PT100/500/1000 sensors.This digital RTD subsystem works with MSP430™ and SimpleLink™ microcontroller device families: using a four-wire digital interface.