A 21b ±40mV range read-out IC for bridge transducers

Precision thermocouples and bridge transducers such as strain gauges and thermistors require read-out ICs with low noise, high accuracy and low drift. In such applications, the sensor and the read-out IC (ROIC) are usually calibrated as a single system, and so in addition to low thermal and 1/f noise, the ROIC should exhibit very low offset and gain drift (a few ppm/°C) to maintain system accuracy over temperature. This paper describes a 21b ROIC that meets this challenge.