An auto-calibration technique for BJT-based CMOS temperature sensors

Abstract

To obtain high accuracy, CMOS temperature sensors need to be calibrated. The current available calibration techniques are manual ones. They are time-consuming and expensive. They are not suitable for chip mass production. To solve the problem, we present an individual and automatic calibration technique for BJT-based CMOS temperature sensors. It is an automatic voltage calibration using the trimming circuit based on the successive-approximation algorithm. Experimental results show that after a 2-second auto-calibration, the sensor can achieve an accuracy of −1 °C∼1.5 °C from −40 °C to 100 °C.