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.

A 280nW leakage-ratio-based CMOS temperature sensor with supply/clock sensitivity suppression

“…In recent years, time-mode CMOS temperature sensors have become popular due to their low supply voltage, easy readout, and small footprint features [14,15,16,17,18,19,20,21,22,23,24,25,26,27]. However, the time-mode information depends on the charging and discharging time.…”

An exponent-scalable method for very small capacitance spread and large time constant of switched-capacitor integrator

“…For decades, switched-capacitor (SC) integrators have been widely used for sensors calibration [1], biomedical instrument [2], sigma-delta modulator [3,4], etc. In high-Q SC filters processing low frequency signal, very small pole-to-sampling frequency ratio is realized by very large time-constant (VLT) SC integrators [5,6], whose capacitance spread (CS), defined by the ratio of the largest and smallest capacitors, can be very large.…”