A 2.98pJ/conversion 0.0023mm2 Dynamic Temperature Sensor with Fully On-Chip Corrections

Abstract

Nowadays, many battery-operated SoCs for loT and environmental monitoring applications are equipped with temperature sensors. In these miniaturized systems, power and area are two critical concerns. One challenge for temperature sensors is that they are sensitive to process corners and random mismatch. Generally, a 2-point trim and systematic non-linear error removal are required, especially for resistor-based sensing front-ends with two types of resistors, whose spread is partially uncorrelated [1], [2]. These corrections are done off-chip and digitally in most publications. In particular for low power sensors, they may consume more power and area than the sensor itself when integrated on-chip [3]. This work presents a resistive temperature sensor that integrates on-chip analog offset, gain and non-linearity correction techniques, while keeping state-of-the-art power and size performance. The prototype consumes 2.98pJ/conversion with an area of 0. <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0023\text{mm}^{2}$</tex> including all the correction techniques and achieves <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$+0.7/-0.6^{\circ}\mathrm{C}$</tex> inaccuracy.