A 2548-μm² DTMOST-based temperature sensor with 3σ inaccuracy of ±0.89°C from -40°C to 125°C in 55 nm CMOS

Abstract

This letter presents a 2548-μm² CMOS temperature sensor. It uses a self-regulated capacitively-biased dynamic threshold MOS (DTMOST) and a simple CTAT reference source as front-end to generate a temperature-dependent clock signal, which is then fed into a counter-based frequency-to-digital converter (FDC), yielding a digital readout. Implemented in a standard 55 nm CMOS process, the sensor has 942.5 μm² front-end area, achieves an inaccuracy of ±0.89°C (3σ) from -40°C to 125°C after one-point calibration in batch. It consumes 6.15 μW and achieves a resolution of 14.5 mK and a resolution figure of merit (FoM) of 2.1 pJ・K².