A 5800-μm² Resistor-Based Temperature Sensor with a One-Point Trimmed Inaccuracy of ±1.2 °c (3σ) from -50 °c to 105 °c in 65-nm CMOS

Abstract

This letter describes a compact resistor-based temperature sensor intended for the thermal monitoring of microprocessors and DRAMs. It consists of an RC poly phase filter (PPF) that is read out by a frequency-locked loop (FLL) based on a dual zero-crossing (ZC) detection scheme. The sensor,fabricated in 65-nm CMOS,occupies 5800 μm² and achieves moderate accuracy [±1.2 °C (3σ)] over a wide temperature range (-50 °C to 105 °C) after a one-point trim. This is 2× better than the previous compact resistor-based sensors. Operating from 0.85 to 1.3-V supplies,it consumes 32.5-μA and achieves 2.8-mK resolution in a 1-ms conversion time,which corresponds to a resolution FoM of 0.26 pJ•K2.