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 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> 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.