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 μ m2 and achieves moderate accuracy [±1.2 °C (3 σ)] 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-μ A and achieves 2.8-mK resolution in a 1-ms conversion time, which corresponds to a resolution FoM of 0.26 pJ K2.

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.