A 5800- $\mu$ m2 Resistor-Based Temperature Sensor With a One-Point Trimmed Inaccuracy of ±1.2 °C ( $3\sigma$ ) From −50 °C to 105 °C in 65-nm CMOS

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
${\boldsymbol{\mu }}\text{m}^{2}$
and achieves moderate accuracy [±1.2 °C (
$3{\boldsymbol{\sigma }}$
)] over a wide temperature range (−50 °C to 105 °C) after a one-point trim. This is
$2\times $
better than the previous compact resistor-based sensors. Operating from 0.85 to 1.3-V supplies, it consumes 32.5-
${\boldsymbol{\mu }}\text{A}$
and achieves 2.8-mK resolution in a 1-ms conversion time, which corresponds to a resolution FoM of 0.26 pJ
$\cdot \text{K}^{2}$
.