A 12.6-pJ/Conversion Temperature Sensor With 0.98-mV/K Temperature-Voltage Sensitivity

This brief proposes a low-power and energy-efficient CMOS temperature sensor circuit. It presents an integrated transducer and readout design with a novel 1-bit temperature-voltage (T-V) comparator-embedded 12-bit SAR ADC. Thanks to the proposed load-capacitor-imbalance technique, the temperature-voltage sensitivity is increased, thus improving system energy efficiency. Besides, an on-chip PTAT voltage source was introduced to further enhance temperature-voltage sensitivity and eliminate the need for additional off-chip voltage references in temperature-voltage conversion. According to the post-layout simulation, the temperature sensor achieves a 0.98-mV/K T-V sensitivity under a 28-nm CMOS process, demonstrating over 50% improvement compared to prior arts. It consumes 12.6-pJ per conversion, achieving a 0.15K resolution under a 0.6-V power supply, thus realizing a state-of-the-art resolution Figure-of-Merit (FoM) of 0.29-pJ $\cdot $ K2.