An Energy-Efficient BJT-Based Temperature Sensor with ±0.8 °C (3 σ ) Inaccuracy from -50 to 150 °C

• Published in: Sensors (Basel, Switzerland) Switzerland), 2022-12, Vol.22 (23), p.9381
• Main Authors: Qin, Chuyun, Huang, Zhenyan, Liu, Yuyan, Li, Jiping, Lin, Ling, Tan, Nianxiong, Yu, Xiaopeng
• Format: Article
• Language: English
• Subjects: Accuracy; Amplifiers, Electronic; Calibration; cascoded FIA; CMOS temperature sensor; Complementary metal oxide semiconductors; Consumer electronics; Digitization; Energy use; energy-efficient; Integrated circuits; leakage; Operational amplifiers; Physical Phenomena; Receivers & amplifiers; Semiconductor chips; Sensors; Signal processing; Silicon; Temperature; Temperature sensors; Transconductance; Transistors
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s22239381

This article presents an energy-efficient BJT-based temperature sensor. The output of sensing front-ends is modulated by employing an incremental Δ-Σ ADC as a readout interface. The cascoded floating-inverter-based dynamic amplifier (FIA) is used as the integrator instead of the conventional operational transconductance amplifier (OTA) to achieve a low power consumption. To enhance the accuracy, chopping and dynamic element matching (DEM) are applied to eliminate the component mismatch error while β-compensation resistor and optimized bias current are used to minimize the effect of β variation. Fabricated in a standard 180-nm CMOS process, this sensor has an active area of 0.13 mm2. While dissipating only 45.7 μW in total, the sensor achieves an inaccuracy of ±0.8 °C (3σ) from -50 °C to 150 °C after one-point calibration.