A 1.05 V 1.6 mW, 0.45 °C 3σ Resolution ΣΔ Based Temperature Sensor With Parasitic Resistance Compensation in 32 nm Digital CMOS Process

Monitoring temperature in a microprocessor is important for optimal energy consumption under various workloads. This paper presents a temperature sensor in a 32 nm high-k metal gate digital CMOS process for integration in a microprocessor core. The sensor uses a ratio of currents driven into a BJT pair with current chopping to up-convert the temperature signal. A second order sigma-delta (Sigma Delta) 1-bit ADC is used to digitize the chopped signal, which is then down-converted and filtered in the digital domain to obtain a temperature measurement. The sensor operates from -10 to 110 degrees C, achieving a 3 sigma resolution of 0.45 degrees C, and < 5 degrees C inaccuracy without calibration/trimming.