A linear differential output of threshold-based CMOS temperature sensor with enhanced signal range

This work focuses on a new compact 6-transistor CMOS temperature sensor with improved flexibility for achieving target temperature linearity with small die area and low power consumption. The temperature information is provided in a differential output voltage that is based upon the linear dependence of threshold voltage on temperature. Implemented in a 0.18μm process, simulation results indicate the temperature linearity is at the 0.03°C level over the temperature range of -20 °C ~100 °C without any trimming. Over the standard process corners, the untrimmed structure has temperature nonlinearity at the 0.11°C level and Monte Carlo simulation shows the mean nonlinearity with both process and mismatch is also around 0.11°C. Current consumption of this design is around 40μA and active area is approximately 40 μm².