Silicon Temperature Sensor with Inaccuracy of ±0.3℃ from -55 to 125℃
Xiaoxing Feng, Xinan Wang, Feng Jun, Binjie Ge, Xing Zhang · Journal of Semiconductors · 2007
A novel parasitic auto-correction precision silicon temperature sensor in a 0.5μm CMOS process is presented.Simulation shows that its accuracy is within ±03℃ in the full military temperature range from -55 to 125℃ with just one point calibration at 300K.This result is achieved by canceling the base resistor of the CMOS substrate pnp transistors with two structures:three bias temperature sensors and a novel switch-capacitor Sigma-Delta ADC analog front end.The bias current and the emit area of pnp transistors are carefully chosen to avoid serious nonlinearity and a novel analog front end is controlled by four non-overlapping clocks to ease digital processing after ADC.