Impact of Process Variation on the Accuracy of Digital CMOS Temperature Sensor

This paper discusses the impact of process variation on the accuracy of a digital smart temperature sensor which we designed based on a 0.35um CMOS process without employing any calibration techniques. It’s found that, if the sensor circuit is properly designed, the process variation of MOS transistors has little impact on sensor accuracy in a temperature range of $-40^{\circ}\mathrm{C} \sim 120^{\circ}\mathrm{C}$, whereas the process variation of on-chip bipolar junction transistors and resistors produce considerable errors.