Design of a high accuracy CMOS temperature sensor

Based on standard CMOS process, a high accuracy and low power temperature sensor is proposed. By adopting high precision proportional current generation modules, vertical parasitic NPN bipolar transistors and improving output end structure, the noise of the circuit is suppressed and the temperature to voltage conversion accuracy is improved. Based on 55nm CMOS process, the circuit has been simulated with Spectre tool. The simulation results show that the sensitivity of the temperature sensor is 3.84 mV/℃ and the inaccuracy is 0.17℃ as the temperature differs from -55℃ to 85℃. The whole circuit dissipates 130μA. After the back-end physical implementation, the layout of the temperature sensor occupies an area of 325μm×64μm. Using STAR_RCXT to extract parasitic parameters from the layout and conduct post-simulation, the result indicates that the inaccuracy is 0.14℃/-0.24℃.