Design of over Temperature Protection Circuit Based on Hysteresis Comparison with High Precision

In this paper, a high-precision over-temperature protection (OTP) circuit based on 55nm CMOS technology is proposed. By introducing external feedback, enable level with logic signal is generated to realize hysteresis of temperature signal. The bandgap reference circuit can work normally under a wide range of power supply voltage and temperature to ensure the stable working state and output of the over temperature protection circuit. The simulation results show that when the temperature exceeds 115°C, the chip stops working, and when the temperature drops to 88°C, the chip works normally, with a hysteresis interval of 27°C. Under different process angle conditions, the temperature coefficient can be kept in a small range, and the output conversion rate of the circuit is 24.99V/°C, which has the characteristics of high precision and high sensitivity. The circuit can suppress the drift of the threshold point caused by the process change, has high precision, and ensures the stability of the circuit performance.