Abstract: In this paper, a high performance temperature protection for GaN HEMT gate driver chip is designed, which can accurately respond and output protection signal to ensure the circuit safety. The over temperature protection uses two temperature detection circuits to collect the voltage value of the temperature signal and amplify the voltage difference, then after comparative filtering, a Schmitt trigger with hysteresis function outputs the shaping protection signal, which can overcome the influence of common mode noise and temperature stress. The design is based on CSMC 0.18 μm BCD process, and the circuit design verification and testing are completed. The results show that the circuit function is correct and can meet the application requirements of GaN HEMT gate driver.