A High-Accuracy Over-Temperature Protection Circuit with Adjustable Threshold for DC-DC

In order to protect DC-DC chip from over-temperature damage, a high-accuracy over-temperature protection circuit is proposed in this paper. The temperature sensor was realized by cascaded transistors to obtain higher detection accuracy. The hysteresis temperature could be set by the voltage divider circuit, which was proportional to the value of the connected resistance. So the implementation of the circuit was simplified. The circuit is fabricated on a 5V180 nm BCD technology. The simulation results show that when the supply voltage is 5V, the over-temperature threshold is about 160°C and the temperature hysteresis is about 30°C. With the supply voltage varying between 2. 5V and 5. 5V, the drift of the over temperature threshold and that of the hysteresis temperature are 1. 03°C and 1. 35°C, respectively.