부산대학교 도서관

This brief presents a novel over-temperature protection (OTP) technique with absolute OTP, dynamic OTP, and the thermal-restart function. Absolute OTP operates when the temperature of the power MOSFET reaches the junction temperature to avoid device breakdown. Dynamic OTP monitors the uneven thermal distribution on the chip. When the temperature difference between the power MOSFET and the controller is large, dynamic OTP is triggered to prevent the performance and lifetime degradation of devices. The chip restarts automatically after the temperature drops below the thermal hysteresis to reduce lifetime loss. Additionally, measurement results demonstrate that the current limitation situation results in the shutdown and the restart of the OTP. The overtemperature threshold and hysteresis of absolute OTP are 175°C and 15°C, dynamic OTP occurs when the temperature difference reaches 76°C, and the restart delayed time is 14.4 ms. The proposed dual over-temperature protection circuit with a thermal-restart function can avoid the damage caused by uneven thermal distributions on the chip, and further improve the reliability of the chip.