一种应用于LDO的温度保护电路设计

A temperature protection circuit applied to LDO

温度保护电路是LDO芯片的重要组成部分,能够保证LDO及其负载电路工作在安全温度区间内,避免温度过高而导致芯片损坏。提出了一种应用于LDO的温度保护电路,使芯片工作温度过高时自动关闭供电通路。所提出的温度保护电路利用双极晶体管基极-发射极电压的温度特性,当温度过高时将比较器状态翻转,输出控制信号控制调整管的栅极电压。本电路采用SMIC 0.18μm CMOS工艺进行电路设计并用Spectre软件进行仿真验证,结果显示本电路能够实现130℃关断LDO,温度下降到105℃重启LDO恢复工作,温度迟滞为25℃,工艺角仿真结果显示该电路工艺稳定性良好。

Temperature protection circuit is an essential part of LDO,ensuring LDO and its load circuit working in suitable temperature range,preventing circuit from breaking down due to overheat.This paper presents a temperature protection circuit applied to LDO,turning off the circuit when temperature is too high.Based on the temperature characteristic of base-emitter voltage of bipolar junction transistor(BJT),the temperature protection circuit invert the output of comparator generating control signal to adjust gate voltage of pass transistor while overheat.The proposed circuit is fabricated in 0.18μm CMOS process and experimentally verified by Spectre.Simulation results show that LDO is turned off when temperature is higher than 130℃and turned on when temperature is lower than 105℃.The temperature hysteresis is 25℃.The simulation results of process angle show that the temperature protection circuit is stable.