LDO过流与温度保护电路的分析与设计

Analysis and Design of Over-Current and Temperature Protect for LDO Circuit

IC芯片集成密度和功耗密度的增大使得过流和温度保护电路十分必要。过流保护电路将检测电流转化为栅压控制开关管;温度保护电路利用PN结正向导通电压的温度特性,促使比较器输出翻转达到保护目的。分别给出了两种保护电路的多种具体实现结构,基于CSMC0.6μm工艺,给出两种保护电路应用于LDO的Spectra模拟结果,并验证了设计结构具有稳定的保护功能。

The increase of integration and power density make over-current and over-temperature protection circuits necessary. Over-current protection circuits convert the detecting current into the gate voltage which controls the switch FET. By the temperature character of PN junction＇s conducting voltage, over-temperature protection circuits can invert the comparator and protect the whole chip. Several practical protection circuits are presented. Based on CSMS 0. 6 μm mix signal mode CMOS process, the Spectra simulation result verifies the function of the two protection circuits that apply on a LDO circuits.