一种带过温过流过压保护的LDO设计

Design of LDO with Thermal Over-Current and Over-Voltage Protection

摘要: 本文设计了一种带过温、过流和过压保护的低压差线性调整器,并采用增加零点方式进行补偿.电路设计采用2μm Bipolar工艺,用Hspice进行仿真验证.仿真结果表明,过温保护电路可以实现对电路的保护.当温度高于140℃时,过温保护电路将调整管关断,温度下降到105℃时,LDO恢复正常工作.最大输出电流为5A,超过最大输出电流时,过流保护电路将调整管关断.负载调整率不超过1%;电源调整率不超过0.1%..

Abstract: a kind of LDO with thermal protection,over-current protection and over-voltage protection is designed, and the main loop circuit increases a zero for frequency compensatioa The circuit is designed based on CSMC 2μm Bipolar process and simulated with Hspice.Simulation results shows that thermal protection could achieve protection for the circuit.When the temperature is higher than 140℃,thermal protection circuit would shut off the regulator,and when the temperature drops down to 105℃,the LDO works again.The maximum output current is 5A,and when output current exceeds the maximum output current,over-current protection circuit would shut off the regulator.When load ranges from 10mA to 5A,Changes in the output voltage does not exceed 32mV;When input voltage ranges from 3.8V to 6V,Changes in the output voltage does not exceed 3mV.