LDO中过温保护电路的设计

LDO是一个微型的片上系统,他包括调整管、采样网络、精密基准源、差分放大器、过流保护、过温保护等电路。分析了LDO中过温保护电路的设计,主要介绍了LDO中双极型过温保护电路和CMOS过温保护电路。由于双极器件开发早、工艺相对成熟、稳定,而且用双极工艺可以制造出速度高、驱动能力强、模拟精度高的器件,适用于高精度的模拟集成电路。因此,双极型集成稳压器应用广泛,其设计技术和制造工艺比较成熟和完善。但双极型过温保护电路本身存在热振荡的问题。给出一种新型的CMOS过温保护电路,他具有温度迟滞功能,有效地避免了芯片出现热振荡。

Design of Thermal Protect for LDO

Low Drop Out (LDO)regulator is a micro system on chip,it includes converter,sampling web,reference,differential amplifier,current limit and thermal protect circuits.This paper analyses the design of thermal protect for LDO,then gives a bipolar thermal protect circuit for LDO and a CMOS thermal protect circuit for LDO.A bipolar device may be used in nice analog integrated circuits for stable process,high speed and power drive,so a bipolar LDO is used widely.Nevertheless,a bipolar LDO has the problem"thermal swing".This paper gives a novel CMOS thermal protect circuit for LDO,it has the function"temperature delay"avoiding the problem"thermal swing".