一种宽电源电压快速响应的LDO设计

LDO design for fast response of wide power supply voltage

基于0.35μm工艺,设计了一种工作在15~30 V的宽电源电压的高电源抑制比(PSRR)、快速瞬态响应的线性LDO.该LDO主要包含电源电压预调节模块、基准源模块、误差放大器模块.电源电压预调节模块,降低输入电压波动范围,同时采用了PSRR增强电路,提高LDO的线性稳定性和PSRR;误差放大器模块,采用了一种带正反馈增益增强差分放大器电路,提高了电路的增益,同时采用双环反馈技术,提高LDO的瞬态响应速度.仿真结果表明:输出电压为5 V,PSRR低频时为128 dB,100 kHz时为60 dB,瞬态响应时间约为0.1μs.

Based on the 0.35μm process,a high power supply rejection ratio(PSRR)and fast transient response linear LDO was designed.The LDO consists of a power supply voltage pre-regulation module,a reference source module and an error amplifier module.The power supply voltage pre-regulation module reduces the input voltage fluctuation range.Meanwhile,PSRR enhancement circuit is adopted to improve the linear stability of LDO and PSRR.The error amplifier module adopts a differential amplifier circuit with positive feedback gain to improve the gain of the circuit,and at the same time adopts double-loop feedback technology to improve the transient response speed of LDO.Simulation results show that the output voltage is 5 V,the PSRR low frequency is 128 dB,100 kHz is 60 dB,and the transient response time is about 0.1μs.