一种宽输入范围高PSRR线性稳压器设计

A Design of Linear Voltage Regulator with Wide Input Range and High PSRR

针对一般线性稳压器输入电压范围较窄,对电源纹波抑制能力较差的问题,设计了一款宽输入范围、高电源抑制比的线性稳压器。采用折叠式共源共栅结构的误差放大器提升环路增益,与负载相关的零点移动频率补偿结构保证整个环路的稳定性。结果表明:基于180 nm 45 V BCD工艺完成电路设计,在输入电压范围为6~45 V,负载电流范围0~100 mA的条件下,能够稳定输出5 V电压,具有良好的线性调整率。当输入电压为24 V,负载电流为50 mA时,低频段下电源抑制比为85.5 dB。

Aiming at the problem that the input voltage range of the general linear voltage regulator is narrow and the ability to suppress the power supply ripple is poor.A linear voltage regulator with wide input range and high power supply rejection ratio is designed,which adopts a folded cascode error amplifier to improve the loop gain and the load-dependent zero mobile frequency compensation structure to ensure the stability of the whole loop.The results show that the circuit design based on the 180 nm 45 V BCD can stabilize the output voltage of 5 V under the condition of input voltage range of 6~45 V and load current range of 0~100 mA,and has a good linear adjustment rate.When the input voltage is 24 V and the load current is 50 mA,the power supply rejection ratio is 85.5 dB in the low frequency band.