一种Buck-Boost开关电源环路补偿电路设计

Design of loop compensation circuit for buck-boost switching power supply

设计了一种用于Buck-Boost开关电源电压控制模式的环路补偿电路。该补偿电路是TYPEⅢ型补偿环路,分析了Buck-Boost开关电源功率级建模以及误差放大器补偿环路的电路设计,以此来确保开关电源的稳定性。提出的电路基于0.5μm工艺进行版图设计和仿真验证,后仿真结果表明误差放大器的带宽和相位裕度均满足要求,系统的电压调整率为0.42%,稳定时间为300μs,负载调整率为0.17%,稳定时间为300μs,已经满足设计需求,在一款Buck-Boost开关电源芯片中得到了应用。

A loop compensation circuit for voltage control mode of buck-boost switching power supply is designed.This compensation circuit is TYPEIII compensation loop.This paper analyzes the power level modeling of buck-boost switching power supply and the circuit design of error amplifier compensation loop to ensure the stability of switching power supply.The proposed circuit is based on 0.5μm process for layout design and simulation verification.The results show that the bandwidth and phase margin of the error amplifier meet the requirements.The voltage regulation of the system is 0.42%,the stability time is 300μs,the load regulation is 0.17%,and the stability time is 300μs.It contents the design requirements and applies in a buck-boost switching power supply chip.