电流模BUCK变换器片上补偿电路设计

Design of On-Chip Compensation Circuit for the Current-Mode BUCK Converter

设计了一种适用于电流模BUCK变换器的片上有源补偿电路。针对陶瓷输出电容具有较低有效串联电阻(ESR)的特点,通过有源电路将频率补偿阻容网络进行等效,克服了稳定性受输出负载影响较大的问题,且节省了PCB面积,减少了芯片引脚。该有源补偿网络基于0.5μm BCD工艺,并应用于一款Buck转换器。在HSPICE上进行Buck芯片系统的稳定型仿真,结果显示理论设计值与实际仿真结果误差在2%以内,系统稳定性良好,负载调整率在3%以内。

On-chip active compensation circuit for the current-mode DC-DC converter is designed.In view of the low equivalent series resistance（ESR）of ceramic output capacitor characteristics,an integrated RC network is proposed to overcome the drawback of traditional stability dependency on load resistance,which saves the PCB space and eliminates the demand of external pins.The active compensation circuit is based on 0.5μm BCD technology,and has been carried on the system simulation on HSPICE.Internal compensation technique provides high loop stability,and load regulation is less than 3%.