一种具有快速瞬态响应、小交调影响和纹波的基于次级纹波控制的单电感多输出电路

A Ripple-Based Single-Inductor Dual-Output Switching Converter with Fast Transient Response Minimized Cross-Regulation and Low Ripple

提出了一种主回路采用峰值电流型控制、次回路采用纹波控制的新型单电感多输出降压型开关电源的设计。这种设计,使单电感多输出的控制回路变得简单,同时也使瞬态响应速度变快,交调影响和纹波变小。其开关频率为2 MHz,两路输出分别为1.8 V和1.2 V,两路负载范围为0～200 mA,实现了全负载可以正常工作。在考虑了各种寄生参数的后仿真条件下,一路负载为200 mA,一路负载从50 mA变化到200 mA,瞬态响应速度小于3μs,交调影响小于0.05 mV/mA,纹波小于30 mV,峰值效率可以达到91%。该芯片已经在CHART 0.18-μm CMOS工艺上设计实现,正在流片验证。

A single-inductor dual-output（SIDO）step-down switching power supply chip has been designed.The main loop uses peak current mode control,and the secondary loop uses ripple control.This design makes the control loop of SIDO simple have fast transient response,minimizes cross-regulation and ripple.With the switching frequency of 2 MHz,two outputs are 1.8 V and 1.2 V,and two load range 0~200 mA,working at full load.Considering all parasitic parameters,simulation results show that the load transient response time is less than 3 μs,the cross-regulation is less than 0.05 mV/mA,the ripple is less than 30 mV and the peak efficiency is as high as 91%.The IC is taped out with CHART 0.18-μm CMOS technology.