Current Share Control IC Design for Paralleled DC/DC Converters

应用于并行直流转换电源的均流控制芯片设计(英文)

To keep even current distribution among DC/DC converters in a paralleled power system,an automatic master-slave control （AMSC） current sharing scheme is presented,which was implemented by a current share control IC. A current feedback loop for output voltage adjustment is proposed for low signal distortion. Moreover,a special startup control logic is designed to improve startup timing and to speed up the initial current sharing. It was completed in 1.5μm bipolar-CMOS-DMOS （BCD） technology with an area of 3.6mm^2 . Using it,a paralleled power system of two DC/DC converters capable of outputting 12V/3A was built. Experimental results show that the current sharing error at full load is kept within 1%.

为实现并行直流转换电源系统中转换器电流的均衡分布,降低转换器承受的电、热应力,提高系统可靠性,给出一种采用自动主从控制策略的均流方案,并给出了方案实现的关键部件——均流控制芯片的设计.设计中采用电流反馈环路对输出电压进行调整,降低了PCB板级寄生效应对调整信号的影响;并提出一种启动控制电路用以改善系统的启动时序,加速了启动阶段的电流均衡过程.芯片采用1.5μm BCD(Bipolar-CMOS-DMOS)工艺设计实现,面积为3.6mm2.应用该芯片构成了一个由两个直流转换器组成,具有12V/3A输出能力的并行电源系统.测试结果表明,该并行电源系统满负载时均流误差小于1%.