采用内环平均电流共享的多相电源分析与设计

多相电源的设计需要分析其动态特性和系统稳定性。该文在单相电源的基础上建立了多相电源的小信号模型,并利用控制理论推导了系统的传输函数。利用Bode图分析方法,对多相电源的小信号稳定性和动态特性做了系统上的分析,特别考虑了电压反馈网络和电流反馈网络的各个参数对系统稳定性的影响。在此基础上,设计了多相电源芯片,并指出内环平均电流共享相对于外环平均电流共享的优点:面积小三分之一,功耗小二分之一,同时系统传输函数只有3个极点,系统稳定性要更好。

Multiphase converter with inner loop average current sharing

This paper describes stability and dynamic performance of a multiphase converter with inner loop average current sharing. The small signal model of the multiphase converter and the transfer function were based on the model of a single channel with a design example showing how to obtain a stable current sharing loop. A systematic approach is presented for assessing the small signal stability and dynamic performance of the multiphase converter. The converter with inner loop average current sharing needs only one compensation network, so the chip area is reduced by one third while the power dissipation is half of a converter with outer loop current sharing. In addition, since the compensation network has only three poles, the current feedback loop is more stable than with outer loop average current sharing.