电流模式变换器的完整小信号模型及环路补偿

Whole Small Signal Model and Compensation for Regulators With Current Programmed Mode

基于连续电感电流条件下的峰值电流模式PWM控制降压变换器的功率级和控制级的小信号模型,得到了它在1/2开关频率以内的包括电流内环和电压外环的完整小信号模型。利用此模型从理论上分析了电流模式的优点,从电流内环环路增益的角度解释了斜坡补偿的必要性。通过推导电压外环环路增益表达式,提出了一种有意义的电压环路补偿方法,并给出它的验证结果。

A whole small signal model of current programmed mode （CPM） within half of switching frequency is presented in this paper, which contains models of current loop and voltage loop. The advantages of current programmed mode are described according to this model. Then, the necessity of slope compensation is proved by the derivation of loop gain of current loop. And a significative method of voltage loop compensation is proposed through the derivation of loop gain of voltage loop. Simulation results of the compensation are given to demonstrate the effectiveness of the theoretical outcome in the end.