电流型双频率脉冲序列调制开关变换器

Study of Current-Mode Bi-Frequency Pulse-Train Modulation for Switching Converters

提出了开关变换器电流型双频率脉冲序列调制BF-PTM方法,研究了电流型BF-PTM的控制策略。电流型BF-PTM控制技术无需误差放大器及其相应的补偿网络,具有结构简单,稳定性好,动态响应速度快,电磁干扰噪声水平低,易于实现等优点;此外,通过将电感电流引入到控制环,易于实现电流型BF-PTM控制开关变换器的过电流保护和多变换器的并联均流控制。以电感电流断续导电模式Buck变换器为例,对电流型BF-PTM控制开关变换器进行了研究,仿真及实验结果表明,电流型BF-PTM比传统的电流型PWM具有更快的动态响应速度和更低的电磁干扰噪声。

Current-mode bi-frequency pulse-train modulation （BF-PTM） for switching converters is proposed in this paper. The control strategy of current-mode BF-PTM is studied. It is known that no error amplifier and its compensation circuit are needed for current-mode BF-PTM controlled switching converter, which benefits with simpler control circuit, excellent stability, faster transient response, lower EMI and easy implementation. Introducing the induct current into the control loop makes it easy to realize over current protection and load sharing among switching converters when they are operating in parallel. Buck converter operating in discontinuous conduction mode （DCM）is taken as an example to illustrate the application of current-mode BF-PTM. Finally, simulation and experimental results indicate that current-mode BF-PTM has much faster transient response and lower EMI noise than conventional current-mode pulse width modulation （PWM） technique.