【摘要】 对电流模式控制的反激变换电路进行了研究,建立了工作在电流断续模式下的反激电路小信号模型,给出了基于PWM控制芯片LD7670的单端反激电路的设计实例和电路分析。采用Math CAD对反激变换器控制环路的幅频特性和相频特性进行了分析,对控制环路进行了补偿网络设计,以提高系统的稳定性和瞬态响应。仿真和实验结果证明了模型的有效性,所设计的反激变换电路具有输入电压变化范围宽、动态响应快、电压调整率和负载调整率高的特点。更多还原

【Abstract】 The current mode controlled flyback converter was studied. The small signal model of flyback circuit operating in discontinuous current mode and current-mode control circuit were introduced. The design example and analysis of a flyback converter based on PWM control chip LD7670 were presented. Amplitude 杅requency characteristic and phase-frequency characteristic were simulated by using Math CAD. The stability and dynamic response of switch-mode power supplies were elevated by optimizing its compensation network. The results of the analysis were simulated and verified through experiment. The results show that the flyback converter designed has a wide input voltage range, fast frequency response speed, high voltage and load regulation rates and stable output voltage.更多还原