一种低功耗反激变换器的设计

A Design of Low-power Comsumption Flyback Converter

为了解决反激变换器在不同功率状态下的损耗问题,从硬件参数优化和控制策略改进角度出发,提出了一种低功耗反激变换器的设计方法。在硬件方面,尽可能减小外围电路工作电流,控制电路采用辅助绕组供电,而启动电路仅在电路启动时工作。在控制策略方面选用脉宽调制(PWM)模式与跳周期模式相结合的方式,在大功率状态下选用PWM控制方式,在空载或轻载状态下选用跳周期控制模式,并选用超低功耗单片机MSP430作为控制芯片。反激变换器经优化后,其空载功耗由105 mW降低至25 mW,满载效率也得到了提高。

In order to solve the problem of the consumption of flyback converter under different power conditions,a design method of low power comsumption flyback converter is proposed from the point of view of hardware parameter optimization and control strategy improvement.On the hardware side, try to reduce the working current of the peripheral circuit as far as possible, and the control circuit is powered by the auxiliary winding, and the starting circuit works only when the circuit is starting.Control strategy combines pulse width modulation（PWM） mode and hopping cycle mode,in the high power state, the PWM control mode is effective, and the hopping cycle control mode is effective when in no load or light load condition, ultra low power microcontroller unit MSP430 is selected as the control chip.Experiments show that the no-load power consumption of flyback converter reduced to 25 mW by 105 mW after optimization design, and full load efficiency is greatly improved.