基于UC3843升压式程控开关稳压电源的设计

The Design of Booster Programmable Switching Power based on UC3843

系统基于开关电源的工作原理,采用UC3843高性能电流模式控制器实现对Boost升压斩波电路稳压输出。UC3843片内集成有微调的振荡器放电电流(可精确控制占空比)、电流模式工作频率(可到500 kHz)、自动前馈补偿、锁存脉宽调制(可逐周限流)、内部微调的参考电压(带欠压锁定)、欠压锁定(带滞后)、低启动和工作电流等。该系统电路主要包括整流滤波电路、DC-DC变换电路、过流保护电路、稳压反馈电路和单片机控制电路部分。开关电源输出电压可以实现在30 V^36 V之间程控输出,最大输出电流2 A,效率大于等于85%。为了能使系统获得较高的输出电压细分数,又增加了数字电位器控制电路,能对输出电压进行步进值小于1 V的调整。

System is based on switching power supply works,using high-performance current mode controller UC3843 to reailze the Boost booster chopper regulater output.UC3843 integrated with fine-tuning of the oscillator discharge current（which can precisely control the duty cycle）,current-mode frequency（available at 500KHz）,auto-forward compensation,latching pulse width modulation（which can by-week limit）,the internal tuning reference voltage（with undervoltage lockout）,under voltage lockout（with delay）,low startup and operating current.The system circuit includes a rectifier filter circuit,DC-DC converter,current protection circuit,voltage regulator feedback circuit and the MCU control circuit.Switching stabilized power supply output voltage can be realized in the programmable output between 30V^36V,maximum output current of 2A,the efficiency of greater than or equal to 85%.In order to make the system get a higher output voltage division number,increased number of potential control circuit,the output voltage can be less than 1V step adjustment.