一种无需ADC的变步长反馈DC-DC 转换器数控方式

数控DC-DC变换器由于其自身的特点,易于与数字系统进行单片集成.DC-DC的数字控制算法有很多种,其中比较复杂的算法(如PID)需要在片内集成ADC,增加了设计难度.较为简单的控制方案只使用单一的比较器作为反馈输入部件,但动态性能较差.本文在已有的单比较器恒定步长反馈数控Buck转换器的基础上,提出了一类变步长反馈的方案.由于仍使用单比较器或窗口比较器,它的结构简单且易于集成.它借鉴了对分搜索的思路,能根据输出电压反馈的结果动态地改变占空比的变化步长,从而明显地提高了原有恒定步长反馈数控变换器的动态性能.

A Digital Control Scheme for the DC-DC Converter of No-ADC and Variable Voltage-Step Feedback

According to the specific characteristics,digital DC DC converters are easy to be integrated with other digital systems.There exist many digital control algorithms,and some complex algorithms need integrated ADCs,which enhance the difficulty of designing.Some simple schemes use single comparator as the feedback input,showing poor dynamic performance.A new digital control scheme for DC DC converter with variable voltage step feedback was presented and it is based on the Buck converter of no ADC,single comparator and constant voltage step feedback.Because only single comparators or window comparators are used,this scheme is easy to be implemented.It can dynamically alter the duty cycle increments according to the feedback input,which can effectively reduce the dynamic response time under sudden changes of the application environment without enhancing the complexity of the architecture notably.