請問CURRENT MODE DC-DC同步Switch的Line Regulation和Load Regulation一問

andywu

請問CURRENT MODE DC-DC同步Switch的Line Regulation和Load Regulation一問

DC-DC同步Switch電路簡單架構不外乎有以下電路構成

BANDGAP,ERRORAMP,COMPARATOR,SHUTDOWN,PROTECT CIRCUIT,LOGIC CIRCUIT,SLOPE...ETC

而主要分別影響Line Regulation和Load Regulation的電路部份是哪些呢?

EXA GAIN不夠高,COMPARATOR不夠快,BANDGAP的PSRR不好  
      
有無大大可以分別影響Line Regulation和Load Regulation的項目

enjoymartin

对于load regulation这个问题，多应该考虑整个环路的响应，并不是哪个部分单独作用的。dcdc中一般有两种构架，电压型和电流型，后者对于load regulation 应该比较好些，当然电流环路会带来稳定性问题，故需要斜波补偿。愿讨论。

baggio

原帖由 andywu 於 2008-11-14 12:01 PM 發表
請問CURRENT MODE DC-DC同步Switch的Line Regulation和Load Regulation一問

DC-DC同步Switch電路簡單架構不外乎有以下電路構成

BANDGAP,ERRORAMP,COMPARATOR,SHUTDOWN,PROTECT CIRCUIT,LOGIC CIRCUIT,SLOPE... ...

你说的这些都应该有影响，但一般考虑整个环路的响应较多。。

andywu

那麼Line Regulation也是要看整個環路,還是可以看某些電路就可知道特性好不好呢

yutian

Several performance enhancements are achieved in peak current-mode control. Key advantages with current mode control are superb line regulation, simple compensation design, robustness to large load variations, and inherent cycle-by-cycle current limiting. Line regulation is the change in the output voltage caused by a change in the input voltage, and is influenced by the gain of the control-to-output transfer function . The gain of the control-to-output transfer function in a current-mode architecture is independent of VIN, thus the line regulation is very good. As a comparison, the control-to-output transfer function in a voltage-mode architecture has a factor of VIN in its expression. This implies that the gain is directly proportional to VIN, and line regulation will suffer.