Combined lossless current sensing for current mode control

In this paper, we provide basic time domain analysis of the combined lossless current sensing scheme. When applied to current mode control, it is noted that the selection of the RC current sensing components is not limited by the matching condition. For reliable steady state operation, the choice of the RC components may be accommodated for better SNR of the current sense signal and current limit requirement. Design equations are developed based on the time domain analysis. Other variations of the lossless current sensing schemes are also presented.