Influence of DC conversion ratio over small-signal performances of buck-boost programmable switching regulator

The influence of DC conversion ratio on the dynamic characteristics of a PWM buck-boost programmable regulator using current-injected control (CIC) and the capability of the control scheme to improve performance of the regulator are investigated. The analysis is performed by applying the small-signal model of the regulator to a number of steady-state operating points. The comparison between small-signal characteristics obtained for the same operating points and for different system open-loop gains (SOLGs) is used to evaluate the capability of CIC to improve the performance of the regulator. The analysis shows that considerable improvements can be expected only for frequencies below unity SOLG cross-over frequency and for small DC conversion ratios.<
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