It is known that ripple-based control of a switching dc-dc converter benefits from a faster transient response than a conventional PWM control switching dc-dc converter. However, ripple-based control switching dc-dc converters may suffer from fast-scale oscillation. In order to achieve fast transient response and ensure stable operation of a switching dc-dc converter over a wide load range, based on a conventional pulse train control technique, a peak capacitor current pulse train (PCC-PT) control technique is proposed in this paper. With a buck converter as an example, the operating modes, steady-state performance and transient respond performance of a PCC-PT controlled buck converter are presented and assessed. To eliminate fast-scale oscillation, circuit and control parameter design consideration are given. An accurate discrete iteration model of a PCC-PT controlled buck converter is established, based on which, the effects of circuit parameters on stability of converter operating in a DCM mode, mixed DCM-CCM mode, and CCM mode are studied. Simulation and experimental results are presented to verify the analysis results.
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