A novel current mode variable frequency control for DC-DC converters with adaptive voltage positioning

摘要

This paper presents a novel implementation of current-mode variable-frequency control. The system architecture features a dual-loop feedback and a unique structure with symmetric signal paths for voltage and current signals. The symmetric structure provides practical advantages for integrated controller design to achieve accurate Adaptive Voltage Positioning. The system dynamics is analyzed with the small-signal model. Design guide lines are derived for simple compensation circuits to achieve constant output impedance. With variable switching frequency, the system achieves good dynamic response without requiring high switching frequency at steady state. The system performance was verified by a two-channel interleaved controller chip implemented with CMOS technology.