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

Abstract

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 Si signals. The symmetric structure provides practical advantages d(t) L Rs vout(t) for integrated controller design to achieve accurate Adaptive JL-L Voltage Positioning. The system dynamics is analyzed with the S2 it(t) Rc i (t) small-signal model. Design guide lines are derived for simple Current compensation circuits to achieve constant output impedance. ASensing Amplifie LPF(S) Go With variable switching frequency, the system achieves good dynamic response without requiring high switching frequency y at steady state. The system performance was verified by a Comparator two-channel interleaved controller chip implemented with CMOS technology. Vref C;onstan t VLIroltampifer I.

Modeling and Design Considerations of a Novel High-Gain Peak Current Control Scheme to Achieve Adaptive Voltage Positioning (AVP) for DC Power Converters

“…Therefore, G F can be designed to enhance the low-frequency gains of T v , T i , and T 1 without affecting T 2 . This implies that the dc and low-frequency line regulation can be enhanced without affecting closed-loop output impedance judging from (15) and (16). Therefore, this modeling approach allows a clear picture of how the various control performances are related to T 1 and T 2 , and through the links provided by T i and T v , proper feedback can be designed.…”

“…9, the offset-cancellation gain G F is high at low frequency but equal to unity beyond bandwidth ω LPF . It can be seen from (10)-(12) that G F raises low-frequency gain of T 1 , which improves the low-frequency line regulation according to (16). Thus, this control scheme is called as HGPCC for achieving AVP.…”