Control of a soft-switched variable frequency buck regulator

摘要

A system and method are provided for controlling a soft-switched modified buck regulator circuit. A voltage (Vx) across or a current through a pull-down switching mechanism within the modified buck regulator circuit is sensed when the pull-down switching mechanism is enabled, where the pull-down switching mechanism is coupled to an upstream end of an inductor and is coupled in parallel with a capacitor. A target time when the pull-down switching mechanism will be disabled (tlf) is computed and the pull-down transistor is disabled at the computed target time.

主权项

1. A method, comprising:
sensing a voltage (Vx) across a pull-down switching mechanism within a modified buck regulator circuit or a current through the pull-down switching mechanism when the pull-down switching mechanism is enabled, wherein the pull-down switching mechanism is coupled to an upstream end of an inductor and the pull-down switching mechanism is coupled in parallel with a capacitor; computing a target time when the pull-down switching mechanism will be disabled (tlf) as a sum of a time (tz) when the voltage (Vx) reaches zero volts, a delay (td) and a phase adjustment delay (ta); and disabling the pull-down switching mechanism at the target time.