Phase lock loop controlled current mode buck converter

摘要

A current mode buck converter has a power stage and a feedback stage. The power stage converts a higher power supply voltage level to a lower output voltage level. The feedback stage is connected with the power stage for controlling the levels of repetitive switching of an output current by phase and frequency locking a switching frequency of the output current to an external clocking signal. The feedback stage controls two levels of output current bounds by transforming a current error to a phase error to prevent error amplification such that an average output current remains constant at any duty cycle.

主权项

1. A feedback apparatus within a current mode buck converter comprising:
a first current level control circuit for establishing a first current level at which a switching stage within a power section of the current mode buck converter switches a direction of a slope of a current flowing through an inductor of the filter section of the power section from a first directional slope to a second oppositely directional slope; and a second current level control circuit for establishing a second current level at which the switching stage within the power section of the current mode buck converter switches the direction of the slope of the current flowing through the inductor of the filter section of the power section from the second oppositely directional slope to the first directional slope; wherein the second current level control circuit phase and frequency locks the current flowing through the inductor with a converter control clock applied to the second current level control circuit such that when the current flowing through the inductor is incorrectly triggered, the second current level is adjusted to lock the phase and frequency of the current flowing through the inductor to the converter control clock.