Multiphase switching converters operating over wide load ranges

摘要

A system includes a multi-phase switching converter and a converter control module. The multi-phase switching converter receives an input voltage and that supplies an output voltage to a load via a plurality of phases. Each phase includes a plurality of switches, an on-time generator module that determines an on-time of the switches, and a switch control module that controls a switching frequency of the switches based on the on-time and a clock signal, and an inductance that connects the switches to the load. The converter control module varies the switching frequency without varying the on-time or varies the on-time without varying the switching frequency when current through the load varies.

主权项

1. A system comprising:
a multi-phase switching converter that receives an input voltage and that supplies an output voltage to a load via a plurality of phases, wherein each phase comprises:
a plurality of switches;an on-time generator module that determines an on-time of the switches;a switch control module that controls a switching frequency of the switches based on the on-time and a clock signal; andan inductance that connects the switches to the load; a converter control module that varies the switching frequency without varying the on-time or varies the on-time without varying the switching frequency when current through the load varies, an error amplifier that generates an error voltage based on a reference voltage and the output voltage; and a voltage controlled oscillator that generates the clock signal having a frequency based on the error voltage; wherein the switching frequency is based on the frequency of the clock signal; and wherein the converter control module comprises an on-time control module that generates a feed-forward control for the on-time based on the error voltage and a clamping voltage, wherein the clamping voltage is equal to the error voltage at critical conduction.