US 8,912,773 B2 · Synchronous buck converter including multi-mode control for light load efficiency and related method

Abstract

According to one embodiment, a synchronous buck converter comprises a multi-mode control circuit for detecting a load condition of a variable load, an output stage driven by the multi-mode control circuit, wherein the variable load is coupled to the output stage, and a feedback circuit connected between the output stage and the multi-mode control circuit. The multi-mode control circuit is configured to adjust a current provided by the output stage to the variable load based on the load condition. In one embodiment, the multi-mode control circuit selectably uses one of at least a first control mode and a second control mode according to the load condition, wherein the first control mode is a pulse-width modulation (PWM) mode selected for switching efficiency when the load condition is heavy and the second control mode is an adaptive ON-time (AOT) mode selected for switching efficiency when the load condition is light.

Claims20

Dependent claims

A synchronous buck converter comprising:

a multi-mode control circuit for detecting a load condition of a variable load;
an output stage driven by said multi-mode control circuit;
said variable load coupled to said output stage;
said multi-mode control circuit including a first control circuitry for driving said output stage using a first control mode and a second control circuitry different from said first control circuitry for driving said output stage using it second control mode;
a feedback circuit connected between said output stage and said multi-mode control circuit, said feedback circuit configured to provide a first feedback signal to said first control circuitry using a first feedback path, and to provide a second feedback signal to said second control circuitry using a second feedback path;
wherein said multi-mode control circuit adjusts a current provided by said output stage to said variable load based on said load condition.

3 more elements

A method for use in a synchronous buck converter, said method comprising:

driving an output stage of said synchronous buck converter by a multi-mode control circuit including a first control circuitry for driving said output stage using a first control mode and a second control circuitry different from said first control circuitry for driving said output stage using a second control mode;
detecting by said multi-mode control circuit a load condition of a variable load coupled to said output stage;
providing feedback from said output stage to said multi-mode control circuit by a feedback circuit of said synchronous buck converter, said feedback circuit configured to provide a first feedback signal to said first control circuitry using a first feedback path, and to provide a second feedback signal to said second control circuitry using a second feedback path;
adjusting by said multi-mode control circuit a current provided by said output stage to said variable load based on said load condition.

1 more element

Dependencies are inferred from the claim text.

Synchronous buck converter including multi-mode control for light load efficiency and related method

Life of this patent

Synchronous buck converter including multi-mode control for light load efficiency and related method

Life of this patent

Abstract

Claims20