US 2014/0368174 A1 · AUDIO FREQUENCY DEADBAND SYSTEM AND METHOD FOR SWITCH MODE REGULATORS OPERATING IN DISCONTINUOUS CONDUCTION MODE

Abstract

A controller for controlling operation of a switching regulator including a modulator, a discontinuous conduction mode (DCM) controller, an audible DCM (ADCM) controller, and a sub-sonic discontinuous conduction mode (SBDCM) controller. The modulator generally operates in a continuous conduction mode. The DCM controller modifies operation to DCM during low loads. The ADCM controller detects when the switching frequency is less than a super-sonic frequency threshold and modifies operation to maintain the switching frequency at a super-sonic frequency level. The SBDCM controller detects a sub-sonic operating condition during ADCM operation and responsively inhibits operation of the ADCM mode controller to allow a SBDCM mode within a sub-sonic switching frequency range. The SBDCM operating mode allows for efficient connected standby operation. The SBDCM controller allows operation to return to other modes when the switching frequency increases above the sub-sonic level.

Claims20

Dependent claims

A controller for controlling operation of a switching regulator, comprising:

a modulator that develops a pulse control signal for controlling pulses on at least one switch control signal to operate in a continuous conduction mode;
a discontinuous conduction mode controller that detects a low load condition and that modifies operation to operate in a discontinuous conduction mode while said low load condition is detected;
an audible discontinuous conduction mode controller that detects a switching frequency that is less than a predetermined super-sonic frequency threshold and that modifies discontinuous conduction mode operation to maintain said switching frequency at a super-sonic frequency level;
and
a sub-sonic discontinuous conduction mode controller that detects a sub-sonic operating condition during audible discontinuous conduction mode operation and that responsively inhibits operation of said audible discontinuous conduction mode controller to allow a sub-sonic discontinuous conduction mode within a sub-sonic switching frequency range.

2 more elements

An electronic device, comprising:

a switching regulator, comprising:
an inductor;
a switch circuit, coupled to said inductor, that is configured to switch current through said inductor to convert an input voltage to an output voltage as controlled by a pulse control signal;
an error amplifier circuit that is configured to detect an error of the output voltage and to provide a compensation signal indicative thereof;
and
a controller, comprising:
a modulator that receives said compensation signal and that provides said pulse control signal to control pulses on at least one switch control signal provided to said switch circuit to operate said switching regulator in a continuous conduction mode;
a discontinuous conduction mode controller that detects a low load condition and that modifies operation of said switching regulator to operate in a discontinuous conduction mode while said low load condition is detected;
an audible discontinuous conduction mode controller that detects a frequency of said pulse control signal that is less than a predetermined super-sonic frequency threshold and that modifies discontinuous conduction mode operation to prevent a switching frequency of said switching regulator from operating within an audible frequency range;
and
a sub-sonic discontinuous conduction mode controller that detects a sub-sonic operating condition during audible discontinuous conduction mode operation and that responsively inhibits operation of said audible discontinuous conduction mode controller to allow said switching regulator to operate at a sub-sonic discontinuous conduction mode.

8 more elements

A method capable of controlling operation of a switching regulator, comprising:

operating in a continuous conduction mode during high load conditions;
operating in a discontinuous conduction mode during low load conditions;
maintaining a switching frequency at a predetermined super-sonic level while a super-sonic threshold condition is detected when operating in the discontinuous conduction mode;
and
disabling said maintaining the switching frequency at the predetermined super-sonic level when a sub-sonic threshold condition is detected to enable a sub-sonic discontinuous conduction mode at sub-sonic switching frequencies.

2 more elements

Dependencies are inferred from the claim text.

Audio frequency deadband system and method for switch mode regulators operating in discontinuous conduction mode

Life of this patent

Audio frequency deadband system and method for switch mode regulators operating in discontinuous conduction mode

Life of this patent

Abstract

Claims20