US 8,947,895 B2Granted

Two-peak current control for flyback voltage converters

AssigneeMarvell World Trade Ltd.

InventorsJinho Choi, Hao Peng, Wanfeng Zhang, Tuyen Doan

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Abstract

A system including a switch configured to supply power to a load. A first comparator is configured to compare a first current through the switch to a first threshold. A second comparator is configured to compare the first current through the switch to a second threshold. The second threshold is greater than the first threshold. A current control module is configured to turn off the switch (i) for a first duration in response to the first current through the switch being greater than or equal to the first threshold and (ii) for a second duration in response to the first current through the switch being greater than or equal to the second threshold. The current control module is configured to adjust the second duration based on a difference between an estimated current through the load and a desired current through the load.

Claims11

Dependent claims

A system comprising:

a switch configured to supply power to a load in response to the switch being turned on by pulse width modulation pulses;
a first comparator configured to compare a first current through the switch to a first threshold and generate a first output in response to the first current being greater than or equal to the first threshold;
a second comparator configured to compare the first current through the switch to a second threshold and generate a second output in response to the first current being greater than or equal to the second threshold, wherein the second threshold is greater than the first threshold;
a current estimating module configured to determine an estimated current through the load based on the first current through the switch;
and
a current control module configured to
select the first output or the second output,
turn off the switch based on the first output or the second output, and
adjust a duration for which the second output is selected based on a difference between the estimated current through the load and a desired current through the load.

6 more elements

A method comprising:

supplying power to a load through a switch in response to the switch being turned on by pulse width modulation pulses;
comparing a first current through the switch to a first threshold and generating a first output in response to the first current being greater than or equal to the first threshold;
comparing the first current through the switch to a second threshold and generating a second output in response to the first current being greater than or equal to the second threshold, wherein the second threshold is greater than the first threshold;
determining an estimated current through the load based on the first current through the switch;
select the first output or the second output,
turning off the switch based on the first output or the second output;
and
adjusting a duration for which the second output is selected based on a difference between the estimated current through the load and a desired current through the load.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/404,584Filed 24 Feb 2012 · us provisional application
Priority: 9 Mar 2011
Published: US 2012/0230065 A113 Sep 2012
Granted: 3 Feb 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H02M 3/33523
With automatic control of the output voltage or current, e.g. flyback converters: with galvanic isolation between input and output of both the…
H02M 1/4258
Arrangements for improving power factor of AC input: using a single converter stage both for correction of AC input power factor and generation of…
H05B 45/385
Switched mode power supply [SMPS]: using flyback topology
H02M 1/0022
Control circuits providing compensation of output voltage deviations using feedforward of disturbance parameters: the disturbance parameters being…