| US 7,499,295 B2 | ||
| Switch mode power supply controllers | ||
| Mahesh Devarahandi Indika de Silva, Cambridge (United Kingdom); Jay Kumar, Cambridge (United Kingdom); and Vinod A. Lalithambika, Cambridge (United Kingdom) | ||
| Assigned to Cambridge Semiconductor Limited, Cambridge (United Kingdom) | ||
| Filed on Jun. 07, 2007, as Appl. No. 11/810,739. | ||
| Application 11/810739 is a continuation of application No. 11/445474, filed on Jun. 01, 2006, granted, now 7,248,487. | ||
| Claims priority of application No. 0610206.5 (GB), filed on May 23, 2006. | ||
| Prior Publication US 2008/0037294 A1, Feb. 14, 2008 | ||
| Int. Cl. H02M 3/335 (2006.01); H02M 7/217 (2006.01) | ||
| U.S. Cl. 363—21.18 [363/21.12; 363/97] | 17 Claims |
| 1. A method of regulating the output of a switch mode power supply (SMPS) operating in a discontinuous conduction mode, the
method comprising:
monitoring a feedback signal from at least one of a primary winding and an auxiliary winding of a magnetic energy storage
device forming part of an output circuit of said SMPS, said feedback signal including a decaying portion representing a decaying
voltage in said output circuit of said SMPS followed by an oscillatory portion when substantially no energy is being transferred
to said SMPS output;
comparing said feedback signal with a reference dependent on a target output voltage to identifying a point in said decaying
portion of said feedback signal defined by said target output voltage for said SMPS;
resetting an integrator at said identified point;
integrating said feedback signal using said integrator starting from said identified point; and
regulating said SMPS output responsive to a comparison, at a defined point in said oscillatory portion of said feedback signal,
of a result of said integrating with a second reference value.
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