Patent · US Active

Limit-cycle oscillation (LCO) based switch-mode power supply (SMPS) response evaluation

US7586767B1 · kind B1 · utility

19Cited by
3References
40Claims
0Family size

Inventors

Key dates

Filing dateApr 23, 2008
Grant dateSep 8, 2009
Priority date
Expiry dateApr 23, 2028

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02B70/10
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A limit-cycle oscillation (LCO) based switch-mode power supply (SMPS) response evaluation provides an effective mechanism for determining the characteristic response of an SMPS during normal operation of the SMPS. LCOs are induced in the SMPS loop by introducing a non-linearity in the loop, for example, decreasing the resolution of a pulse-width modulator that controls the SMPS switching circuit. The frequency and amplitude of the LCOs are determined and used to evaluate the characteristic response of the SMPS. In order to produce symmetric LCOs, which are more easily modeled, a zero-offset calibration circuit adjusts values provided to the pulse-width modulator, so that each value introduced during calibration is at the midpoint of a resolution cell. The frequency can be measured by counting between zero-crossings of the LCOs and the amplitude measured by capturing the LCO values immediately prior to each zero-crossing of a first difference of the LCO samples.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.