A high accuracy and high bandwidth current sense circuit for digitally controlled DC-DC buck converters

David Stack, Anthony Kelly, Thomas Conway

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

This paper presents a high accuracy and high bandwidth current sense circuit for digitally controlled DC-DC buck converters. The circuit uses lossless inductor DCR current sensing and a sigma delta modulator ADC to sense the average current in the inductor to high accuracy. These accurate but low bandwidth measurements are unsuitable for use in feedback control loops as their acquisition delay would limit the achievable loop bandwidth. To solve this issue a Kalman Filter estimates the inductor current at the switching frequency of the converter. The output of the estimator is shown through experimental results to achieve 0.3A static current accuracy when used in a buck converter switching at 1MHz and using a power efficient inductor with a DCR of only 165μOhms.

Original languageEnglish
Title of host publication2016 IEEE Applied Power Electronics Conference and Exposition, APEC 2016
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages1670-1674
Number of pages5
ISBN (Electronic)9781467383936
DOIs
Publication statusPublished - 10 May 2016
Event31st Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2016 - Long Beach, United States
Duration: 20 Mar 201624 Mar 2016

Publication series

NameConference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC
Volume2016-May

Conference

Conference31st Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2016
Country/TerritoryUnited States
CityLong Beach
Period20/03/1624/03/16

Keywords

  • analog to digital conversion
  • Current sensing
  • DC-DC converter
  • digital control
  • point of load

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