Current-Source-Mode Single-Inductor Multiple-Output LED Driver with Single Closed-Loop Control Achieving Independent Dimming Function

Zheng Dong, Chi Kong Tse, S. Y.R. Hui

Research output: Journal article publicationJournal articleAcademic researchpeer-review

28 Citations (Scopus)

Abstract

Single-inductor multiple-output (SIMO) light-emitting diode (LED) drivers have the advantages of being compact, efficient, and low cost. However, the voltage-to-current transfer function of each output of the SIMO converter is not independent, with significant cross regulation issues that necessitate the use of complex closed-loop control for achieving independent dimming function. This paper proposes a current-source-mode (CSM) SIMO dc-dc converter from duality principle, which is shown to be more suited for LED driving due to widened control range of the duty cycle and inherently inductor-less LED driving topology. The outputs of the CSM SIMO dc-dc converter are inherently independent, resulting in very simple control requirement involving only one closed-loop controller for providing the constant current feeder, and several simple open-loop controllers for independent dimmable driving of LEDs. Simultaneous voltage step-up and step-down of multiple outputs is an added feature that simplifies the input power source requirement, especially for portable applications. The whole system is simple, reliable, and low cost. Taking the CSM single-inductor dual-output dc-dc converter as an example, we illustrate the circuit operation and establish a small-signal model for facilitating the design of the feedback control. A direct duty-cycle dimming method is described. Experimental tests are presented for verification.

Original languageEnglish
Article number8352872
Pages (from-to)1198-1209
Number of pages12
JournalIEEE Journal of Emerging and Selected Topics in Power Electronics
Volume6
Issue number3
DOIs
Publication statusPublished - 1 Sep 2018

Keywords

  • Current-source-mode (CSM) converter
  • independent dimming function
  • single-inductor multiple-output (SIMO) converter

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

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