A high current accuracy boost white LED driver based on offset calibration technique

Yuan Ta Hsieh, Bin-Da Liu, Jian Fu Wu, Chiao Li Fang, Hann Huei Tsai, Ying Zong Juang

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)

Abstract

The current accuracy and power efficiency of a boost white light-emitting-diode (WLED) driver are usually design tradeoffs since the power efficiency is inversely proportional to the reference voltage, whereas the current accuracy is proportional to the reference voltage. Traditionally, a boost WLED driver with high current accuracy and high power efficiency demand a large chip area because mismatch decreases with increasing size. This paper proposes an offset calibration technique to improve both current accuracy and power efficiency while keeping the chip area relatively small. An overvoltage protection (OVP) circuit and an overcurrent protection (OCP) circuit prevent the proposed driver from being damaged due to WLED failure. The design is fabricated in a Taiwan Semiconductor Manufacturing Company 0.25-μm 60-V bipolarCMOSdouble-diffused-MOS process. The measurement results show that the current variation is less than 1% when the input voltage and the number of loaded WLEDs are varied in a wide range. The maximum power conversion efficiency is 86.7% at a 5-V input with four loaded WLEDs. The OVP is 58 V, and the OCP is 2 A.

Original languageEnglish
Article number5746618
Pages (from-to)244-248
Number of pages5
JournalIEEE Transactions on Circuits and Systems II: Express Briefs
Volume58
Issue number4
DOIs
Publication statusPublished - 2011 Apr 1

All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering

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