Acta Metallurgica Sinica(English letters) ›› 2009, Vol. 16 ›› Issue (1): 95-99.doi: 10.1016/S1005-8885(08)60186-7

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High performance white LED driver with single-wire serial-pulse digital dimming

YU Kai, ZOU Xue-cheng, LONG Shuang, WANG Wei-xu   

  1. Department of Electronic Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
  • Received:1900-01-01 Revised:1900-01-01 Online:2009-02-26
  • Contact: YU Kai


A high performance white light emitter diode (LED) driver based on boost converter with novel single-wire serial-pulse digital dimming (SWSP) is proposed. The driver uses external serial programmed pulses and internal clock to simplify brightness control. By embedding a 5-bit digital analog converter (DAC) into the driver, wide dimming range is achieved. Moreover, a new dynamic slope compensation circuit is presented and other key circuits of the driver are optimized to get higher efficiency and fast transition response. A practical circuit is implemented with 0.6 um bipolar complementary-metal-oxide-semiconductor double-diffused-metal-oxide-semiconductor (BCD) technology. The simulation results show that the driver can provide both wide output current from 1.3 mA to 42 mA with 32-level digital dimming and higher efficiency up to 83% while it works at 1 MHz switching frequency with the input voltage variation from 2.7 V to 5.5 V.

Key words:

White LED driver;boost converter;single-wire serial-pulse digital dimming;dynamic slope compensation