A Two-Stage Automotive LED Driver With Multiple Outputs


This article presents a two-stage automotive LED driver architecture delivering independently regulated output currents to multiple LED strings. The system consists of a multiphase noninverting buck-boost front-end stage, which allows for a wide battery voltage range, followed by high-frequency immittance-network-based LCL-T resonant converters, which operate as current sources over wide output voltage ranges. The two-stage buck-boost + resonant (BB+resonant) architecture takes advantage of the buck and boost capability of both stages, and the flexibility in setting the intermediate bus voltage to minimize losses. Advantages of the BB+resonant architecture include the use of lower voltage rated devices and soft switching in the resonant stage, leading to reduced losses and size. Experimental results are provided for a prototype consisting of a 250-kHz two-phase front-end stage and 2-MHz LCL-T resonant stages delivering independently regulated 1 A currents to four LED strings with N = 1? 18 LEDs. The measured system efficiency is greater than 88% over wide input (8?18 V) and output (3-50 V) voltage ranges, with a peak efficiency of 93%.

See publication:
This publication pertains to:
Charging Stations
Publication Authors:
  • Satyaki Mukherjee
  • Vahid Yousefzadeh
  • Alihossein Sepahvand
  • Montu Doshi
  • Dragan Maksimovic
It appeared in:
Peer-reviewed technical journal
Automotive lighting, current source converter, efficiency optimization, LCL-T resonant converter, LED driver, multiple-output dc–dc converters.