A Digital Power Factor Controller for Primary-Side-Regulated LED Driver

Yi Jing Lee, Chun Ping Niou, Chun Yu Chen, Chien Hung Tsai

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


In this study, a digital primary-side controller for a flyback light-emitting diode driver with superior line regulation, high power factor (PF), and low total harmonic distortion (THD) was proposed. Conventional constant on-Time control is hampered by input current distortion, leading to high THD. To achieve high PF and low THD, a digital switching frequency limiter with quasi-resonant control was proposed. In addition, owing to the turn-off delay of the MOSFET and propagation delay of the feedback signals, a primary-side-controlled flyback converter experiences poor line regulation. To achieve superior line regulation, delay compensation was proposed and analyzed. A digital controller was realized using a field-programmable gate array and was applied to an input voltage of 90-264~V_{\mathrm {ac}} and an output current of 1 A in a hardware prototype to verify the feasibility of the proposed control solution. The experimental results indicate that line regulation was within ±3%, PF was higher than 0.95, and THD was lower than 5% at universal input voltage.

Original languageEnglish
Article number8957052
Pages (from-to)21813-21822
Number of pages10
JournalIEEE Access
Publication statusPublished - 2020

All Science Journal Classification (ASJC) codes

  • Computer Science(all)
  • Materials Science(all)
  • Engineering(all)


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