Design of a Buck-Boost Converter without Output Capacitor for Driving Automotive LED

Dong Soo  Lee; Seung Gyun Ha; Byeong Ik  Kim; Chae Young  Kang; Jeong Jin  Roh

doi:10.23075/jicas.2025.11.2.004

Dong Soo Lee Hanyang University
Seung Gyun Ha Hanyang University
Byeong Ik Kim Hanyang University
Chae Young Kang Hanyang University
Jeong Jin Roh Hanyang University

DOI: https://doi.org/10.23075/jicas.2025.11.2.004

Keywords: Automotive LED, Buck-Boost Converter, Output Capacitor

Abstract

LEDs are widely used in automotive lighting systems due to their long lifespan, low power consumption, and fast response characteristics. Consequently, significant research has been conducted on LED drivers. Automotive LED drivers must rapidly adjust their output voltage to accommodate the wide input voltage range of vehicle batteries (7-60V) and the operating conditions of LED matrices. While buck-boost converters are commonly used for this purpose, conventional converters face the risk of LED damage caused by input voltage fluctuations and LED switching, primarily due to the presence of an output capacitor. To overcome this limitation, this study designs of a buck-boost converter without an output capacitor. The designed buck-boost converter utilizes a flying capacitor structure, ensuring that LED current is always supplied through the inductor. Additionally, by adopting LED current-based feedback, both the current regulator and reference voltage controller are eliminated. The designed converter maintains a stable output voltage and LED current across an input voltage range of 7-60V. The chip was fabricated using TSMC’s 180nm BCD process.

Author Biographies

Dong Soo Lee, Hanyang University

Dong Soo Lee received the B.S. degree in electronic engineering from Hanyang University, Ansan, Korea, in 2023. He is currently working toward the M.S. degree in electronic engineering at Hanyang University, Ansan, Korea. His current research interests include integrated power management ICs design and high-performance DC-DC Converter design.

Seung Gyun Ha, Hanyang University

Seung Gyun Ha received the B.S. degree in electronic engineering from Chungju University, Chungju, Korea, in 2023. He is currently working toward the M.S. degree in electronic engineering at Hanyang University, Ansan, Korea. His current research interests include integrated power management ICs design and high-performance DC-DC Converter design.

Byeong Ik Kim, Hanyang University

Byeong Ik Kim received the B.S. degree in electronic engineering from Hanyang University, Ansan, Korea, in 2023. He is currently working toward the M.S. degree in electronic engineering at Hanyang University, Ansan, Korea. His current research interests include integrated power management ICs design and high-performance DC-DC Converter design.

Chae Young Kang, Hanyang University

Chae Young Kang received the B.S. and M.S. degrees in electronic engineering from Hanyang University, Ansan, Korea, in 2022 and 2024, respectively. Her main interests are integrated power management ICs design and high-performance DC-DC Converter design.

Jeong Jin Roh, Hanyang University

Jeong Jin Roh (Senior Member, IEEE) received the B.S. degree in electrical engineering from Hanyang University, Seoul, South Korea, in 1990, the M.S. degree in electrical engineering from Pennsylvania State University, in 1998, and the Ph.D. degree in computer engineering from The University of Texas at Austin, in 2001. From 1990 to 1996, he was as a Senior Circuit Designer for mixed-signal products with Samsung Electronics, Giheung, South Korea. From 2000 to 2001, he was a Senior Analog Designer for delta-sigma data converters with Intel Corporation, Austin, TX, USA. He joined the Faculty of Hanyang University, Ansan, South Korea, in 2001. His research interests include power management circuits and oversampled delta-sigma converters.

Homepage : http://soc.hanyang.ac.kr

Design of a Buck-Boost Converter without Output Capacitor for Driving Automotive LED

Abstract

Author Biographies

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