A Compact, Cost-Efficient Linear LED Driver with Selectable PWM and Analog Dimming

In this study, we implemented a compact and cost-efficient linear LED driver for low-power lighting applications. The proposed driver supports both pulse-width modulation and analog dimming to control brightness flexibly. The integrated circuit is implemented using a TSMC 0.5-µm high-voltage mixed-signal LDMOS CMOS process, and key circuit blocks are described. We also fabricated a prototype chip to validate the design. Our experimental results demonstrate that the proposed system performed well in terms of minimal flickering and stable operation under both dimming modes. In the experimental procedure, the maximum LED current was set to 400 mA via RSET adjustment to analyze the effects of internal offset voltages and filtering circuits on current accuracy. The proposed implementation provides a compact and versatile structure suitable for applications in automotive interior lighting, household appliances, and space-constrained UV LED modules, and our results confirm that our approach is practical and feasible.