LED lighting control driver design and development of the 12V‐12W class using the
voltage controlled ring oscillator

Ki-Soo Kwon
Department of Electronic Engineering
Graduate School
Yeungnam University


Abstract
This paper presents a Pulse Width Modulation (PWM) controller and circuits for the high power LED (Light Emitting Diode) driver. The controller is available for the remote control through four major operation modes of ON, OFF, Emergency and Power saving using the serial communication. The entire driver circuits use a DC‐DC converter such a Boost topology with dimming, current, thermal control and communication functions for hallway lighting and automobile applications. According to the type and power of LED, a driver IC has already been developed and is produced. This driver IC makes the constant current and constant voltage available. However, if the LED driver allows delicate dimming control and thermal dissipation through allowance of LED off time, PWM control is needed. Therefore, a MCU (Microcontroller unit) for the PWM control as well as a driver IC for driving LEDs is needed. If this operation is embedded at this driver IC, the expense can be reduced. The LED controller integrated circuit (IC) was designed, simulated and fabricated in 0.35μm Magnachip/Hynix.