General Description

The RT8549L is a high efficiency Boost converter with

4-CH LED driver supporting 60V maximum output voltage.

It is designed for LCD panel applications that employs

LED as lighting sources. The Boost converter generates

a suitable output voltage to drive four LED strings in parallel

and supports up to 18 LEDs per string.

The RT8549L supports a wide input voltage range from

4.2V to 24V and provides a SMBus interface to control

the LED brightness dimming mode, operating frequency

and LED currents. The internal 150mΩ, 60V power switch

with current-mode control provides high efficiency

operation.

The RT8549L is available in the WDFN-16L 5x5 package

to achieve optimized solution for PCB space.

Applications

 UMPC and Notebook Computer Backlight

Features

 Wide Operating Input Voltage : 4.2V to 24V

 Max 60V Output Voltage

 3 LED Current Accuracy

 2 LED Current Matching

 Low Drop Output 120mA/0.4V Current Sink

 SMBus Programs LED Current, Switching

Frequency, Dimming Mode

 LED Current : 22.58mA to 180mA

 Switching Frequency : 200kHz to 900kHz

 Dimming Mode : PWM, DC, Mixed-Mode

 Built-in Input UVP, Output OVP, OCP, and Soft-Start

 Support LED Hot-plug, Open/Short Detection

 Low EMI, Low Acoustic Noise

 16-Load WDFN Package

 RoHS Compliant and Halogen Free