LED Step-Up Converter
Features
Inherently Matched LED Current
High Efficiency: 87%
Drives Up to Five LEDs from 2.5V Supply
24V Internal Power Switch
Fast 1MHz Switching Frequency
Uses Tiny 1mm Tall Inductors
Requires Only 1μF Output Capacitors
19.5V Over Voltage Protection
SOT-23-6 and TSOT-23-6 Package
Applications
White LED Backlight Display for PDA
Pocket PC
Smart Phones
Handheld Devices
Cellular Phones
General Description
The G5121 is a step-up DC/DC converter specifically
designed to drive up to 5 series white LEDs with constant
current. Series connection of the LEDs provides
identical LED currents resulting in uniform brightness
and eliminates the need for ballast resistors. The
G5121 switches at 1MHz, allowing the use of tiny external
components. A low 0.254V feedback voltage
minimizes power loss in the current setting resistor for
high efficiency. The OVP pin monitors the output voltage
and turns off the converter whenever the LEDs are
open.
The G5121 is available in low profile SOT-23-6 and
TSOT-23-6 package.