1FEATURES

• Regulated Output Current With 0.4%

Matching

• Drives up to 3 LEDs at 25 mA Each

• LED Brightness Control Through PWM

Control Signal

• High Efficiency by Fractional Conversion

With 1x and 1.5x Modes

• 1 MHz Switching Frequency

• 2.7 V to 6.5 V Operating Input Voltage Range

• Internal Softstart Limits Inrush Current

• Low Input Ripple and Low EMI

• Overcurrent and Overtemperature Protected

• Undervoltage Lockout With Hysteresis

• Ultra-Small 3mm x 3mm QFN Package

APPLICATIONS

• White LED Backlight for Color Displays in

Cellular Phones, Smart Phones, PDAs,

Handheld PCs, Digital Cameras, and

Camcorders

• Keypad Backlight

DESCRIPTION

The TPS60231 charge pump is optimized for white

LED supplies in color display backlight applications.

The device provides a constant current for each LED,

which the initial value can be set by an external resistor. The supply voltage ranges from 2.7 V to

6.5 V and is ideally suited for all applications powered

by a single LI-Ion battery cell or three to four NiCd,

NiMH, or alkaline battery cells. Over an input voltage

range from 3.1 V to 6.5 V, the device provides a high output current of up to 25 mA per LED with a total of

75 mA. High efficiency is achieved by utilizing a

1x/1.5x fractional conversion technique in

combination with very low dropout current sources. In

addition, the current controlled charge pump ensures

low input current ripple and EMI. Only two external

1 μF and two 0.47 μF capacitors are required to build

a complete small and low cost power supply solution.

To reduce board space to a minimum, the device

switches at 1 MHz operating frequency and is

available in a small 16-pin QFN (RGT) package.