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.