The TPS60230 charge pump is optimized for white
LED supplies in backlit color display applications. The
device provides a constant current, set by an external
resistor, for each LED. 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.
The TPS60230 provides up to 25 mA per LED, for a
total of 125 mA, for input voltages ranging from 3.1 V
to 6.5 V. High efficiency is achieved by utilizing a
1x/1.5x fractional conversion technique in combi-
nation with very low dropout current sources. Additionally,
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.
The TP60230 switches at 1 MHz operating frequency
and is available in a small 16-pin QFN (RGT)
package to keep board space to a minimum.
- Regulated Output Current With 0.3% Matching Over Temperature
- Drives up to 5 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 × 3mm QFN Package
- APPLICATIONS
- White LED Backlight for Color Displays in Cellular Phones, Smart Phones, PDAs, Handheld PCs, Digital Cameras, and Camcorders
- Key Backlight