TPS60230_14 Datasheet, PDF (1/21 Pages) Texas Instruments – WHITE LED CHARGE PUMP CURRENT SOURCE WITH PWM BRIGHTNESS CONTROL

TPS60230
www.ti.com
SLVS516A – MAY 2004 – REVISED JUNE 2004
WHITE LED CHARGE PUMP CURRENT SOURCE
WITH PWM BRIGHTNESS CONTROL
FEATURES
• Regulated Output Current With 0.4%
Matching
• 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 x 3mm QFN Package
APPLICATIONS
• White LED Backlight for Color Displays in
Cellular Phones, Smart Phones, PDAs,
Handheld PCs, Digital Cameras,
and Camcorders
• Key Backlight
DESCRIPTION
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. Ad-
ditionally, 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.
VIN = 2.7 V
to 6.5 V
1 mF
0.47 mF
0.47 mF
VIN
C1+
C1−
C2+
C2−
EN1
EN2
GND
VOUT
D1
D2
D3
D4
D5
ISET
PGND
1 mF
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2004, Texas Instruments Incorporated