CAT3604
4-Channel Regulated Charge Pump
White LED Driver
FEATURES
Drives individually up to 4 LEDs
Output current up to 30mA per LED
Digital control On/Off of each LED
Compatible with supply voltage of 3V to 5.5V
Power efficiency up to 93%
2 modes of operation 1x and 1.5x
Automatic short circuit detect/disable
High-frequency Operation at 1MHz
Low value ceramic capacitors
"604" compatible pinout
Soft start and current limiting
TQFN 16-pad package, 4 x 4mm, 0.8mm max
height
DESCRIPTION
The CAT3604 is a charge pump operating in either 1x
(LDO) mode or 1.5x fractional mode regulating current
through each of the 4 LED pins. Operation at a fixed
high frequency of 1MHz typical allows the use of very
small value ceramic capacitors.
The CAT3604 drives white light-emitting diodes
(LEDs) connected in parallel and provides tightly
matched regulated current to achieve uniformity of
brightness in LCD backlighting applications. An
external resistor R
SET
controls the output current
level. LED currents of up to 30mA are supported over
a range of input supply voltages from 3V to 5.5V,
making the device ideal for battery-powered
applications.
LED dimming can be accomplished by several
methods including using a DC voltage to set the
RSET pin current, applying a PWM signal on the
Control signals, or adding a switched resistor in
parallel with RSET. The Enable input pin allows the
device to be placed in power-down mode with "zero”
quiescent current.
The CAT3604 features short circuit and overcurrent
limiting protection. The device is available in a 16-pad
TQFN package with a max height of 0.8mm.
APPLICATION
Color LCD and keypad Backlighting
Cellular Phones
Handheld Devices
Digital Cameras
PDAs
Portable MP3 players
ORDERING INFORMATION
Part
Number
Package
Quantity
per Reel Marking
2000
2000
G364
CDBA
CAT3604HV4-T2 TQFN-16
(1)
CAT3604HV4-GT2 TQFN-16
(2)
Notes:
(1) Matte-Tin Plated Finish (RoHS-compliant).
(2) NiPdAu Plated Finish (RoHS-compliant).
TYPICAL APPLICATION CIRCUIT
1µF
1µF
C1+
VIN
Battery
V
IN
3V to 4.2V
CIN
1µF
EN
Control 0
Control 1
Control 2
R
SET
24kΩ
EN
CTR0
CTR1
CTR2
RSET
C1- C2+
C2-
VOUT
V
OUT
C
OUT
1µF
20mA
CAT3604
LED1
LED2
LED3
GND
LED4
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. MD-5008 Rev. J
CATALYST [ CATALYST SEMICONDUCTOR ]
