CAT3643
3-Channel Ultra High Efficiency Quad-Mode™
LED Driver
FEATURES
High efficiency 1.33x charge pump
Quad-mode charge pump: 1x, 1.33x, 1.5x, 2x
Drives up to 3 LEDs at 32mA each
1-wire EZDim™ LED current programming
Power efficiency up to 92%
Low noise input ripple in all modes
“Zero” current shutdown mode
Soft start and current limiting
Short circuit protection
Thermal shutdown protection
Tiny 12-pad XQFN, 12-pad TDFN and 16-pad
TQFN packages
DESCRIPTION
The CAT3643 is a high efficiency Quad-Mode
TM
fractional charge pump that can drive up to three
LEDs programmable by a one wire digital interface.
The inclusion of a 1.33x fractional charge pump mode
increases device efficiency by up to 10% over
traditional 1.5x charge pumps with no added external
capacitors.
Low noise input ripple is achieved by operating at a
constant switching frequency which allows the use of
small external ceramic capacitors. The multi-fractional
charge pump supports a wide range of input voltages
from 2.4V to 5.5V.
The EN/DIM logic input functions as a chip enable and
a digital dimming interface for current setting of all
LEDs. Six different current ratios are available via the
interface.
The device is available in the tiny 12-pad XQFN 2.5 x
2.5mm with max height of 0.4mm or in 16-pad TQFN
or 12-pad TDFN 3mm x 3mm package with a max
height of 0.8mm.
TM
Catalyst Semiconductor’s Quad-Mode 1.33x charge
pump switching architecture is patented.
APPLICATION
LCD Display Backlight
Cellular Phones
Digital Still Cameras
Handheld Devices
ORDERING INFORMATION
Part Number
CAT3643HV2-T2
CAT3643HV2-GT2
CAT3643HV3-T2
CAT3643HV3-GT2
CAT3643HL1-T2
Package
TDFN-12 3 x 3
(1)
TDFN-12 3 x 3
(2)
TQFN-16 3 x 3
(1)
TQFN-16 3 x 3
(2)
Marking
HABF
HABG
JAAE
JAAF
LB
V
IN
2.4V
to
5.5V
C
IN
1µF
EN/DIM
RSET
4.02kΩ
GND
C1+
V
IN
TYPICAL APPLICATION CIRCUIT
1µF
1µF
XQFN-12 2.5 x 2.5
(1)
Notes:
(1) Matte-Tin Plated Finish (RoHS-compliant)
(2)
(3)
NiPdAu Plated Finish (RoHS-compliant)
Quantity per reel is 2000
C1- C2+
C2-
V
OUT
V
OUT
C
OUT
1µF
CAT3643
LED1
LED2
LED3
1-Wire
EZDim
TM
Programming
20mA
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. MD-5022 Rev. E
CATALYST [ CATALYST SEMICONDUCTOR ]
