|
CAT3647 Datasheet, PDF (1/14 Pages) Catalyst Semiconductor – 3-Channel Ultra High Efficiency Quad-Mode™ LED Driver with 32 Dimming Levels | |||
|
CAT3647
3-Channel Ultra High Efficiency Quad-Modeâ¢
LED Driver with 32 Dimming Levels
FEATURES
 High efficiency 1.33x charge pump
 Quad-mode charge pump: 1x, 1.33x, 1.5x, 2x
 Drives up to 3 LEDs at 30mA each
 1-wire EZDim⢠32 linear steps
 Power efficiency up to 92%
 Low noise input ripple in all modes
 âZeroâ current shutdown mode
 Soft start and current limiting
 Short circuit protection
 Thermal shutdown protection
 RoHS-compliant 16-pad TQFN package
APPLICATION
 LCD Display Backlight
 Cellular Phones
 Digital Still Cameras
 Handheld Devices
ORDERING INFORMATION
Part Number
CAT3647HV3-GT2
Package
TQFN-16
3mm x 3mm(1)
Notes:
(1) NiPdAu Plated Finish (RoHS-compliant)
(2) Quantity per reel is 2000
Marking
JAAP
PIN CONFIGURATION
(Top View)
DESCRIPTION
The CAT3647 is a high efficiency quad-mode
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 setting the current in all
the LED channels. The 1-wire pulse-dimming interface
supports 32 linear steps from full-scale down to zero
current.
The device is available in the tiny 16-pad TQFN 3mm
x 3mm package with a max height of 0.8mm.
Catalyst Semiconductorâs Quad-Mode⢠1.33x,
charge pump switching architecture is patented.
TYPICAL APPLICATION CIRCUIT
1µF
1µF
16 15 14 13
LED2 1
12 C2-
LED3 2
11 C2+
NC 3
10 C1-
RSET 4
9 C1+
5678
VIN
2.4V CIN
to
5.5V 1µF
1-Wire
EZDimTM
Programming
3.74kâ¦
C1+
VIN
C1- C2+
C2-
VOUT
CAT3647
EN/DIM
RSET
GND
LED1
LED2
LED3
VOUT
COUT
1µF
20mA
© Catalyst Semiconductor, Inc.
1
Characteristics subject to change without notice
Doc. No. MD-5030 Rev. A
|
▷ |