CAT3636
6-Channel Quad-Mode
TM
Fractional LED Driver in TQFN3x3
FEATURES
High efficiency 1.33x charge pump
Quad-mode charge pump: 1x, 1.33x, 1.5x, 2x
Drives up to 6 LEDs at 32mA each
1-wire EZDim
TM
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 3mm x 3mm, 16-lead TQFN package
DESCRIPTION
The CAT3636 is a high efficiency quad-mode fractional
charge pump that can drive up to six 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 2.5V to 5.5V.
The EN/SET logic input functions as a chip enable and a
“1-wire” addressable interface for control and current
setting of all LEDs. Three groups of two LEDs can be
configured with independent LED currents between
0.25mA and 32mA.
The device is available in a tiny 16-lead TQFN 3mm x
3mm package with a max height of 0.8mm.
The 1.33x charge pump with two fly capacitors is a
patent pending architecture exclusive to Catalyst
Semiconductor.
APPLICATIONS
LCD Display Backlight
Color RGB LEDs
Cellular Phones
Digital Still Cameras
Handheld Devices
ORDERING INFORMATION
Part
Package
Number
CAT3636 TQFN-16
HV3-T2 3x3 Green*
* Lead Finish: Matte-Tin
Quantity
per Reel
2000
Package
Marking
JAAA
PIN CONFIGURATION
TYPICAL APPLICATION CIRCUIT
© 2007 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. 5020 Rev. C
CATALYST [ CATALYST SEMICONDUCTOR ]
