CAT4008
8-Channel Constant Current LED Driver
FEATURES
8 Constant current-sink channels
Serial interface up to 25MHz clock frequency
3V to 5.5V logic supply
LED current range from 2mA to 100mA
LED current set by external RSET resistor
300mV LED dropout at 30mA
Thermal shutdown protection
Available in RoHS-compliant 16-lead SOIC (150
and 300mil wide), and TSSOP packages
DESCRIPTION
The CAT4008 is an 8 channel constant current driver
for LED billboard and other general display
applications. LED channel currents are programmed
together via an external RSET resistor. Low output
voltage operation on the LED channels as low as 0.4V
(for 2 to 100mA LED current) allows for more power
efficient designs.
A high-speed 4-wire serial interface of up to 25MHz
clock frequency controls each individual channel using
a shift register and latch configuration. A serial output
data pin (SOUT) allows multiple devices to be
cascaded and programmed via one serial interface.
The device also includes a blanking control pin
(BLANK) that can be used to disable all channels
independently of the interface.
Thermal shutdown protection is incorporated in the
device to disable the LED outputs if the die
temperature exceeds a set limit.
The device is available in the 16-lead SOIC (narrow
and wide), and TSSOP packages.
APPLICATIONS
Billboard Display
Marquee Display
Instrument Display
General Purpose Display
TYPICAL APPLICATION CIRCUIT
VIN
3V to
5.5V
1µF
VDD
CONTROLLER
20mA
LED1 LED2
LED8
BLANK
LATCH
SIN
CLK
GND
CAT4008
SOUT
RSET
to next
device
3.09kΩ
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. MD-5034 Rev. A
CATALYST [ CATALYST SEMICONDUCTOR ]
