© Semiconductor Components Industries, LLC, 2010

January, 2010 − Rev. 2

1

Publication Order Number:

CAT4002B/D

CAT4002B, CAT4003B,

CAT4004B

Constant Current

Programmable LED Driver

with 32 Dimming Levels

Description

The CAT4002B, CAT4003B and CAT4004B provide respectively

two, three and four matched low dropout current sources to drive

LEDs. The CAT400XB requires no external RSET resistor; the LED

current is internally set to 25 mA when the device is first enabled.

Each LED channel includes an individual control loop allowing the

device to handle a wide range of LED forward voltages while still

maintaining tight current matching.

The EN/DIM logic input supports the device enable and a digital

dimming interface for setting the LED channel current with 32 linear

dimming levels.

LEDs can be powered directly from a Lithium−ion battery due to the

low dropout (75 mV at 20 mA) current sinks.

Package options are available including the 4−channel tiny 8−pad

UDFN 2 mm x 2 mm with a max height of 0.55 mm, and 2 or 3−

channel in the 6−lead TSOT−23 and SC−70.

Features

Typical Applications

http://onsemi.com

See detailed ordering information on page 2 of this data

sheet.

ORDERING INFORMATION

SC70−6

SD SUFFIX

CASE 419AD

TSOT23−6

TD SUFFIX

CASE 419AF

UDFN−8

HU2 SUFFIX

CASE 517AW

TYPICAL APPLICATION CIRCUIT

GND

VIN

2.4 V

to

5.5 V

EN/DIM

CAT4002B

VIN

1 mF

LED1

LED2

One Wire

Programming

32 Steps