© Semiconductor Components Industries, LLC, 2011
June, 2011 − Rev. 2
1 Publication Order Number:
CAT4002A/D
CAT4002A, CAT4004A
Constant Current LED
Driver with 32 Dimming
Levels and Rset
Description
The CAT4002A and CAT4004A provide respectively two and four
matched low dropout current sources to drive LEDs. The CAT400XA
uses an external resistor RSET to set the current in the LED channels.
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 inputs supports 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 (50 mV at 20 mA) current sinks. The device is available
in the tiny 8−pad UDFN 2 mm x 2 mm package with a max height of
0.55 mm, as well as the 6−lead TSOT−23 and SC−70.
Features
• 2 and 4 LED Current Sinks with Tight Matching
• 32 Dimming Levels
• Low Dropout Driver 50 mV at 20 mA
• No Switching Noise
• Shutdown Current less than 1 mA
• LED Current set by External Resistor
• Dimming via 1−wire EZDimt Interface
• Thermal Shutdown Protection
• 6−lead TSOT−23, SC−70, and 8−pad UDFN 2 mm x 2 mm Packages
• These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
Applications
• LCD Display Backlight • Digital Still Cameras
• Cellular Phones • Handheld Devices
Figure 1. Typical Application Circuit
CAT4004A
VIN
EN/DIM
RSET
GND
LED1 LED2 LED3 LED4
RSET
3.74 kW
One wire
programming
20 mA
1 mF
2.4 V
to
5.5 V
C
IN
V
IN
http://onsemi.com
ORDERING INFORMATION
SC70−6
SD SUFFIX
CASE 419AD
TSOT23−6
TD SUFFIX
CASE 419AF
UDFN−8
HU2G SUFFIX
CASE 517AW
PIN CONNECTIONS
CAT4004A
UDFN−8
VIN
RSET
LED4
LED3
EN/DIM
GND
LED1
LED2
1
1
RSET
LED2
EN/DIM
GND
VIN
LED1
CAT4002A
TSOT23−6
1
GND
LED2
VIN
RSET
LED1
EN/DIM
CAT4002A
SC70−6
(Top Views)
See detailed ordering and shipping information in the package
dimensions section on page 11 of this data sheet.
