CAT4002A, CAT4004A
Constant Current LED
Driver with 32 Dimming
Levels and Rset
Description
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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.
UDFN−8
HU2G SUFFIX
CASE 517AW
TSOT23−6
TD SUFFIX
CASE 419AF
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.
SC70−6
SD SUFFIX
CASE 419AD
Features
• 2 and 4 LED Current Sinks with Tight Matching
• 32 Dimming Levels
PIN CONNECTIONS
1
• Low Dropout Driver 50 mV at 20 mA
• No Switching Noise
VIN
EN/DIM
GND
RSET
LED4
LED3
• Shutdown Current less than 1 mA
LED1
LED2
• LED Current set by External Resistor
• Dimming via 1−wire EZDimt Interface
• Thermal Shutdown Protection
CAT4004A
UDFN−8
• 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
1
LED1
EN/DIM
GND
VIN
RSET
LED2
Applications
• LCD Display Backlight
• Cellular Phones
• Digital Still Cameras
• Handheld Devices
CAT4002A
TSOT23−6
V
IN
1
2.4 V
to
5.5 V
20 mA
C
LED1
GND
LED2
EN/DIM
RSET
VIN
IN
1 mF
LED1 LED2 LED3 LED4
VIN
CAT4002A
SC70−6
One wire
programming
CAT4004A
EN/DIM
RSET
(Top Views)
RSET
3.74 kW
GND
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 11 of this data sheet.
Figure 1. Typical Application Circuit
© Semiconductor Components Industries, LLC, 2011
1
Publication Order Number:
June, 2011 − Rev. 2
CAT4002A/D