CAT4004A_11 Datasheet, PDF (1/11 Pages) ON Semiconductor – Constant Current LED Driver

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
• Cellular Phones
• Digital Still Cameras
• Handheld Devices
V_IN
2.4 V
to
5.5 V
C_IN
1 mF
20 mA
LED1 LED2 LED3 LED4
One wire
programming
RSET
3.74 kW
VIN
EN/DIM
RSET
CAT4004A
GND
Figure 1. Typical Application Circuit
http://onsemi.com
UDFN−8
HU2G SUFFIX
CASE 517AW
TSOT23−6
TD SUFFIX
CASE 419AF
SC70−6
SD SUFFIX
CASE 419AD
PIN CONNECTIONS
1
EN/DIM
VIN
GND
RSET
LED1
LED4
LED2
LED3
CAT4004A
UDFN−8
1
EN/DIM
LED1
GND
RSET
VIN
LED2
CAT4002A
TSOT23−6
1
EN/DIM
RSET
VIN
CAT4002A
SC70−6
(Top Views)
LED1
GND
LED2
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 11 of this data sheet.
© Semiconductor Components Industries, LLC, 2011
1
June, 2011 − Rev. 2
Publication Order Number:
CAT4002A/D