3-Channel Constant-Current RGB LED Driver
Description
The CAT4103 is a 3−channel, linear based constant−current LED
driver designed for RGB LED control, requiring no inductor and
provides a low noise operation. LED channel currents up to 175mA
are programmed independently via separate external resistors. Low
output voltage operation of 0.4 V at 175 mA allows for more power
efficient designs across wider supply voltage range. The three LED
pins are compatible with high voltage up to 25 V supporting
applications with long strings of LEDs.
A high−speed 4−wire 25 MHz serial interface controls each
individual channel using a shift register and latch configuration.
Output data pins allow multiple devices to be cascaded and
programmed via one serial interface with no need for external drivers
or timing considerations. The device also includes a blanking control
pin (BIN) 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 whenever the die temperature exceeds 150°C.
The device is available in a 16−lead SOIC package.

Features
• 3 Independent Current Sinks Rated to 25 V
• LED Current to 175 mA per Channel Set by Separate External
Resistors
• High−speed 25 MHz 4−wire Serial Interface
• Buffered Output Drivers to Ensure Data Integrity
• Cascadable Devices
• Low Dropout Current Source (0.4 V at 175 mA)
• 3 V to 5.5 V Logic Supply
• Thermal Shutdown Protection
• 16−lead SOIC Package
• These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
Applications
• Multi−color, Intelligent LED, Architectural Lighting
• High−visual Impact LED Signs and Displays
• LCD Backlight