WS2801 Programmable Constant Current LED Drive IC
Preliminary WS2801 3-Channel Constant Current LED Driver With Programmable PWM Outputs

General Description
The WS2801 is a constant current LED driver. It is designed for indoor/ outdoor LED displays and decorative LED lighting system. It is suitable for LED cascading applications. The WS2801ownes 3 output channels, each channel can drive a constant current up to 30mA. WS2081 contains serial shift registers, data latches, output registers, band gap reference voltage generator, internal
Oscillator, and programmable constant output current drivers. The serial data is read into the shift registers at the rise edge of the external clock. The data and clock output buffers are designed for cascading another chip. The output polarity reverse function is designed for driving high power LED by adapting the application circuitry. The WS2801 adopts the reliable 2-wire scheme, whichfeatures low EMI transport, very strong anti-interference ability, and support hot-swap. The 2-wire control scheme can reduce the system cost; It is very suitable for low cost LED decorative LED lighting systems. WS2801 is available in both SOP-14 and DIP-14 packages, the operating temperature is -40~85° C

Features
Supports both constant voltage and constant current drive mode
Programmable constant LED drive current
Wide constant output current range 5~150mA
Build in PWM dimming scheme for each output channel,
Supports free-run, especially suitable for low cost controller
Application
PWM free-run capability(refresh rate(2.5kHz)
Build in buffers to cascading data and clock to the next driver
Output polarity reverse function
Support hot swap
Maximum input clock frequency 25MHz
Power supply voltage 3.3~5.5V

Applications
LED decorative lighting
Indoor/Outdoor LED video or massage display
PWM signal generator
LCD TV back lighting