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PCA9901
One wire single LED driver
Rev. 2 — 2 September 2010
Product data sheet
1. General description
The PCA9901 is a 20 mA current source for a single LED that allows stand-alone blinking of a predefined pattern to off-load the microcontroller and save battery power.
Programming of the device is done through a training sequence: the host controller sends the LED lighting sequence and the PCA9901 memorizes it. Once the sequence has been memorized, the PCA9901 can be programmed to send it once or in a loop until the host controller requests the sequence to be stopped.
Commands and blinking sequence are sent through a uni-directional one-wire interface. Commands include: Training Start, Training End, Execute Sequence (once or in loop until a Stop Command is requested) and Reset.