PCA9901 Overview
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.
PCA9901 Key Features
- 1 wire interface to control the device
- Stand-alone blinking capability while training the sequence to blink
- Sequence includes up to 3 blinking elements
- 12-bit (4096 steps) LED ON and OFF timings for each blinking element
- 1.8 V pliant one-wire logic interface
- Training Start, Training End, Run-Once, Run, Stop and Reset mands
- High side current controlled LED driver with 1 mA to 20 mA max current in the LED set by an external resistor. 5 mA driv
- 110 mV max dropout voltage driver at 20 mA
- Fully internal oscillator for sequence training, LED timing, mand and Sequencing Controls
- Short circuit and thermal protection