PCA9531PW,112

The PCA9531PW,112 is a 8-bit I?C-bus LED Dimmer optimized for dimming LEDs in 256 discrete steps for red, green and blue (RGB) colour mixing and back light applications. The LED dimmer contains an internal oscillator with two user programmable blink rates and duty cycles coupled to the output PWM. The LED brightness is controlled by setting the blink rate high enough (>100Hz) that the blinking cannot be seen and then using the duty cycle to vary the amount of time the LED is on and thus the average current through the LED. To blink LEDs at periods greater than 1.69second the bus master must send repeated commands to turn the LED on and off as is currently done when using normal I/O expanders like the semiconductors.