PCA9624PW,112

PCA9624PW,112 1. General description

The PCA9624 is an I2C-bus controlled 8-bit LED driver optimized for voltage switchdimming and blinking 100 mA Red/Green/Blue/Amber (RGBA) LEDs. Each LED outputhas its own 8-bit resolution (256 steps) fixed frequency individual PWM controller thatoperates at 97 kHz with a duty cycle that is adjustable from 0 % to 99.6 % to allow theLED to be set to a specific brightness value. An additional 8-bit resolution (256 steps)group PWM controller has both a fixed frequency of 190 Hz and an adjustable frequencybetween 24 Hz to once every 10.73 seconds with a duty cycle that is adjustable from 0 %to 99.6 % that is used to either dim or blink all LEDs with the same value.Each LED output can be off, on (no PWM control), set at its individual PWM controllervalue or at both individual and group PWM controller values. The PCA9624 operates witha supply voltage range of 2.3 V to 5.5 V and the 100 mA open-drain outputs allowvoltages up to 40 V.The PCA9624 is one of the first LED controller devices in a new Fast-mode Plus (Fm+)family. Fm+ devices offer higher frequency (up to 1 MHz) and more densely populatedbus operation (up to 4000 pF).The active LOW Output Enable input pin (OE) blinks all the LED outputs and can be usedto externally PWM the outputs, which is useful when multiple devices must be dimmed orblinked together without using software control.Software programmable LED Group and three Sub Call I2C-bus addresses allow all ordefined groups of PCA9624 devices to respond to a common I2C-bus address, allowingfor example, all red LEDs to be turned on or off at the same time or marquee chasingeffect, thus minimizing I2C-bus commands. Seven hardware address pins allow up to126 devices on the same bus.The Software Reset (SWRST) Call allows the master to perform a reset of the PCA9624through the I2C-bus, identical to the Power-On Reset (POR) that initializes the registers totheir default state causing the outputs to be set HIGH (LED off). This allows an easy andquick way to reconfigure all device registers to the same condition.The PCA9624 and PCA9634 software is identical and if the PCA9624 on-chip 100 mANAND FETs do not provide enough current or voltage to drive the LEDs, then thePCA9634 with larger current or higher voltage external drivers can be used.

PCA9624PW,112 2. Features and benefits

PCA9624PW,112 3. Applications