The PCA9626B,118 is an I²C-bus controlled 24-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 PCA9626B,118 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 PCA9626B,118 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 need to be dimmedor blinked together without using software control.

Software programmable LED Group and three Sub Call I²C-bus addresses allow all ordefined groups of PCA9626B,118 devices to respond to a common I²C-bus address, allowing,for 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 PCA9626through the I²C-bus, identical to the Power-On Reset (POR) that initializes the registers totheir default state causing the output NAND FETs to be OFF (LED off). This allows aneasy and quick way to reconfigure all device registers to the same condition.

In addition to these features found in PCA9633, PCA9634, PCA9635, PCA9622 andPCA9624, a new feature to control LED output pattern is incorporated in the PCA9626. Anew control byte called ‘Chase Byte’ allows enabling or disabling of selective LED outputsdepending on the value of the Chase Byte. This feature greatly reduces the number ofbytes to be sent to the PCA9626B,118 when repetitive patterns need to be displayed as increating a marquee chasing effect.

If the PCA9626B,118 on-chip 100 mA NAND FETs do not provide enough current or voltage todrive the LEDs, then the PCA9634 and the PCA9635 with larger current or higher voltageexternal drivers can be used.

Feature

(Picture: Diagram)