LED controller optimised for LCD backlighting

The PCA9685 is an I²C, 16-channel LED controller optimised for LCD Red/Green/Blue/Amber (RGBA) colour backlighting applications.

Each LED output has its own 12-bit resolution fixed-frequency PWM controller. This operates from a typical programmable frequency of 40Hz to 1000Hz with a duty cycle that is adjustable from 0% to 100%, allowing the LED to be set to a specific brightness value.

The PCA9685 12-bit PWM enables 4096 steps of individual LED-brightness control, and the 40Hz to 1000Hz programmable frequency allows the use of external power-supply controllers.

LEDs can be directly connected to the LED output (up to 25mA, 5.5V) or controlled with external drivers and a minimum amount of discrete components for larger-current or higher-voltage LEDs. The PCA9685 also allows staggered on and off times for the LED output to minimise current surges. An external Clock Input pin accepts a user-supplied clock to enable synchronisation of multiple devices.

The PCA9685 is in the new Fast-mode Plus (Fm+) family. Fm+ devices offer higher frequency of up to 1MHz and more densely-populated bus operation, up to 4000pF. Six hardware-address pins allow up to 62 devices on the same bus.

Software-programmable LED All Call and three Sub Call I²C-bus addresses allow all or defined groups of PCA9685 devices to respond to a common I²C-bus address, minimising I²C-bus commands.

 

FEATURES 16 LED drivers Programmable LED brightness Programmable LED turn-on time to help reduce EMI Software-reset feature 25MHz typical internal oscillator requires no external components External 50MHz (max.) clock input Noise filter on SDA/SCL inputs Supports hot insertion Low standby current Voltage range: 2.3V to 5.5V 5.5V tolerant inputs Package options: TSSOP28, HVQFN28

APPLICATIONS Colour mixing/dimming Architectural lighting LCD backlighting RGB or RGBA LED drivers LED status information LED displays Keypad backlights for handheld devices

 

 

NXP Semiconductors / PCA9685