PCA9685 16-CHANNEL,12-BIT PWM FM+ I2C-BUS LED CONTROLLER

The PCA9685 is an I2C-bus controlled 16-channel LED controller optimized for Red/Green/Blue/Amber (RGBA) color backlighting applications. Each LED output has its own 12-bit resolution (4096 steps) fixed frequency individual PWM controller that operates at a programmable frequency from a typical of 24 Hz to 1526 Hz with a duty cycle that is adjustable from 0 to 100 to allow the LED to be set to a specific brightness value. All outputs are set to the same PWM frequency.

Each LED output can be off or on (no PWM control) or set at its individual PWM controller value. The LED output driver is programmed to be either open-drain with a 25 mA current sink capability at 5 V or totem pole with a 25 mA sink, 10 mA source capability at 5 V. The PCA9685 operates with a supply voltage range of 2.3 V to 5.5 V and the inputs and outputs are 5.5 V tolerant. LEDs can be directly connected to the LED output (up to 25 mA, 5.5 V) or controlled with external drivers and a minimum amount of discrete components for larger current or higher voltage LEDs.

PCA9685 FEATURES

  • 16 LED drivers. Each output programmable at:
    • Off
    • On
    • Programmable LED brightness
    • Programmable LED turn-on time to help reduce EMI
  • 1 MHz Fast-mode Plus compatible I²C-bus interface with 30 mA high drive capability on SDA output for driving high capacitive buses
  • 4096-step (12-bit) linear programmable brightness per LED output varying from fully off (default) to maximum brightness
  • LED output frequency (all LEDs) typically varies from 24 Hz to 1526 Hz (Default of 1Eh in PRE_SCALE register results in a 200 Hz refresh rate with oscillator clock of 25 MHz)
  • Sixteen totem pole outputs (sink 25 mA and source 10 mA at 5 V) with software programmable open-drain LED outputs selection (default at totem pole). No input function

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