he PCA9685 is a 16-channel I2C-bus controlled LED controller optimized for Red/Green/Blue/Amber (RGBA) color backlighting applications. Each LED output has individual 12-bit resolution (4096 steps) PWM controller with a fixed frequency. The controller operates at a programmable frequency from a typical 24 Hz to 1526 Hz with a duty cycle that is adjustable from 0% to 100% so the LED can be set to output a specific brightness. All outputs are set to the same PWM frequency.
With the PCA9685 as the master chip, the 16-channel 12-bit PWM Servo Driver only needs 2 pins to control 16 servos, thus greatly reducing the occupant I/Os. Moreover, it can be connected to 62 driver boards at most in a cascade way, which means it will be able to control 992 servos in total.
1. Contains an I2C-controlled PWM driver with a built-in clock. It means, unlike the TLC5940 family, you do not need to continuously send it signals tying up your microcontroller; it’s completely free running!
2. 5V compliant, which means you can control it from a 3.3V microcontroller and still safely drive up to 6V outputs, which is good when you want to control white or blue LEDs with a 3.4V+ forward voltage
3. Supports using only two pins to control 16 free-running PWM outputs – you can even chain up 62 breakouts to control up to 992 PWM outputs.
4. 3 pin connectors in 4 groups, so you can plug in 16 servos at one time (Servo plugs are slightly wider than 0.1″ so you can only stack 4 adjacent ones on 0.1″-hole female headers.
5. 12-bit resolution for each output – for servos, that means about 4us resolution at an update rate of 60Hz.
6. Size: 62 x 26 mm