16-Channel 12-bit PWM/Servo Driver - I2C PCA9685 (Adafruit 815)

• It's an i2c-controlled PWM driver with a built in clock. That means that, unlike the TLC5940 family, you do not need to continuously send it signal tying up your microcontroller, its completely free running!
• It is 5V compliant, which means you can control it from a 3.3V microcontroller and still safely drive up to 6V outputs (this is good for when you want to control white or blue LEDs with 3.4+ forward voltages)
• 6 address select pins so you can wire up to 62 of these on a single i2c bus, a total of 992 outputs - that's a lot of servos or LEDs
• Adjustable frequency PWM up to about 1.6 KHz
• 12-bit resolution for each output - for servos, that means about 4us resolution at 60Hz update rate
• Configurable push-pull or open-drain output
• Output enable pin to quickly disable all the outputs

• Terminal block for power input (or you can use the 0.1" breakouts on the side)
• Reverse polarity protection on the terminal block input
• Green power-good LED
• 3 pin connectors in groups of 4 so you can plug in 16 servos at once (Servo plugs are slightly wider than 0.1" so you can only stack 4 next to each other on 0.1" header
• "Chain-able" design
• A spot to place a big capacitor on the V+ line (in case you need it)
• 220 ohm series resistors on all the output lines to protect them, and to make driving LEDs trivial
• Solder jumpers for the 6 address select pins

• Dimensions (no headers or terminal block) 2.5" x 1" x 0.1" (62.5mm x 25.4mm x 3mm) 
• Weight (no headers or terminal block): 5.5grams 
• Weight (with 3x4 headers & terminal block): 9grams

• Datasheet PCA9685