Power Pins

The clock generator on the breakout requires 3V power. Since many customers have 5V microcontrollers like Arduino, we tossed a 3.3V regulator on the board. Its ultra-low dropout so you can power it from 3.3V-5V just fine.

Vin - this is the power pin. Since the chip uses 3 VDC, we have included a voltage regulator on board that will take 3-5VDC and safely convert it down. To power the board, give it the same power as the logic level of your microcontroller - e.g. for a 5V micro like Arduino, use 5V
GND - common ground for power and logic

I2C Pins

SCL - I2C clock pin, connect to your microcontrollers I2C clock line. This pin is level shifted so you can use 3-5V logic, and there's a 10K pullup on this pin.
SDA - I2C data pin, connect to your microcontrollers I2C data line. This pin is level shifted so you can use 3-5V logic, and there's a 10K pullup on this pin.

Clock Out Pins

0, 1, and 2 - These are the 3 independent clock generated outputs. They are square waves, from 0-3V.

The clock out pins are also brought out to SMA edge-launch connectors on the other side of the PCB. You can purchase and solder on some edge-launch SMA connectors if you want to pipe the signal into an RF cable.