Pinouts

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.
This guide was first published on Aug 12, 2014. It was last updated on Oct 15, 2018. This page (Pinouts) was last updated on May 04, 2015.