Global Crystal Oscillator Controller

Global Crystal Oscillator Controller

Timing Functions Application

Global crystal oscillators are used to accurately synchronize multiple devices. The crystal oscillator value can be varied to match the desired frequency.



  • Any dual rail GreenPAK
  • Four resistors
  • Two capacitors
  • One crystal oscillator

GreenPAK Diagram


Design Steps

  1. Configure pins as inputs and outputs of oscillator. Feedback output must be a 1x 3-State Output.
  2. Configure logic to enable the path between the input and output of the oscillator.
  3. Connect one node of a resistor to the feedback output and the other node to the crystal oscillator.
  4. Connect the other node of the crystal oscillator to the GreenPAK’s oscillator input.
  5. Connect each capacitor on either node of the crystal oscillator. Connect the other node of both capacitors to ground.
  6. Connect resistor in between VDD and VDD2.
  7. Connect resistor in between the feedback output and the oscillator input.


GreenPAK Designer files