Fox Electronics recommends a 4-layer PCB with a solid ground plane, and a separate power plane for the oscillator circuit. Additionally, keep the oscillator circuit away from noisy digital signals and ensure a low-impedance path for the crystal oscillator.
To ensure reliable startup, Fox Electronics recommends using a 1-2 kΩ resistor in series with the crystal, and a 10-22 pF capacitor in parallel with the crystal. Additionally, ensure the power supply is clean and stable, and the PCB layout is optimized for low noise.
The FE250F-20 is designed to operate within ±50 ppm of the specified frequency. However, Fox Electronics recommends limiting the frequency deviation to ±20 ppm to ensure optimal performance and minimize potential issues with clock synchronization.
While the FE250F-20 is rated for operation up to 85°C, Fox Electronics recommends derating the frequency by 0.05% per degree Celsius above 70°C to ensure reliable operation. Additionally, ensure the PCB and surrounding components are designed for high-temperature operation.
To troubleshoot oscillator startup issues, Fox Electronics recommends checking the power supply voltage, ensuring the crystal is properly connected, and verifying the PCB layout is correct. Additionally, use an oscilloscope to check for any signs of oscillation, and consult the application notes for further guidance.
