1 Reply Latest reply on Oct 21, 2020 10:03 PM by YatheeshK_36

    CYUSB3025 Crystal Startup / Operation Problems

    kebu_4418491

      I am using a CYUSB3025 with an Epson FA-20H 19.2000MF12Y-AG3 crystal. A 100K - 1M ohm resistor across the crystal is needed to get the crystal to startup and oscillate while the SD3 is in reset. Without the resistor, it won't oscillate. When using a startup resistor, bringing the CYUSB3025 out of reset causes the oscillator to stop oscillating. 12pF caps are used for Cext on both sides of the crystal.

       

      The Epson crystal has a load capacitance value of 6pF to infinity. I am not sure what Cext should be. Does anyone have experience using an Epson FA-20H crystal with a CYUSB3025?

       

      According to Cypress lierature, the NDK NX3225SA-19.2M-EXS00A-CS03082 was used to test the FX3. I can't find this oscillator for purchase.

       

      Does anyone have a suggestion for a crystal and Cext values? I have seen examples as low as 2pF and as high as 39pF for Cext.