7400 xtal osc
Dear all,
My supplier said the crystal I used is 3rd overtone, and they do not have the fundamental mode crystal > 30MHz.
I have tried to make the capacitors smaller(5pF), and put a parallel resistor(6.8K) to the crystal, but it still work on 13.33MHz! Could you suggest a tune method(adjust the capacitors & resistor?) to make it work properly?
I think the crystal should be OK for 40MHz, and I have to modify my design, otherwise the overtone crystals have no use? I understand that it will have no such problem if I use an oscillator instead of the crystal, but now that I encounter this problem, I would like to find it out to improve myself.
I am looking forword to your suggestions.
Best regards,
cdcll