Have any AD7708 sample code or initial code availabe on Website?
I got some AD7708 samples and hardwire component in my PCB.
I found the Crystal is work strange. there is only waveform on pin 27(XTAL 2), but pin 28(XTAL 1) has no any waveoform.
is it correct or not?
I had double checked data sheet, but I can't find what's going on this problem.
I attached my connection and waveform for your reference.
Thank you very much.
It is hard to identify whether a crystal oscillator is working properly by scoping it. It is because, the leads on the scope could introduce extra capacitance to your oscillator circuit therefore giving you an inaccurate data.
The best way to know whether a crystal oscillator is working is to monitor the RDY output of the AD7708 and check its frequency. If the frequency of the output corresponds to what is expected, then the crystal is working. If not, It is recommended to check the values of the capacitors. Make sure that the values of the capacitors (including pin capacitance of approximately 10pF) are within the specs of the Crystal Oscillator.
Thanks and Best Regards,