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I'm working with a high quality ADC that needs a low jitter, low noise clock source. My question is: what are the specs of the internal 50MHz oscillator of the DE1-SOC? I'm looking for crystal oscillators with < 2ps rms jitter, and < 5 ns rise/fall time. Will the internal clock meet these requirements?
If I choose to use an external clock, will it be an issue to clock the FPGA off of it?
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Hi there
There are some variations in the internal oscillator frequency because of the process, voltage, and temperature (PVT) conditions.
If you need a precise frequency for operation you must use an external reference such as a crystal oscillator based device or a known accurate frequency source.
Thanks.
Eng Wei
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Thanks for the reply. Isn't that the case for any oscillator? A datasheet would normally list the frequency variation, jitter, phase noise, etc., where can I find the datasheet for the oscillator inside the DE1-SOC?
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Hi there
The drift is per device basis. There is no specification published on how much it will drift across PVT (process, voltage, temperature). But it would not fit for accuracy requirement.
Thanks.
Eng Wei
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Hi there
Since there is not further question on this topic, I am transferring this thread to community support. If you have a new question, feel free to open a new thread to get the support from Intel experts. Otherwise, the community users will continue to help you on this thread. Thank you.
Eng Wei

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