Hi,
In the ADS42JBX9 EVM, there is a network of 2 resistors between the Crystek VCXO Y2 and the LMK04828:
- R138: 100 ohm, for signal attenuation.
- R44: 49.9 ohm for impedance matching.
My question is, why does R138 be equal to 100 ohm exactly?
- For Crystek VCXO, I don't know its output impedance. (If someone tell me this value, this will be helpful).
- For LMK04828, I know that for OSCin buffer: Vinl = 1.6V, Vinh = 2.0V and it is self-biased around VCM=1.039V.
Thank you.
Best Regards,
Mourad Ghorbel.