1- Is it normal for the system to work without external clock?
2- We want to use external clock (30.72MHz). How can we be sure that system is working on external clock when we connect it. UG-1295 points to a setting in TES GUI (Fig 61) to enable external LO, but TES doesn't work with ZCU102. In IIOSCOPE, we could not find a relevant setting.
1. Yes, even without an external reference clock, the evaluation board will work. In AD9528 there are 2 PLL's in which the work of the first PLL is to provide a jitter free reference signal to the second PLL. Since the external reference is a reference to the first PLL, so even without this there will be VCXO ( 122.88MHz) out from the first PLL for reference to the second PLL. But there will be small drift as the first PLL is not locked.
2. Under the ADRV9009 advanced tab in the clock settings you will find the option of enabling external LO.
