Hi Enrico,
please find below the answers.
1. I want to know if it is possible to use the local oscillator internal on the AFE5809EVM card , to drive Ultrasound probes ( 8 Mhz), or if I need to use an external oscillator at 8 MHz., in CW Mode.
Yes, you can use the onboard clock to drive the 8MHz ultrasound probe in CW mode. What you need to do is just to replace the 40MHz oscillator on the top layer of the board with a 128MHz oscillator together with the 10MHz crystal on the bottom layer with a 32MHz crystal. Than making sure that C26, C25, C27, C102 are installed on the board you are supposed to get the 8MHz signal from the J10 (CLK1x).
2. Then, in the User's Guide, (SLOU338A–October 2012–Revised November 2012), at page 23, paragraph 9.3, it is not clear how to set the capacitors configuration to use External Clock for CW Mode.
Please make sure that all the capacitors listed in the Table 1 are properly configured - there's an error in the text, C154, C155, C156, C157, C49,C50,C52, and C53 are related to the AFE5808EVM.
Should you need any support please do not hesitate to contact us.
Hope it helps.
Regards,
Fabio