[Discuss-gnuradio] USRP Design and Power Q's

[COMINT]

Hi Matt/Eric

I have a few questions I need some help on.....

Firstly, I am trying to understand the power supply nets.

There is:

DVDD (GND) [Digital Supply and Unnamed Ground Symbol]
VCC 5:1  (Ground unkown?)
AVDD (AGND)  [Analogue Supply and Ground]
AVDD 2:1  (AGND 2:1)  (??)
5V:1 (??)

I can see the voltages coming from the power supply jack as feeding 5V:1 before input, and DVDD after output....so does that mean they have effectively the same grounding NET?

As for the others I'm a little lost.....  

There is a component marked VCTCXO yet I cannot seem to identify this component and there is nothing more on the BOM. Does anyone have a part number? What does it do?

The LINEAR LT1085 Voltage Regulator...have I identified the correct component here?
http://ie.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=573358&N=401

J1001 appears to not be linked to anything on the schem except for ground? Does this header have a purpose? Some sort of grounding safety...?

F501....fuse? Is there anything there, on the board it looks "NONE"...! If it should be present does anyone have a part number?


Ok I think that is enough questions for now...! I'm about half way done on the conversion so once I define the power nets properly I should be 80% done with the Protel designs.

Thanks again for all the help!

Kind regards

Mochara



PS. One last one! Once a board is assembled how do you program the FPGA eeprom? Can you program it on board via the USB or do you need an on board header connection? Or is it programmed pre-placement?