My 2 cents :
1)foresee a rack mounted card to accomodate many more than 1 module
2) a 2 channel module is rather limited. Think about a 4 channel version.
3) an external clock or synchronization signal would be nice to snchonize many cards. You may think about a "master" clock or sync board for that purpose.
4) syncronization should allow 50- 100 ps jitter between boards.
5) ENOB is a key parameter.
6) You may want to integrate a low noise VGA in the input stage to accomodate for different input signal range.
7) you may consider a SMA input option.
Thanks for all these ideas! I think we're already on the same page. Expandability was a key design element from the beginning, even for the original Haasoscope.
1) The aluminum case has internal rails that the board slides into. A rack would just need to be a larger version of the case.
2) To get 4 channels, you just combine 2 haasoscope pros. They can stack on top of each other or side by side.
3) Syncing units is done through a sigle cat5 "Ethernet" cable that goes between units. The clock from the first board is replicated to downstream units.
4) The board to board jitter is at the 10-20 ps level already, limited by the Altera Pll jitter.
5) So far I've specified the same info via noise floor and input range, which seems to be more standard in the scope specs for other brands. Enob is about 10 at max sample rate, limited by the adc, but approaches 12 as the rate is lowered, thanks to sample averaging.
6) There is a vga, the lmh6401.
7) I did consider sma. They are easier, cheaper, and better bandwidth. But bnc is the standard for scopes, and we seem to be stuck with it.