I am working on a radio project in my spare time. The proposed
architecture will use an LT5506 to bring a signal down to baseband,
through some low-pass filters, then into a DSP chip for all the 'real'
processing. I'd like to prototype this thing in pieces before I put it
all onto one tiny board. So I have some questions for the group:

LT5506, 40-500MHz I/Q demodulator with built-in VGA

Have you ever used it?

Do you know if there's an eval board available (Linear doesn't appear to
have anything, but I may not be navigating their site correctly).

Do you know of any alternatives? Something that had built-in low-pass
filters would be tres cool.

Data Acquisition:

I'd like to buy (or build, if I have to) an eval board for the LT5506
and acquire chunks of data to feed to a PC. For this I'd need a data
acquisition device that could sample two channels at no less than 10kHz;
50kHz would be nicer; 16 bits would be nice but I could live with 12
(for 8 bits or less I can use my 'scope). I've found one that's $400 or
so for analog in/USB out -- is that the best I can do? Any suggestions
will be appreciated.

Low-Pass Filters:

My thinking right now is that I'll just come out of the LT5506 into
passive RC filters, oversample the snot out of the signals, and do a
quickie filter-and-decimate before I do the complex signal processing.
Anyone know of a really small low-pass filter I could use that would
have better performance? The LT5506, naturally, has balanced outputs
and its specifications go to hell if you don't use them as such, so any
solution will have to accept a balanced input.

Thanks all.

--
Tim Wescott
Wescott Design Services
Voice: 503-631-7815
Cell: 503-349-8432
http://www.wescottdesign.com