having some problems getting it to work! I am using the 6644 ADC
and it's ev board so it just plugs straight in. The jumper (99)
is connected, the 6644 has a 5V supply and the 6620 has a 3.3V
supply. I have assumed that the other jumpers are as for the 6640
and I have checked that the PC is set up for Bi-directional operation.
My input is a 15 MHz tone at -20 dBm. The hardware does seem to
be doing something (the check bus shows some 1's and 0's) but
there is no sign of the test signal.
The AD6620 RSP input connector is directly compatible with our DRS ADC output
connectors on the AD6600, AD6640, AD6644. The AD6620 eval board jumper settings
for the AD6644 are the same as for the AD6640, which are shown in the attached
AD6620ev user manual. In addition, there are some jumper settings (J101) you
can adjust if you have timing problems. I have also attached a graphic that
shows the four possible J101 timing jumper settings.
Many customers use the AD6620 RSP eval brd/software in bypass mode to evaluate
stand-alone ADC performance. The easiest method to get a Bypass FFT is to run
the AD6644.svr script file from the AD6620 Controller Window first. This will
configure the software to collect data first in bypass mode, followed by AD6620
mode. When the script completes, go to the AD6620 Monitor Window, click the
Setup menu command to show the setup controls. In the middle, under the Data
Path group box, is a button labeled Bypass. Make sure this is selected. Then
click the Single button, and you should have the proper FFT displayed.
If you have printed any documents (even to a network printer) or used the
parallel port with any other peripherals, you may have trouble getting the eval
software to work. In this case, reboot the computer before using the eval