Hi Joel,
I have designed the board based on evaluation board and testing it. So the signal level is given is based on my custom board.Both VGAs are working independently but i am facing problem when it is in cascading thats why i am not getting full gain from second stage VGA. It may be due to impedance mismatch or feltering requirement. So I have following points need to be cleared from you.
- If we use 10 dB pad(T/Pi network) between VGA1 and VGA2 what should be its input and output impedance? will it be 50 or 200 ohm.
- If we use 50 ohm band pass filter having loss of 10dB,Do we still need impedance match or can we avoid impedance match? We prefer without impedance match.
Which of the above option will be better?
Do the output of VGA2 can drive directly 50 ohm load without impedance matching network/L-pad? If no please suggest network.
Regards
J S Hyanki