ADA4433 - Video Amplifier (On Evaluation Board)

Hi,

I have a ADA4433-1CP-EBZ Evaluation Board.  I have connected the board to a video source and I am evaluating the differential output of the Evaluation Board.

The ADA4433-1CP-EBZ is setup as factory default, with +IN connected to the video source, and -IN connected via a resistor divider to generate 0.5V offset.  I have connected the differential output to an AD ADA4830-1 (Differential to single ended).

My questions / Concerns are:

1.  When I connect the video signal to the +IN of the ADA4433 the video signal goes from 1V P-P to +/-0.5V P-P.  Is this correct?

2.  The differential output does not represent the negative side of the input signal, only the positive side.  Have I missed something?, can anyone please help advise what I am doing wrong?.

Attached below is the screen shot from the CRO.  The differential signal only represents the positive side of the input signal (+0.5v Peak)

Thanks.

Lok.

  • Hi Lok,

         1) Yes it is correct. With the ADA4433-1 and ADA4830-1 boards connected together the output on each leg of the ADA4433-1 will be 0.5Vp-p.

         2) You are violating the input common-mode voltage range of the ADA4433-1 which is 0V to 2.2V. Your input signal goes to -0.5V which is outside of the input voltage range.