I am using an ADV7611 HDMI receiver and the output bus is connected to a ADV7125 DAC. Unfortunately the ADV7125 will not interface with the differential IQ lines to my ADL5375 modulator.
May I substitute an AD9785 or a AD9776A for the ADV7125? I want to get my pixel data from the ADV7611 into a DAC that will allow me to connect to the IQ lines of my modulator.
Depending on your application, could you perhaps use a mixer to upconvert the RGB data?
If you have to use the ADL5375, as edo mentioned, the I and Q inputs need to be in quadrature phase - 90 degrees…
If you have to use the ADL5375, as edo mentioned, the I and Q inputs need to be in quadrature phase - 90 degrees apart, to get a single-side band output. Also, please keep in mind that the required common mode voltages on the ADL5375 is 0.5V for the ADL5375-05 and 1.5V for the ADL5375-15. Looking at the ADV7125 datasheet, it looks like the full scale current output can be adjusted by Rset. If Rset is set to 20mA, then it will set 0.5V with 50 ohm on source termination on ADV7125. Then it can interface to ADL5375-05 directly.
Please refer to "DAC MODULATOR INTERFACING" SECTION on page 24 of ADL5375 Datasheet.