I want to connect the differential signals of the I/Q outputs of the ADL5382 to another board with single-ended 50 ohms.

Hi Hirata-San,

do you need the differential-to-Single-Ended interface to be dc coupled or is ac-coupled ok? Another way to ask the question is what is the frequency range of the output signal? Is it DC to X MHz (i.e. dc-coupled) or is the range Y MHz to Z MHz? if you can clarify these questions and provide the frequency range, we can make some recommendations. Also, how much gain do you want from this stage?

Eamon

Hi Hirata-San,

take a look at AD8130 (www.analog.com/ad8130) which is a differential-in to single-ended out amplifier.  I believe that you will be able to operate it with a single supply since the ADL5382 IQ outputs have a common mode of (VPOS-2.8V). 

The AD8130 output is low impedance. So if you want to have an output resistance of 50 ohm and a system gain of  unity, then you should put a 50 ohm series resistor at the output and set the gain of the AD8130 to +2.  Lastly, if you want the singnal going to the next board to be ground-referenced, you should include a series cap (in series with the 50 ohm resistor. 

There are probably other options also but this seems like a good choice. 

Best Regards

Eamon