Image of the B output stage of the EVAL-CN0304 AD9834 DDS Evaluation Board
IOUT_B is a current source, not potential source, so the initial say half of the circuit I get. The resistor gives us a proportional voltage, where it is centred on the input range + put through a unity gain amplifier, so we do not load down the input + cause issues. What I don't get then is why it is put through this 51 ohm voltage divider and all these capacitors and inductors. It seems like this would create a bunch of nasty resonant peaks from the LC oscillators.