For a DAC output differential architecture, I want to evaluate the correct balun that better fits the DAC output impedance over frequency range [1; 100]MHz.
The DAC outputs drive 20mA ; it needs external 50ohm resistors to ground to provide +/-500mV DC offsets and the output swing is about 1V (into a 100ohm resistor).
However, when placing a balun (ratio 2:1) instead of the resistor, I’d like to know if the balun is correct, using either AC simulation or transient one. I use the balun S-parameter but I can see from the beginning that the DC simulation does not work with it (all is “zero”).
=> Is it possible to mix S-parameters in either AC or else transient simulations ?