Tool/software: TINA-TI or Spice Models
Hi Team,
I'm running an AC Transfer Characteristic in Tina TI for a simplified LLC circuit (see below). The input is Vin1 (red circle) and the output is AM1 (blue circle). I run the AC Transfer Characteristic and end up with a graph (also below) showing gain (dB) vs frequency. Is this gain a ratio of input voltage to output current or input current to output current? Or something else?
Thanks,
-Sam
This was resolved offline. The resolution is posted below:
If you are just trying to simulate the output filter, I would recommend the following:
Apply the Average voltage that you expect to see to the Capacitor C1 (DC value) + excite this with an AC signal. You should not put in the switches (the reason being that the simulator will try to calculate the bias point first before running the AC sim and since one switch is on and one is off, it will take the voltage on C1 pin as either 400V or 0V which will give incorrect bias point.
By averaging the waveform that you would see on that node and applying it directly, it will give you proper results. Also, do a quick check of the DC bias points on the circuit nodes to make sure they are giving expected results. For example, right now you are getting 0V on Vout which is not the right steady state bias point.
