UCC28C42

Petuker,

I have a couple of questions.

First, why are you using the steady state model? Most of the time, the steady state model is used if you know what your inputs and outputs are expected and you pre-condition the nodes to the proper currents and voltages so that the model will skip the startup and immediately go into regulation. You have not used any initial conditions.

Second, could you tell me what your operating conditions are? Vin, Vout (expected), etc. How was the circuit derived?

Your VIN is set at DC 12V and an additional 1V unit step currently.

For a new design, I would recommend using the startup model (the reference design is in the EXAMPLES/Smps/UCC28C42 directory built into TINA-TI. Start with it and modify it to your design. Once you have the startup circuit working, you can see what the voltage values needed to set the initial conditions for the steady state simulation would be. You can also verify your design is functioning.