I'm having a bit of trouble with simulating the UCC28019. I downloaded the latest OrCad Capture and ran the simulation model from the TI site (UCC28019 transient), calculated the necessary values for the components for a 2.2kW PFC which resulted in the following schematic:
I'll put the waveforms in the next post since i can only attach one file at a time.
The original schematic was designed for 350W, I think. But the waveform that resulted is basically the same as the one i posted above. Is there any explanation for this?
Also, when i try to replace the BOOSTCCMDCM component (which I believe is the switching component) with a mosfet, it stops functioning properly (I get very low output and the PFC doesn't do it's job of correcting the source current waveform).
Maybe you can tell me about the limitations of the model...? thank you very much!
Here's the resulting waveforms:
The red line is the line current, the blue line is the inductor current, and the light blue line is the output voltage (supposedly).
Hi Danel,
A few points about the model:
1. The UCC28019 transient model is really an "Average" model that is used to test the transient features of the part. In this model, all the switching nodes have been removed and replaced with the average waveform at that node. This is required to run the simulation till ~ 2 seconds. As a result, you will not see any switching waveforms in the result.
2. The BOOSTDCMCCM block is the average model for the BOOST transistor and its interface to UCC28019 and is required for the model to function properly.
3. Startup has not been modeled in this Average Model, so please ignore the first 500ms - 1sec of the waveform as that time is required to reach the steady state.
4. The model has been tested for the 350W EVM application only. When I ram your 2.2kW application circuit, I saw distortion. However, if I reduce R23 from 30m to 20m then the distottion goes away. The result is attached below.
Let me know if this helps.
Best regards,
Nikhil
