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UCC5350: Model Test Circuit (UCC5350SBD_TRANS) using PSpice for TI

Part Number: UCC5350

Hi Team, 

Good day. I am posting this inquiry on behalf of the customer.

"I'm looking at using P/N UCC5350SBD as a High Side N-FET driver in a standard 14VDC automotive application. There will ultimately be two high-side N-FETs driving a 100W center-tapped audio transformer in a push-pull configuration.

I'm attempting to simulate this by starting off with the TI-supplied Model Test Circuit (UCC5350SBD_TRANS) using PSpice for TI.

The circuit as supplied in the model appears to simulate OK. But when I attempt to alter the Low Side Drive Example to a High Side Drive configuration that includes a bootstrap capacitor and diode, the output results from the load show thousands of amps as well as no signal output at the FET. The gate drive signal appears to be OK though. I don't understand what is wrong.

I'll attach the modified circuit I'm trying to use."

Please help to advise. Thank you for extending your help.

Kind regards, 

Marvin

  • Hello Marvin,

    Our expert on this device is out of office today. We should be able to reply tomorrow.

    Thanks,

    Alex M.

  • Hi Marvin,

    Your 0V "Visolation" source has shorted together your input ground and the isolated output ground. As you can see from your V(Rc) measurement, this holds the Q1 emitter at 0V and the Q1 collector at 400V. When this IGBT gate closes, there is of course a large current out of the 400V supply.

    My simulation does not converge if Visolation is deleted outright. However, I get the right results when I replace Visolation with a 10k dummy resistor. Will this be sufficient for the time being? I can try to find a way to make the model work without this dummy resistor in the meantime.

    Best regards,

    Sean