TINA/Spice/TPS54331: Is it suitable as inverting Buck-Boost?

Günter Thelen-Piazzolla

Part Number: TPS54331
Other Parts Discussed in Thread: TINA-TI,

Tool/software: TINA-TI or Spice Models

Hello Ti,

I have been trying to adapt your AppNote on inverting Buck-Boost usage (SLVA317B) to the TPS54331, with Vin=5V and several Vouts from -5V to -20V, but simulating in Tina-Ti always leads to an output Voltage of -90V, regardless what I change. I tried with the models from the Tina-Ti lib and the model from Slim041a.tsc.

Is this a limitation of the device or is it a limitation of the device model?

I know there are better suited devices for this case but I wanted to reuse parts from our running production just for a few builds...

Thank you in advance,

Guenter

over 7 years ago

0 Milo Zhu over 7 years ago

TI__Intellectual 2795 points

-90V already exceed the TPS54331 abs voltage, so this should be model limiation.

0 Günter Thelen-Piazzolla over 7 years ago in reply to Milo Zhu

Prodigy 120 points

Okay, understood.

But the question was more like 'Does it burn up in RL like it does in the simulation, or is the model not suitable in an inverting buck-boost setup?'

I guess I will give it a try next week, if it burns I'll post a photo :)

Thank you,

Guenter.

0 Shawn Nie over 7 years ago in reply to Günter Thelen-Piazzolla

TI__Genius 10070 points

Hi Guenter,

How is the test result? Please let us know after you try it.

Best Regards,
Shawn Nie

0 Günter Thelen-Piazzolla over 7 years ago in reply to Shawn Nie

Prodigy 120 points

Okay,

I did a quick and dirty test with our 24V -> 12V @ 2A converter boards. I just applied 5 Volts between 24Vin and 12Vout and got promising -12V at the ground pin of the original setup. (I did not adjust anything)

With a load of 65mA @ 12V out the circuit took 165mA @ 5V input. soldering two 22uF X7R caps from input to the 'new ground potential' lead to a ripple of 350mV at the input.

So, yes I would say the device works in this setup, just have to tune it now.

Thank you,

Guenter.

0 Shawn Nie over 7 years ago in reply to Günter Thelen-Piazzolla

TI__Genius 10070 points

Sounds good, good luck.

Best Regards,
Shawn Nie

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TINA/Spice/TPS54331: Is it suitable as inverting Buck-Boost?