TINA/Spice/TPS62130: Question about AGND and ETPAD connections and effects in the TINA-TI model??

Barry Rowland

Part Number: TPS62130
Other Parts Discussed in Thread: TINA-TI

Tool/software: TINA-TI or Spice Models

Hi there TI folks;

I'm doing some simulations with a few TI SMPS parts, and I'm interested in their behaviour when connections are bad, or no-connect, or mis-connected.

I tried to run the 62130 model with AGND left 'open', and the simulator failed with some kind of convergence failure... so, I connected the AGND with a 1G Ohm resistor, to simulate a 'bad' AGND, and even isolated the ETPAD pin the same way, but the simulation showed the same behaviour as with AGND connected, and 'probing' those nodes showed a hard GND/0 V on the simulation output.

Thus, the question remains: are these 'pins' actually simulated, or just shown on the schematic for fun??

Best regards,

over 6 years ago

0 Herman Theodorus over 6 years ago

TI__Genius 9775 points

Hi Barry,

FYI, One of our team will take a look at this.

Herman

0 Saket over 6 years ago in reply to Herman Theodorus

TI__Intellectual 2680 points

Hi Barry,

The PGND, AGND and ETPAD pins are connected to 0V internally. So, that is the reason you are getting 0V in spite of 1G ohm at these pins.

In a way we can say that this device is not modeled to support any other voltage except 0V at these pins.

0 Barry Rowland over 6 years ago in reply to Saket

Intellectual 550 points

The models should be more complete, closer to real functionality... another thing of note, the models do not seem to model the ESD diode behaviour of redirecting over-voltages to Vdd or GND. I _know_ that I am doing 'unusual' things with the devices, but that is _why_ one wants to use models ;-) !

0 Barry Rowland over 6 years ago in reply to Saket

Intellectual 550 points

Does not help my investigations, but does explain it, so thanks for getting me that far :-)

0 Somen Das over 6 years ago in reply to Barry Rowland

TI__Intellectual 1040 points

Hi Barry,

Thanks for reaching out to us .If you have no more queries, we can close out this ticket.

Thanks,
Somen

0 Saket over 6 years ago in reply to Somen Das

TI__Intellectual 2680 points

Closing out this thread.

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TINA/Spice/TPS62130: Question about AGND and ETPAD connections and effects in the TINA-TI model??