TPS51200-EP: Simulation model for TPS51200 compatible with LTSpice

Vic Thompson

Part Number: TPS51200-EP
Other Parts Discussed in Thread: TPS51200

I need a model of the TPS1200 compatible with LTSpice.

When I downloaded the “slvm069.zip” file from: https://www.ti.com/product/TPS51200#design-tools-simulation and imported the tps51200avg.lib file into LTSpice, I ran into problems almost immediately with the error message:

Upon review of the .lib file, it appears to be encrypted, and that’s the likely reason why LTSpice shows this error message.

The reason for simulating this in LTSpice is that the TPS51200 is enabled by the Power Good from an ADI power supply, and the TPS51200’s Power Good is used to enable another ADI power supply later in the sequence. So, this design involves interaction between ADI power supplies and the TPS51200. We need to ensure there are no issues with the interaction of the ADI supplies and the TPS51200; and validate any solutions or workarounds if problems do exist.

Please provide LTSpice compatible simulation model for this part, or let me know if this is unavailable.

over 1 year ago

0 Kadeem Samuel over 1 year ago

TI__Genius 13870 points

Vic,

Do you have an NDA with TI? This is needed in order to obtain an unencrypted model.
I should note that this model is for PSpice, not directly for LTSpice.

Thanks,

Kadeem

0 Vic Thompson over 1 year ago in reply to Kadeem Samuel

Prodigy 30 points

Hi Kadeem,

Yes Fidus has an NDA with TI, signed by Paul Nolte on 9 Sep 2020. Please send unencrypted model and I will see if it works in LTSpice.

In the event it does not, perhaps you can answer the following question:

Our application has PGOOD being pulled up by an always-on power rail, and VIN applied some time later, then the TPS51200 enabled some time after that.

When the TPS51200 PGOOD pin is pulled up but VIN is not yet applied, it is understood that PGOOD will be pulled up (since the open drain output is not powered). Does the TPS51200 need to be enabled in order for PGOOD to be valid? Or is the PGOOD output correct whenever VIN is supplied?

Thanks,
VT

0 Kadeem Samuel over 1 year ago in reply to Vic Thompson

TI__Genius 13870 points

Vic,

Perfect - if you can provide your company email, I can send a model that way.

With regard to your PGOOD question, once VIN is supplied (without VLDOIN/REFIN), per the thread linked here, PGOOD should pull low. Without VIN, there is no logic powered in the device to drive the PGOOD FET low. Having said this, per the thread linked here, there is still some impedance between PGOOD and GND.

If the desired functionality is to ensure that PGOOD is never high unless the TPS51200 output is regulating, the ideal setup is to use VIN as the pullup to the PGOOD pin, with a large pullup resistance, at least 10k.

Thanks,

Kadeem