LM25149-Q1: PSpice Simulation Troubles

Jackson Carmichael

Intellectual 840 points

Part Number: LM25149-Q1

Hello,

I'm trying to replicate this WeBench circuit in PSpice, but am encountering errors. Here is the Webench circuit:

Here is the PSpice layout:

Here is the error when I try to run the simulation (N04654 is the wire from CNFG to the resistor):

Do you have any advice where I'm going wrong?

Also, I think there is sometimes a way to export the Webench design into PSpice directly, but that was not available with this circuit.

Thank you for your help!

over 2 years ago

0 Orlando Murray over 2 years ago

TI__Mastermind 22299 points

Jackson,

Can you find whats the node N04654? You can use CTRL+F to find the node.

-Orlando

0 Jackson Carmichael over 2 years ago in reply to Orlando Murray

TI__Intellectual 840 points

I believe it is the wire between the R6 resistor and the CNFG pin.

+1 Orlando Murray over 2 years ago in reply to Jackson Carmichael

TI__Mastermind 22299 points

Hi Jackson,

I see, this looks like an issue with the model, go ahead and delete the resistor and leave CNFG floating to get the sim running.

This model does not do dual-phase or spread-spectrum, so it essentially can only model RCNFG = 24.9k. Leave CNFG floating in the PSPICE model as that's how the default model is shipped.

Of course on the actual board dont leave CNFG floating.

I'll see about getting the model updated.

-Orlando

+1 Orlando Murray over 2 years ago in reply to Orlando Murray

TI__Mastermind 22299 points

Also, I looked at the default Steady-state schematic, the CNFG is tied to GND and this simulation is able to run.

CNFG to GND is a valid connection, it is the same mode as RCNFG = 24.9k.

Hope this helps,

-Orlando

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LM25149-Q1: PSpice Simulation Troubles