LMR33630: Simulation does not generate the expected result.

Ramon Carreras Margalef

Part Number: LMR33630

I have simulated the LMR33630ADD using the same components as defined in the datasheet and on the evaluation board (LMR33630ADDAEVM). The only modification made was to adjust R2/R3 to achieve an output voltage of 18V in the step-down converter.

Contrary to my expectations, the output voltage is not 18V but 0V.

I have attached an image of the circuit and the simulation file.

Thank you.

LMR33630.DSN

over 1 year ago

0 Andrew Kutzler over 1 year ago

TI__Mastermind 19280 points

Hi Ramon,

I think I kind of encountered the issue you ran into, but I did get it to work.

I downloaded this file:

I used the default circuit, but I changed FASTSS to 1 and your FB network.

Here you can see the VOUT converging to 18V.

I think it may have to do with the simulation profile. I did run into issues when I changed the step size.

Thanks,

Andrew

0 Ramon Carreras Margalef over 1 year ago in reply to Andrew Kutzler

Prodigy 20 points

Changing FASTSS to 1 and setting the maximum Step Size to 20ns, the simulation runs very slowly, but we obtain an output of 18V. So, my simulation works well with this configuration.

Thank you.

Simulation, hardware & system design tools

Simulation, hardware & system design tools forum

LMR33630: Simulation does not generate the expected result.