LM5145-Q1: LM5145-Q1 Pspice Model issue

Shanjai kanna S

Part Number: LM5145-Q1

Dear Support Team,

During simulation, we observed an issue related to the VCC external bias functionality. In our design, VOUT (12 V) is connected to the VCC pin through a diode, and this functionality works correctly during real-time testing on the evaluation board. However, in the PSpice simulation environment, the VCC pin does not switch to the 12V output voltage as expected.

I am attaching the PSpice model which we are using. Could you please verify whether this functionality is supported in the current PSpice model? Additionally, do you have any updated/latest PSpice model for the LM5145-Q1 that includes or better supports the external bias functionality for verification?snvmb65c.zip

We appreciate your support and look forward to your feedback.

1 month ago

0 Onkar Bhakare 1 month ago

TI__Mastermind 27412 points

Hello Shanjai

We'll take look and get back to you in day or 2

Thank you

Regards

Onkar Bhakare

0 Shanjai kanna S 1 month ago in reply to Onkar Bhakare

Prodigy 30 points

Hello Onkar,

Thank you for your reply. Awaiting your prompt response.

Thanks,

Shanjai Kanna S

0 Sourish Nandy 1 month ago in reply to Shanjai kanna S

TI__Genius 13120 points

Hello Shanjai,

Let me check the your model and the model internally to find any discrepancy.

Regards,

Sourish

0 Sourish Nandy 1 month ago in reply to Sourish Nandy

TI__Genius 13120 points

Hello Shanjai,

The model is internally hard clamped to always have VCC of 7.5V. Even if you try to pull it up to any other voltage, it will still have VCC of 7.5V only.

What do you exactly want to verify in Pspice simulation by pulling the VCC to to Vout?

Regards,

Sourish

0 Shanjai kanna S 1 month ago in reply to Sourish Nandy

Prodigy 30 points

Hello Sourish,

Our design intent is to drive two parallel MOSFETs by applying external bias supply. For External bias, we are connecting same DC-DC Converter VOUT (12V) to VCC pin using a diode to drive the parallel MOSFETs as 12V (Gate to Source Voltage) for both high side and low side. We need verify whether we able to drive the parallel MOSFETs (as VGS voltage) without any cross conduction between high side and low side, with 12V external bias instead of internal 7.5V bias voltage. Please refer the below image.