WEBENCH® Tools/LM3481-Q1: Values of Isense and Comp

Danilo A.

Part Number: LM3481-Q1
Other Parts Discussed in Thread: LM3481

Tool/software: WEBENCH® Design Tools

Hi Team,

A customer run a simulation of LM3481-Q1 in Webench. However, he had some concerns in the simulations as follows.

1. PIN #1 – Isen is connected to Cfilt and Rfilt resistor, but there is no equation in the datasheet or a way for finding the right values for them. (Chapter 7.3.3 in the datasheet -particularly on page 15)

2. PIN #3 – COMP is connected to an external 2 capacitors and a resistor but the datasheet document does not explain how to choose the right values for these parts.

3. When using WEBENCH, the EMI in/out filter option is greyed out. Do we have any document that will help the customer design the filter circuit?

Regards,

Danilo

over 4 years ago

0 Bhushan Waghmare over 4 years ago

TI__Expert 3320 points

Hi Danilo ,

Thanks for contacting us. For your second query you can use below literature for compensation design.

https://www.ti.com/lit/pdf/snva168

We are looking into the Webench model of LM3481 (Sepic) for your first query regarding the Cfilt and Rfilt calculations. We should be able to get back to you by mid of next week. Hope this is fine. For your third query, I will check if we can enable input EMI filter for LM3481 Sepic.

Best Regards,

Bhushan

0 Bhushan Waghmare over 4 years ago in reply to Bhushan Waghmare

TI__Expert 3320 points

Hi Danilo,

As we are continuing our discussion over the mail for these queries, I will be closing this post. Hope this is fine.

Best Regards,

Bhushan

Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

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WEBENCH® Tools/LM3481-Q1: Values of Isense and Comp