WEBENCH® Tools/LM43601: 1.2A output current possible?

Stefan Lintner

Expert 5165 points

Part Number: LM43601
Other Parts Discussed in Thread: LM43602, LM43603

Tool/software: WEBENCH® Design Tools

Hi Team,

I have made a design with WeBench. My design input parameters are -3V3 @ 1.2A:

WeBench comes with a result using the LM43601 chip. However this chip can maximum deliver 1 A output.

Is this an error in WeBench?

Then I tried to create a design with LM43602, because this chip is identical to the LM43601 but can deliver 2A.

However a negative voltage design seems not possible with the LM43602. What is the explanation for this?

With this chip the same inverting buck converter should be possible, what do you think?

How can we convince WeBench to create a design for a negative voltage with LM43602?

over 4 years ago

0 Frank De Stasi over 4 years ago

TI__Guru 72625 points

Hello

Yes you can use the LM43602 for an IBB. I would use the values for the LM43601 as a starting point for LM43602.

Also, your can use the inverting/non-inverting Spice model to help verify your design LM43602.

Please have a look at the attached application notes for more information.

Thanks

7673.snva856a.pdf

1832.snva722b.pdf

0 Stefan Lintner over 4 years ago in reply to Frank De Stasi

TI__Expert 5165 points

Hi Frank,

thanks for your answer!
Customer still has some questions regarding the issues he faced with WeBench:

1 – It comes with a chip of 1 A for a design of 1.2A, this should not be possible

2 – It is not possible to make a design with a negative voltage on LM43602, that is almost

identical with LM43601.

3 – If another input field is used for LM43601 or LM43602 designs with a negative voltage

can’t be used as input.

BR,
Stefan

0 Frank De Stasi over 4 years ago in reply to Stefan Lintner

TI__Guru 72625 points

Hello

These would be questions for the Webench team.

I will pass this question to that forum.

Thanks

0 Praveen Badiger over 4 years ago in reply to Frank De Stasi

TI__Expert 8365 points

Hi Stefan,

LM43601 should be created up to 1A load current only. We will fix this issue on WEBENCH. Currently, the WEBENCH model only supports the Buck topology for LM43602 and LM43603. The IBB topology is not enabled and hence it does not allow you to enter the negative output voltage.

Thanks & Regards,

Praveen

Power management

Power management forum

WEBENCH® Tools/LM43601: 1.2A output current possible?