LM5161: Two NC pins. Is one of them to be connected as shown?

Mo Mizzi

Part Number: LM5161

Hi,

I used the Workbench to create a schematic of a buck converter, for a 10V output (with input ranging from 22V to 60V). I noticed, there are two NC pins. While one of them is not connected in the schematic, the other one is connected to the SW pin. Wanted to double check and see if it's correct. If yes, is there a way to know which NC pin is it referring to (there's one on pin# 7 and another at pin# 14).

over 1 year ago

0 Richard Fu22 over 1 year ago

TI__Mastermind 31015 points

Hi Mo,

Let me look into this and I"ll get back to you.

Thanks,

Richard

0 Richard Fu22 over 1 year ago

TI__Mastermind 31015 points

Hi Mo,

It looks like the NC pin 14 is connected to SW to optimize layout. As for the other one, it's ok to leave floating.

Thanks,

Richard

0 Mo Mizzi over 1 year ago in reply to Richard Fu22

Intellectual 290 points

Hi Richard, thank you for getting back. Is Pin 14, safe to leave it floating too?

Thank you.

0 Richard Fu22 over 1 year ago in reply to Mo Mizzi

TI__Mastermind 31015 points

Hi Mo,

I think it is better to connect pin 14 to SW just to make it easier.

Thanks,

Richard

0 Mo Mizzi over 1 year ago in reply to Richard Fu22

Intellectual 290 points

Hi Richard, thank you for getting back. Is it possible to double check this by chance? I found other reference designs using the same chip and they left pin14 floating.

Just want to make sure it doesn't run into issues after fabrication. Thank you for understanding.

+1 Richard Fu22 over 1 year ago in reply to Mo Mizzi

TI__Mastermind 31015 points

Hi Mo,

I don't think you will run into any issues with the NC pin after fabrication, since there is no connection to the pin. So I think regardless if you leave it floating or connected to SW, it is fine.

Thanks,

Richard

Power management

Power management forum

LM5161: Two NC pins. Is one of them to be connected as shown?