LM5122: FET selection

min kyung jin

Part Number: LM5122
Other Parts Discussed in Thread: CSD17309Q3, CSD18543Q3A

Hi team,

I am doing LM5122 simulation using WEBENCH. The WEBENCH link is here:

I’d like to ask your help about FETs.

Webench chose CSD17309Q3 for M1 and CSD17575 for M2, but we are considering change M1, M2 FETs to CSD18543Q3A.

Because It is same package and Vds 60V. and our system need operation in wide-input voltage.

Is it possible? If not, please recommend FETs.

our system requirement is below:

- Input Voltage range :8~60V

- Normal Operation voltage : 9~28V

- Vout : 22V

- Iout : ~10A

thanks

0 Yinsong Cai1 over 2 years ago

Thank you for choosing LM5122.

To fully understand your case, is it going to operate in bypass when Vin>=22V?

Thanks,

Yinsong

0 min kyung jin over 2 years ago in reply to Yinsong Cai1

Yes. If Vin >= 22V, we want operate in bypass mode.

thanks

0 Yinsong Cai1 over 2 years ago in reply to min kyung jin

Thank you for the confirmation. The MOSFETs are ok but you may want to double check their power dissipation.

Thanks,

Yinsong

0 min kyung jin over 2 years ago in reply to Yinsong Cai1

thank you for your review.

thanks

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