TPS62120: Inductor Quality factor

Emil Bonnevie

Part Number: TPS62120
Other Parts Discussed in Thread: TPS62122

Hey TI

In the datasheet for TPS62120/2 under inductor selection it is recommended/warned that the design uses an inductor with a quality factor of less than 25. Then it proceeds to recommend Murata LQH3NPN which in SimSurf checks out with ~50 quality factor at F_sw.

So do you recommend going for a high Q as long as stability is robust? Or play safe and inefficient with lower Q inductors?

On a side note: I am a bit unsure about choosing TPS62120 or TPS62122. I am mostly concerned about price and have no size constraint. I do not suppose I will gain much from the reduced thermal resistance. Will I gain anything on the EMI front perhaps?

Regards

Emil Bonnevie

over 5 years ago

0 Jason Wang (BSR-MV) over 5 years ago

TI__Genius 9550 points

hi,

We are looking into your question and will give you feedback on Monday.

0 Sam(MPAA) Zhang over 5 years ago

TI__Mastermind 19080 points

Hi Emil,

I think it's OK to use a high-Q inductor here.

1K prices are the same with two devices. From thermal perspective, TPS62120 would be better, as the RthetaJA is smaller due to its thermal pad. For EMI performace, it should be similar as long as the input loop area is kept smallest.

Thanks!

Regards,

Hao

Power management

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TPS62120: Inductor Quality factor