LM2576: Inductor selection

Kazuki Itoh

Part Number: LM2576

Hello team,

My customer is trying to pick up inductor for LM2576-ADJ.

Using the formula in the D/S, they substituted Min(V) and Max(V) for Vin and Vout respectively, and calculated out the min and max values.

However, it straddles the range of H150 and L100. Could you please advise which coil should be used?

The maximum load current on the x-axis is 2.0 A.

Please find the detail from the internal link here.

Regards,

Itoh

over 4 years ago

0 J Arrigo over 4 years ago

TI__Mastermind 28020 points

Hi Itoh,

Thanks for the detailed information. According to the calculation for V*us and the inductance selection table, at max load of 2A, a 100uH inductor is recommended.

Have the customer select the 100uH inductor for this application.

Regards, Jason

0 Kazuki Itoh over 4 years ago in reply to J Arrigo

TI__Genius 10045 points

Hello Jason-san,

Thank you so much for checking!

My customer hopes to keep using 150uH inductor as they have it in the prior design.

Do you think it's OK?

Could you elaborate on why you recommend 100uH inductor?

Regards,

Itoh

0 J Arrigo over 4 years ago in reply to Kazuki Itoh

TI__Mastermind 28020 points

Hi Itoh-san,

Yes, it is OK to use 150uH for their application.

The datasheet recommends a value of inductor based on VIN, VOUT, switching frequency and load current. It recommends a value that keeps the ripple current at an appropriate level without designing for a huge inductor.

Using a slightly larger value will be ok. It will reduce ripple, but may be slower at responding to fast load.

Regards, Jason

0 Kazuki Itoh over 4 years ago in reply to J Arrigo

TI__Genius 10045 points

Hello Jason-san,

Thank you very much for your prompt support!

Regards,

Itoh

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LM2576: Inductor selection