LMR33640: Method of determining parameters

Masakazu Adachi

Part Number: LMR33640

Hello team,

I received a question from the customer.

Could you please explain the calculation process for the highlighted areas?

VIN：***V，VOUT：***V，fsw：***kHz，K：***，IOUTmax：***A

For example, the following calculation results in L = 13.9uH.

where, VIN：30V，VOUT：5V，fsw：400kHz，K：0.3，IOUTmax：2.5A

Regards,

Masa

+1 Frank De Stasi over 2 years ago

Hello

The table assumes 12VIn and the full load current of the device; 4A.

You can calculate the inductance at your highest input voltage or at your typical input voltage.

However, we usually use the full load current rating of the device, rather than your maximum load current.

This will give a smaller inductor, allowing the customer to save space.

Thanks

+1 Masakazu Adachi over 2 years ago in reply to Frank De Stasi

Hello Frank,

Thanks to the support. I understand.

Regards,

Masa

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