Thermal power dissipation- Buck and Inductor

Vignesh M26

Hi TI Team,

For calculating the device power loss, Do we really need to subtract the Inductor DCR power loss from buck regulator power loss? So regulator efficiency inherently combined with the DCR power loss of Inductor? Please clarify on the below,

Thanks,

Vignesh.M

over 4 years ago

0 JohnTucker over 4 years ago

TI__Guru**** 191445 points

Vignesh,

Yes you should subtract the inductor loss. There are other losses as well such as RMS ripple losses in the capacitors and IR losses in the FB resistors, but they are small compared to the inductor and IC losses. You can also use the on line Webench tool. It will calculate the individual power losses for you .

0 Vignesh M26 over 4 years ago in reply to JohnTucker

Intellectual 590 points

Thanks,

But What I thought was the regulator efficiency is drawn for only concidering the losses on inductor regulator only (such regulators MOSFET switching (Qg), conduction Rds(on) and comparator bias current loss, etc) like that.

Now understood that the efficiency plot which we calculate loss is for whole power systems, ie, including inductor and capacitor losses..

Please confirm my understanding is correct..

Regards,

Vignesh.M

0 Yuchang Zhang over 4 years ago in reply to Vignesh M26

TI__Mastermind 18510 points

Vignesh, Yes, the Loss related to efficiency should include be total system loss, include caps, inductor, converter bias current, FET switching and conduction loss...

Yuchang

0 Vignesh M26 over 4 years ago in reply to Yuchang Zhang

Intellectual 590 points

Thanks John Tucker & Yuchang..

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Thermal power dissipation- Buck and Inductor