DRV8843 power dissipation

Gilad Indig

Prodigy 30 points

Other Parts Discussed in Thread: DRV8843

I need to know what is the internal LDO maximum output current during switching with 16KHz & 32KHz.

this is not mentioned in the datasheet

It seems that beside the Vm*Ivm, Rds(on) and drive current factors, I get more 400mW power consumption under Vm of 18V.

over 12 years ago

0 Jose Quinones over 12 years ago

TI__Expert 7455 points

Hi Gilad,

The following application note details all the forms of power dissipation you will encounter when using the great majority of our drivers: http://www.ti.com/general/docs/lit/getliterature.tsp?literatureNumber=slva504&fileType=pdf

The 400 mW extra power consumption you refer to must come from the switching losses. When you say you are getting 400 mW more at 18V, this is compared to what? 12V? Overall, switching losses will always increase with VM as well as with frequency.

Hope the info helps. Best regards,

Jose Quinones

0 Gilad Indig over 12 years ago in reply to Jose Quinones

Prodigy 30 points

hi Jose,

thanks for your response.

i know this document.

after taking in account the following:

1. Vm*Ivm

2. 4*Rds(on)*Iout^2

3. Psw

I still have "unexplained" 400mW.

according to the linked document (section 1.4) the only thing left is the LDO power.

Ufortunately the information about Ildo_out is missing in the DRV8843 datasheet.

Thanks!

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DRV8843 power dissipation