TPD1S514: How to calculate the total loss inside the device with FET current pass

Shinichi Inoue

Guru 21676 points

Part Number: TPD1S514

Tool/software:

Dear Specialists,

My customer is considering TPD1S514 and has a question.

I would be grateful if you could advise.

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I think the total loss of the TPD1S514 needs to take into account not only its own current consumption, but also the loss of the VBUS current passing through it.

Could you please let us how to calculate the total loss inside the device.

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I appreciate your great help in advance.

Best Regards,

Shinichi

10 months ago

+1 Eric Hartigan 10 months ago

TI__Genius 11125 points

Hi Shinichi,

To account for the power loss via the VBUS switch, you need to look at the RDSON spec (section 7.8 of the datasheet). This is specific to each device variant.

P_switch = (I_BUS)^2 * RDSON, where I_BUS is the VBUS current passing through the device.

For example, TPD1S514-1:
RDSON = 39 mOhm (typical)
I_BUS = 1 A

P_switch = 1*1*0.039 = 0.039 W

Regards,
Eric

0 Shinichi Inoue 9 months ago in reply to Eric Hartigan

Guru 21676 points

Hi Eric,

Thank you for your reply.

I'll share your answer with the customer.

When the customer has an additional question, I consult you again.

I appreciate your great help and cooperation.

Best regards,

Shinichi

+1 Eric Hartigan 9 months ago in reply to Shinichi Inoue

TI__Genius 11125 points

Hi Shinichi,

No problem.

Regards,
Eric

0 Shinichi Inoue 9 months ago in reply to Eric Hartigan

Guru 21676 points

Hi Eric,

The customer has no additional question.

Could you please close this thread.

I appreciate your great help and cooperation.

Best regards,

Shinichi

0 Eric Hartigan 9 months ago in reply to Shinichi Inoue

TI__Genius 11125 points

Hi Shinichi. I will close now.

Regards,
Eric

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TPD1S514: How to calculate the total loss inside the device with FET current pass