CSD19502Q5B: MOSFET power dissipation

Stas Shamanin

Part Number: CSD19502Q5B

Hi!

I wonder how can I calculate maximum power throw MOSFET and if needed the case junction, where to apply and how to calculate it.

Let's take CSD19502Q5B

It is written 3.4 mOhm and maximum continous current 100A (package limited)

Okay, I want to use 100A max, that means P=I*U=I^2*R= 34W

I see RthetaJC 0.8, I should place it 1inch^2 2oz PCB.

I beleive this area is connected to drain, because it is the biggest pad

But I am sure, that is not enough.

I need also connect some case. Should I connect this

On top of IC? Or to this copper area on PCB? Which connection RthetaJC is 0.8?

I would like to find some tutorial or calculators for this, if possible.

Thanks.

over 1 year ago

0 Chris Bull over 1 year ago

TI__Expert 7905 points

Stas,

Thanks for considering our MOSFETs.

We have a document here https://www.ti.com/lit/an/slvafg3d/slvafg3d.pdf

This lists all the MOSFET technical information on the TI website in one easy place.

It has articles that cover your interest area, I would recommend reading the following:

Section 1. Continuous Current ratings
Section 4 : Selecting the right power MOSFET/power block package for your application

In section 5, there are a host of application specific power loss calculators where you can input your application conditions and it will calculate the power loss and you can choose devices easily based on size/cost/performance.

Many thanks

Chris

0 Stas Shamanin over 1 year ago in reply to Chris Bull

Intellectual 450 points

Hi!

Thanks!

But when I click on "Continuous curent rating" I get into "Pulsed curent ratings" datasheet (ssztcj6).

But I got Your point, try to get more understanding, in this project I need to be weight oriented and give straight numbers.

Really nice tool.

0 Chris Bull over 1 year ago in reply to Stas Shamanin

TI__Expert 7905 points

Stas,

I apologize, we will get this link fixed ASAP, the continuous current rating note is here: https://www.ti.com/lit/ta/ssztcp0/ssztcp0.pdf

Thanks

Chris.....

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CSD19502Q5B: MOSFET power dissipation