CSD19535KTT: Checking the MOSFET SAFE operating area for Motor Control Application

Chaitanya,

Thank you for your interest in our MOSFETs.

On ti.com we have collated our technical information regarding MOSFETs here: https://www.ti.com/power-management/mosfets/support-training.html

Concerning your SOA question

On this page is an article explaining how to use/interpret SOA, it is here: https://e2e.ti.com/blogs_/b/powerhouse/posts/understanding-mosfet-data-sheets-part-2-safe-operating-area-soa-graph

Also an article on pulsed current ratings and how they relate to the SOA here: https://e2e.ti.com/blogs_/b/powerhouse/posts/understanding-mosfet-data-sheets-part-4-mosfet-switching-times

Essentially you are interpreting the SOA correctly but more details on this are in the articles above.

Concerning your question about current

For a current of 42 Amps and a resistance of 3.2mOhm you will get the drop of 0.1344V, I am not sure where you get 24A drain current from.

When using resistance you will need to also take into account the resistance increase due to temperature, Fig8 in the datasheet, which impacts power loss and current . Also when you calculate the power loss expected in your device we wrote an article to try to guide our customers on typically what each package can dissipate in a typical system, this article is here:  https://e2e.ti.com/blogs_/b/powerhouse/posts/selecting-the-right-power-mosfet-power-block-package-for-your-application

I assume you are trying to calculate losses in a motor, there are more losses than simply resistance to consider.

In the MOSFET technical information link above is a tools section, this tools section has a free, downloadable excel based calculator specifically for BLDC motors, it is located here: https://www.ti.com/tool/MOTOR-DRIVE-FET-LOSS-CALC

You can use this tool to calculate losses and select and compare various MOSFET choices based on you motor application conditions..

Thanks

Chris