50W? Really?

[ppTRN]

While looking for a suitable P+N mosfets to use in an H bridge for a 12V 10A brushed motor I came across this alleged beast.
https://www.lcsc.com/products/MOSFETs_381.html
I intend to use two of these in order to complete the H bridge. But I mean... Should I trust this devices specs? 50W of power dissipation limited by the jucntion temperature of 150°C on such a small device!

Do you think that is for real?

[Ian.M]

Your link gives a product category search, not an individual device.

However power MOSFET power ratings are *NEVER* for real, as they are generally specced for the entire underside of the package + the leads to be kept at 25°C, which is generally hard to do due to the high heat flux through a rather small surface area, even with an actively cooled heatsink system.

[Siwastaja]

You can pretty much trust datasheet values but only if you know exactly what they mean. There are many catches for "young players", such as some values that apply in irrelevant conditions - but as long as those conditions are mentioned, it's technically correct information.

For a 12V 10A brushed motor controller, assuming you would be aiming for something sensible like 95 to 99% efficiency, why would 50W power dissipation number matter? You would be dissipating only a few watts. In DC motor controllers nowadays, it's easier to get more silicon and reduce power dissipation, than to design heatsinking.

[PCB.Wiz]

While looking for a suitable P+N mosfets to use in an H bridge for a 12V 10A brushed motor I came across this alleged beast.
https://www.lcsc.com/products/MOSFETs_381.html
I intend to use two of these in order to complete the H bridge. But I mean... Should I trust this devices specs? 50W of power dissipation limited by the jucntion temperature of 150°C on such a small device!

Do you think that is for real?

You are right it is not really 'real', it assumed you can take all the heat away.
On a practical SMD pcb, low single digit watts are practical. The lower, the cooler.

You should forget 'watts' and instead focus on Rds on, and get the lowest loss. 

Sum the P and N fet rds   eg 7+13m Ohm typical  of the G100C04D52 from GOFORD is 700mW in one package and 1300mW in the other.
You could look at a simple top cooling heatsink, on those low profile packages, if you expect to push 10A continual.

 

[bostonman]

If I'm understanding your question correctly, the answer is: you're not looking for wattage in the MOSFET because it's not 10A to ground.

Use the formula I^2(R), and, for a MOSFET, you might find a Rds on of 50m ohms (probably lower - I didn't search).

The wattage from the MOSFET would then be 600mW if your current is 12A (I rounded up a bit from your 10A.