Power dissipation

[Archit]

Hello people!
If losses in my MOSFET is areound 30W and in datasheet it says that it can disspate 1.67KW( ofcourse at Tj=25 C, but assuming my Tj=25 C). So do I need a Heat Sink...
Thanks in advance

 

[rjenkinsgb]

Yes, definitely, otherwise it will heat up at a similar speed to a 30W soldering iron, or even faster..

You need quite a big heatsink as well, eg. a 4 degrees C per watt type would heat by 120'C above ambient when dissipating 30W.

 

[dknguyen]

Hello people!
If losses in my MOSFET is areound 30W and in datasheet it says that it can disspate 1.67KW( ofcourse at Tj=25 C, but assuming my Tj=25 C). So do I need a Heat Sink...
Thanks in advance

What's the MOSFET datasheet? 30W sounds too high for most single package MOSFETs, regardless of heatsink size since there are diminishing returns as heatisnks get bigger.

 

[Nigel Goodwin]

What's the MOSFET datasheet? 30W sounds too high for most single package MOSFETs.

His claimed 1.67KW sounds even worse - assuming that's correct?, then it's a seriously large device, and 'might' be able to dissipate 30W with no extra heatsink.

 

[rjenkinsgb]

With a 1600W rating, it's presumably a "module" style for bolting to a heatsink.

On their own they have pretty bad thermal resistance to air as most of the body is plastic, plus just one polished metal surface.
eg.
**broken link removed**

Edit - just noticed the "back order" delay on those - 2020!

 

[ronsimpson]

So do I need a Heat Sink...

What part? Part number? Data sheet? more information please.

 

[Archit]

What part? Part number? Data sheet? more information please.

Please find the datasheet attached.

 

[Archit]

What's the MOSFET datasheet? 30W sounds too high for most single package MOSFETs, regardless of heatsink size since there are diminishing returns as heatisnks get bigger.

Please find the datasheet attached above

 

[Archit]

With a 1600W rating, it's presumably a "module" style for bolting to a heatsink.

On their own they have pretty bad thermal resistance to air as most of the body is plastic, plus just one polished metal surface.
eg.
**broken link removed**

Edit - just noticed the "back order" delay on those - 2020!

It is written the product will be dispatched on 24/07

 

[Archit]

ith a 1600W rating, it's presumably a "module" style for bolting to a heatsink.

On their own they have pretty bad thermal resistance to air as most of the body is plastic, plus just one polished metal surface.
eg.

Can you ellaborate plese?

 

[Nigel Goodwin]

Can you ellaborate plese?

He was presuming a large module, rather than a single device - as already mentioned dissipating 30W is like a soldering iron (and will get that hot) - so you're likely to need a decent heat sink.

What are you actually trying to do with such a serious device?.

 

[Archit]

What are you actually trying to do with such a serious device?.

It is my master's project. power supply for ion thrusters

 

[Nigel Goodwin]

Big heatsink then - and see how hot it gets.

 

[rjenkinsgb]

VERY big!

If it's a design that is suppose to work on space, all heatsink dissipation must be by pure IR radiation - no conduction.
That means a large flat plate (or use the walls of a metal enclosure) rather than finned heatsink for air-conduction cooling.

The design has to allow for such aspects.