Difference between IRFP240 & IRFP244

[Apogee]

I'm looking at ordering fets and would like to know which I should order.

Price is about the same so that isn't an issue.

The main issue for me is which sounds better???????

The 240 appears to be a higher current device so I'm thinking that is the best choice unless I'm convinced otherwise.

I will make sure they are all from the same lot.

Also, I no longer see the "N" versions listed on Newark's site. What's up with that? Are the N's the only versions now available or has IR dumped them?

On a side note, does anyone know a reasonably priced source for IRF240's? $11.00 each from Newark seems a bit steep....

Thanks for the help!!!!

[Zen Mod]

Originally posted by Apogee

I'm looking at ordering fets and would like to know what which I should order.

Price is about the same so that isn't an issue.

The main issue for me is which sounds better???????

The 240 appears to be a higher current device so I'm thinking that is the best choice unless I'm convinced otherwise.

Also, on a side note, does anyone know a reasonably priced source for IRF240's? $11.00 each from Newark seems a bit steep....

I will make sure they are all from the same lot.

Also, I no longer see the "N" versions listed on Newark's site. What's up with that? Are the N's the only versions now available?

Thanks for the help!!!!

fets for what?

[Apogee]

Alephs, Zens and whatever else...

I will be ordering IRFP044's for Aleph-X's...

[Zen Mod]

Originally posted by Apogee
Alephs, Zens and whatever else...

I will be ordering IRFP044's for Aleph-X's...

what's with IRFP150N?

[gl]

Steve,

Most people use the 240 instead of the 244. I buy mine at Digikey. The only parts available now are the lead free ones and someone along the supply chain has taken the opportunity to almost double the price to about $4.50 (for 1). A bit of rip really.

Fairchild no longer lists the IRFP240 but shows the FQA19N20C as a sub. It looks like a nice part. Mouser charges $1.92 for 1.

Cheers,
Graeme

[Babowana]

Originally posted by Apogee


The main issue for me is which sounds better???????

I'm also very intersted in that which sounds better and who could
answer the question. By the way, Papa still uses 240. But, when
he starts using 244, it might be hmm... sold out tomorrow.
I might have to buy 100 pcs and keep them in the draw.
In case . . ., who knows . . . ^^.

[MEGA-amp]

You can always order direct from International Rectifier, thats the easiest, buy a tube of 25 and chances are they'll be from the same batch, which usually yields better matches.

-john

International Rectifier


edit: No stock of Irfp240 at IR, but plenty of the lead free pkg

[jupiterjune]

Mega Amp John-

Nice tip about IRF--I wish I had known about that last week.....



I think one of the most important criteria listed for selecting mosfets is the input capacitance. IRFP 240's are in the 1200pf range, IRFP 244's, (and 250's) are in the 2400pf range (if I recall the numbers correctly from the datasheets). You get more more high frequency distortion with higher input cap.

TO220 devices, such as the IRFP 634's and 9630's are in the 600pf input capacitance range, but offer about half the power handling. I used the 634's in an A-75 and also in an aleph mini, and they sounded just fine. (bias current in the mini .66 amps for each device).

The TO220's require a number 4 mounting screw if they are to be isolated from the heatsink -- not so easy to tap, so if you are using a lot of output devices, go with the TO247's.

JJ

[Apogee]

Thanks everyone!!!

240's it is...

PS - I'm still looking for a lower cost source for IRF240's if anyone knows of one...

[Malotron]

http://www.tech-diy.com/hexfets.htm
As they are already matched sets you save by only buying what your project requires.

Fairchild no longer lists the IRFP240 but shows the FQA19N20C as a sub. It looks like a nice part.

Looks swell on paper...anyone daring to a non IR fet?
-------------------------------------------FQA19N20C IRFP240
gFS Forward Transconductance--------- 10.8 ------------ 6.9
Ciss Input Capacitance------------------- 1080 pF ------ 1300 pF
PD Power Dissipation---------------------- 180 W -------- 150 W
RθJC Thermal Resistance------------------ 0.69 °C/W -- 0.83 °C/W

-Mal