On Mouser, the first result for "IRFP450" costs almost $10/ea: http://www.mouser.com/ProductDetail/Vishay-Siliconix/IRFP450/?qs=sGAEpiMZZMshyDBzk1%2fWizSW%252bwlCH%2fhMNDz4UodUBMI%3d

However, they also sell a lead-free version which costs $3/ea: http://www.mouser.com/ProductDetail...=sGAEpiMZZMshyDBzk1/Wi1F3z9PgzPBnCSufrOup6kg=

Why is latter so much cheaper? Is there a quality difference? All the specs look the same--in fact it even looks like the response time is faster on the $3 version.

Also, would I be correct in assuming I could solder with PbSn on the lead-free MOSFET?

 

the price depends on the number sold, the lead free sells better now, so has a better price. yes you can use lead type solder to solder to lead free parts.

 

Note the difference between IRFP450 and IRFP450A. The A version has some better parameters, which hints that is being made using some newer process / technolgoy. This basically means that the non-A versions are old, possibly no longer manufactured, and thus their price is higher.
PBF meand Pb free, but the A before it is the important part.

 

Note the difference between IRFP450 and IRFP450A. The A version has some better parameters, which hints that is being made using some newer process / technolgoy. This basically means that the non-A versions are old, possibly no longer manufactured, and thus their price is higher.
PBF meand Pb free, but the A before it is the important part.

... but the A version is the cheaper one...?

 

The key is that the new A versions are what is currently produced and likely are produced in high volume.
On the other hand the non-A are old and fewer are made, if any at all, which makes their price go up.

Another factor could be that the new process used to make the A versions is somehow faster or cheaper to do than the process used to make the old ones.

 

... but the A version is the cheaper one...?

Marketing sets the pricing, not engineering. Any more questions about pricing not making sense?

 

OK thanks... I just wanted to make sure I wasn't missing anything on the technical side.