IR FET's

Bengali · 1st May 2008, 05:53 PM

Hi,

I'm curious as to why it was mentioned not to use IR brand FET's.
Something about higher frequencies?

This is for 9610 only or any other?

Both digikey and mouser carry only the Vishay/IR IRF9610PBF.

If these are too be avoided, what brand and where do you get the fet's?

Are SEC brand any good?

Thank you.

GRollins · 1st May 2008, 06:24 PM

The IRF P-channel parts behave oddly as the frequency increases. This does not apply to the N-ch parts.
Go to the Fairchild site and cross reference the IRF to their part, then go to Mouser, who carries the Fairchild parts at reasonable prices.

Grey

EDIT: Sorry, didn't hit the part about why. The IRF P-channel MOSFETs' gain decreases with increasing frequency. It's not a deal killer, but it can be annoying. If you're using the IRF parts in a circuit with feedback (which includes 99.999% of the circuits out there) you won't have any problems. It's also not a problem if you're using the part as a follower, meaning something like a normal push-pull amplifier output. In an application like that, there's almost no difference at all.
If you're still nervous about it, remember that there are zillions of perfectly happy Aleph owners out there who are listening to IRF parts every day. It's not worth losing sleep over.

Bengali · 1st May 2008, 07:42 PM

very interesting

Thank you for sharing.

1st May 2008, 05:53 PM	#1
Bengali diyAudio Member Join Date: Oct 2006	IR FET's Hi, I'm curious as to why it was mentioned not to use IR brand FET's. Something about higher frequencies? This is for 9610 only or any other? Both digikey and mouser carry only the Vishay/IR IRF9610PBF. If these are too be avoided, what brand and where do you get the fet's? Are SEC brand any good? Thank you.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

1st May 2008, 06:24 PM	#2
GRollins diyAudio Member Join Date: Feb 2001 Location: Columbia, SC	The IRF P-channel parts behave oddly as the frequency increases. This does not apply to the N-ch parts. Go to the Fairchild site and cross reference the IRF to their part, then go to Mouser, who carries the Fairchild parts at reasonable prices. Grey EDIT: Sorry, didn't hit the part about why. The IRF P-channel MOSFETs' gain decreases with increasing frequency. It's not a deal killer, but it can be annoying. If you're using the IRF parts in a circuit with feedback (which includes 99.999% of the circuits out there) you won't have any problems. It's also not a problem if you're using the part as a follower, meaning something like a normal push-pull amplifier output. In an application like that, there's almost no difference at all. If you're still nervous about it, remember that there are zillions of perfectly happy Aleph owners out there who are listening to IRF parts every day. It's not worth losing sleep over.

1st May 2008, 07:42 PM	#3
Bengali diyAudio Member Join Date: Oct 2006	very interesting Thank you for sharing.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)