Newer Power FETs

where to get parts for building your own transmitter.

Newer Power FETs

Postby Tom WA3KLR » Sat Apr 09, 2011 3:59 pm

Steve WA1QIX mentioned a new FET on the AM Forum board recently – the CMF20120D silicon-carbide 1200 Volt MOSFET:

http://amfone.net/Amforum/index.php?topic=27328.0

I have been inactive on this board for several years, but I try to keep an eye on new FETS. Here are some other newer FETs of the last 2 1/2 years or so that may be appealing also. They are normal price range and all three of these are 600 Volt
N-channel power FETs, TO-247 style of package, and have “good drive efficiency”/low gate charge for their size:

ST STY60NM60 RDSon 0.065 Ohm, Id 60 Amps, Qg = 178 nC.

Fairchild FCH35N60 RDSon 0.079 Ohm, Id 35 Amps, Qg = 139 nC.

ST STW20NM60FD RDSon 0.26 Ohm, Id 20 Amps, Qg = 37 nC.
Tom WA3KLR AMI #77
Tom WA3KLR
Member
 
Posts: 47
Joined: Sun Mar 21, 2004 12:30 pm
Location: Quakertown, Pennsylvania

Re: Newer Power FETs

Postby Tom WA3KLR » Thu Apr 21, 2011 4:44 pm

I have updated a list of FETs I tested 4 years ago with the 3 newer ones above. The list ranked the power FETs according to ease-of-drive; the higher the Rule of Thumb number the easier the FET is to drive.

Go to this AM Forum topic to see the updated list :
http://amfone.net/Amforum/index.php?top ... #msg209862
Tom WA3KLR AMI #77
Tom WA3KLR
Member
 
Posts: 47
Joined: Sun Mar 21, 2004 12:30 pm
Location: Quakertown, Pennsylvania

Re: Newer Power FETs

Postby Tom WA3KLR » Fri Nov 18, 2011 11:23 am

Friday, November 18, 2011 Update

The latest interesting FET I spotted in September, appears to be faster switching than previous FETs. So this could be a real good choice for 40 meters. It is made by IXYS and the data sheet I have (March 2011) is labeled “Advance Technical Information”. It is available from both Digikey and Mouser for $11 each. I have not ordered any.

But the part is:

Polar3 HiPerFET 600V, 64 Amps, Rds(on) = 95 milliOhms, Qg(on) = 145 nC.

IXYS IXFK64N60P3 TO-264 package
and IXFX64N60P3 PLUS247 package.

My “Rule-of-thumb ease of drive number” based on this part's data sheet calculates to 58, which means it is relatively easy to drive for it’s size compared to most other power FETs.

* 11/19 - Here is the link to the IXYS overview sheet on the design of their new PolarP3 FET family:

http://www.ixyspower.com/ProductRelease ... _final.pdf
Last edited by Tom WA3KLR on Sat Nov 19, 2011 6:03 pm, edited 3 times in total.
Tom WA3KLR AMI #77
Tom WA3KLR
Member
 
Posts: 47
Joined: Sun Mar 21, 2004 12:30 pm
Location: Quakertown, Pennsylvania

Re: Newer Power FETs

Postby Gilly » Fri Nov 18, 2011 11:01 pm

Hi Tom

You certainly have done quite a bit of testing to come up with all this information .... very handy to know as 40M is more difficult than 160/80M...to get things going with high efficiency.....
This is by my experience anyway ... my output balun / transformer does get warm to hot depending how much power I push it to....

In Australia our power levels are quite low compared to yours ..... 120Watts Carrier modulated to appox 100% :mrgreen:
So efficiency is not all that of an issue...only personnal satisfaction.....

The FETs I use now are the 11N90 / C's and IRF840s .........

Those you mentioned have not come across and would probably need to be imported etc:


Wayne
Gilly
Class E Enthusiast
 
Posts: 167
Joined: Tue May 15, 2007 6:59 pm
Location: Mt.Eliza Victoria Australia

Re: Newer Power FETs

Postby Diego-CX4DI » Mon Nov 28, 2011 7:45 am

I got exelent perfomance in 40M using the APT's : APT5024BLLG.

some test at QRZ.com/cx4di

73's
Diego
CX4DI
Class E with PWM modulation
Diego-CX4DI
Member
 
Posts: 43
Joined: Fri Sep 30, 2005 10:22 am
Location: Montevideo-Uruguay

Re: Newer Power FETs

Postby steve_qix » Fri Dec 23, 2011 4:53 pm

The lower voltage FETs are *ALWAYS* easier to drive, and may even be faster.

However, the distinct and ever-present disadvantage is that you must reduce the high voltage supply significantly to keep a reasonable safety factor. For instance, if using a 600V MOSFET, the high voltage power supply must be reduced from 130V to 85V to maintain the same safety factor as is afforded by an FQA11N90 and a 130V (45 volts at carrier) supply.

With a 600V MOSFET, you could expect to be able to run about 30 volts at carrier, with an 87V total supply voltage and NO MORE than that.
Visit the class E web site at:

http://www.classeradio.com
User avatar
steve_qix
Class E Guru
 
Posts: 434
Joined: Fri Jan 31, 2003 11:03 am
Location: Townsend MA


Return to Parts and Sources

Who is online

Users browsing this forum: No registered users and 1 guest

cron