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Old 19th March 2013, 08:24 PM   #271
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Got decent Yfs. Power rated to 200w, like IRF150. These babies should burrn nice.
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Old 19th March 2013, 09:30 PM   #272
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I would bet you could get away with 25V and 1.5A for an operating point without worry
So, how can you calculate an approximate Drain/Output impeadance from the data sheet?
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Old 19th March 2013, 09:40 PM   #273
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I ordered 8. 4 will stay with me and 4 will journey to PLDF. They will not be in until 5/17.
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Old 19th March 2013, 11:32 PM   #274
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They should be run on a curve tracer to see what they will do in "normal" operation, imo... they're sort of like the "sweep tubes" of solid state, in that they seem to be able to handle insane amounts of peak power...

I looked briefly at the three devices they sell, and one of the earlier ones sort of seemed maybe to be a better audio choice based on the curves in the pdfs, but quite frankly I am unsure totally.

I mean what do you expect from a stuffed bear? Everything *is* fuzzy.

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Old 20th March 2013, 01:34 AM   #275
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The others look pretty good too. The "New ZFET" device has the wonky Capacitance begining down below around 15Vds where the others it is below about 25Vds. The capacitance for the 10120 device is otherwise about the same but the 20120 is subtantially more. The gain of the 10120 is lower but the gain of the 20120 is about the same. Thermal resistance is good and about equal to the 10120 device but the 20120 device seems to have substantially less and an apparent larger die size from all these factors.
Seems like the new ZFET has the benifets of both of the earlier devices in 1 smaller die?
The Transfer Curves showing more "ohmic region" with Vds is an indication of lower drain impeadance but, I couldn't explain why. I beleive we do want to see that though???
I like it!
I guess as Papa said, there will be some new offerings...
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Old 20th March 2013, 01:40 AM   #276
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Speaking of new offerings, This week in San Diego, is the APEC. The confrence for power coversion industry products etc. where most of these SiC and GaN devices are used. It is likely new things will be anounced and discussed there. We will see.
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Old 20th March 2013, 02:10 AM   #277
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Quote:
Originally Posted by flg View Post
Speaking of new offerings, This week in San Diego, is the APEC. The confrence for power coversion industry products etc. where most of these SiC and GaN devices are used. It is likely new things will be anounced and discussed there. We will see.
flg is right, this is "big week" for wide bangap semiconductor vendors. I'm currently at about 35,000 feet heading for Los Angeles, California. I'm two days late due to unavoidable meetings with the head shed and a canceled flight this morning. The meeting is actually in Long Beach, but hey, Long Beach and San Diego are both in Southern California, so close enough.

My "boys" are already at the meeting. My impression from their comments is that, as expected, the SiC MOSFET is rather old news (although with SemiSouth out of the picture, they are making progress). Also as expected, the GaN folks are trying to make the biggest claims, with Transphorm catching my guy's attention the most. But when you are actually selling, like the Cree MOSFET probably is, the louder you yell does not mean the bigger your sales. Big accounts are sold direct. But who knows? That's why you play the game, to see who wins!

I'll post my impressions once I've had a look tomorrow.
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Old 20th March 2013, 04:01 AM   #278
qusp is offline qusp  Australia
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what do you think of the EPC GaN SMD fets (EPC2007 for example) for linear duties as line level power follower/headphone amp? nice looking curves, very low charge and very low cap, pita tiny BGA type package, but that I can work around if its worthwhile. they are designed for power switching and Class D and low duty cycle, but opc put me onto them when I was asking about the directFET from IRF for linear wrt dissipation and i'm toying with a few ideas for PCBs. matching will be an issue and load-line will need to be well sorted to avoid exceeding max VGS. Matching at least is offset to some degree by their very low change vs voltage/heat and virtually no parasitic diode effect. pretty linear curves in preferred operating conditions though.

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Old 21st March 2013, 12:29 AM   #279
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Default APEC Impressions

APEC, by the way, stands for "Applied Power Electronics Conference" which is the major North American power electronics trade show and technical conference sponsored by the IEEE.

The growth over the last few years in wide bandgap power semiconductor presence at APEC continued this year, with especially aggressive marketing by GaN start ups. SiC is quieter, but that is because it is more established. Cree was the top dog by far, with Rohm right behind, and Fairchild (SiC BJT) trying to keep up. The "show" (as the exhibition is called by the booth dwellers) ended at 2 pm Pacific time today and I watched John Palmour, one of the founders of Cree, take a bow in front with some of his sales people. I may bump into him tonight at the social event. I'll make him buy me a beer if he starts gloating about SemiSouth.

While Transphorm and EPC, backed and under pressure by venture capital investors, are making the usual save the world presentations, apparently everyone is settling into the reality of having to deliver on promises, more extravagantly made by GaN than anyone else, judging from what I heard happened last night at the usual "Are wide bandgap power semis real?" Rap session. In years gone by this is where the GaN vs. SiC boxing match is aired out the most, but an audience member got up last night and asked why the panel of mixed SiC and GaN folks was being so agreeable. The audience came for a fight but they were getting a church sermon instead. Ha! Not when I served on such panels!

SiC parts relevant to building amplifiers are more available than GaN parts for sure based on our surveys of the booth dwellers. I'll have some more to report about new devices when I get a few back to the Bat Cave in Starkville.

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Old 21st March 2013, 01:45 AM   #280
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