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MOSFET hfe Beta current gain.

Started by Harry D October 31, 2014
Attached MOSFET device with a nice hfe of 95, who knew?

http://www.genesicsemi.com/images/products_sic/sjt/GA50JT17-247.pdf

Enjoy,  Harry

On Fri, 31 Oct 2014 10:19:20 -0700, "Harry D" <harryd@tdsystems.org>
wrote:

>Attached MOSFET device with a nice hfe of 95, who knew? > >http://www.genesicsemi.com/images/products_sic/sjt/GA50JT17-247.pdf > >Enjoy, Harry
You're letting the symbol confuse you. It's not an IGBT, it's a BJT-current-driven-into-channel MOS device, whatever you might call that ;-) ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
On 31/10/14 18.19, Harry D wrote:
> Attached MOSFET device with a nice hfe of 95, who knew? > > http://www.genesicsemi.com/images/products_sic/sjt/GA50JT17-247.pdf > > Enjoy, Harry >
I vote that it is a some "bastard" J-FET, that have the PN-gate forward biased?: "Gate Oxide Free SiC Switch" "Compatible with Si MOSFET/IGBT Gate Drive ICs" "Gate On Voltage VGSON" 3,5V figure 4 (actually figure 7) Glenn
On Fri, 31 Oct 2014 10:32:19 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

>On Fri, 31 Oct 2014 10:19:20 -0700, "Harry D" <harryd@tdsystems.org> >wrote: > >>Attached MOSFET device with a nice hfe of 95, who knew? >> >>http://www.genesicsemi.com/images/products_sic/sjt/GA50JT17-247.pdf >> >>Enjoy, Harry > >You're letting the symbol confuse you. It's not an IGBT, it's a >BJT-current-driven-into-channel MOS device, whatever you might call >that ;-) > > ...Jim Thompson
After some more pondering I realize it's a giant _lateral_ NPN, which gets the voltage wa-a-a-ay up. (Lateral PNP's on my custom microchips typically have breakdown voltages in excess of 30V, on an otherwise 5V process.) ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
On Fri, 31 Oct 2014 10:19:20 -0700, "Harry D" <harryd@tdsystems.org>
wrote:

>Attached MOSFET device with a nice hfe of 95, who knew? > >http://www.genesicsemi.com/images/products_sic/sjt/GA50JT17-247.pdf > >Enjoy, Harry
Cool, an SiC bipolar transistor. I've seen a strange effect in phemts, both depletion and enhancement mode devices. As you raise the gate voltage, the drain currrent goes way up as the gate begins to draw current, around +0.6 volts or so, almost a bipolar effect on top of the usual jfet-like behavior. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
After all, JFETs are nothing more than UJTs with a very thin active 
channel area (so the gate causes cutoff) and a short channel length (so 
the conductivity modulation is generally small).

I haven't been able to observe much if any effect with generic silicon 
JFETs, but perhaps the structure of PHEMTs does something.  The channel is 
a thin 2DEG, it might be the conductivity modulation affects the entire 
bulk and massively increases conductivity.

Tim

-- 
Seven Transistor Labs
Electrical Engineering Consultation
Website: http://seventransistorlabs.com

"John Larkin" <jlarkin@highlandtechnology.com> wrote in message 
news:jrq75atog5j9dqv93jsmt6m5uqnl0dg08h@4ax.com...
> On Fri, 31 Oct 2014 10:19:20 -0700, "Harry D" <harryd@tdsystems.org> > wrote: > >>Attached MOSFET device with a nice hfe of 95, who knew? >> >>http://www.genesicsemi.com/images/products_sic/sjt/GA50JT17-247.pdf >> >>Enjoy, Harry > > Cool, an SiC bipolar transistor. > > I've seen a strange effect in phemts, both depletion and enhancement > mode devices. As you raise the gate voltage, the drain currrent goes > way up as the gate begins to draw current, around +0.6 volts or so, > almost a bipolar effect on top of the usual jfet-like behavior. > > > -- > > John Larkin Highland Technology, Inc > picosecond timing precision measurement > > jlarkin att highlandtechnology dott com > http://www.highlandtechnology.com >