Source to ground?
-- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
Sorry, I mistyped. Yes, Source to gate. Or ground in your case.
-- Regards, Joerg http://www.analogconsultants.com/
Maybe a 12V zener source to gate?
It will be completely pinched off at -8V or so, so the channel leakage current of 100nA or whatever will flow through the zener to ground/gate.
End result is that more voltage appears across the switch than the transistor.
Best regards, Spehro Pefhany
-- "it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
I already looked at the datasheet.
I still can't see what the circuit is supposed to do, and the description of what the board is supposed to do is pretty vague to start with, which doesn't help.
So back to Q2, there's a switching device in series with a pushbuton switch, with the gate wired to ground.
Why?
Vague ?>:-}
Depletion mode FET, so, when pushbutton is activated, it's a current-limited source rather than just a switch? ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: Contacts Only | |
| 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.
Ah- that works for me.
But the off gate-to-source voltage was not limited. I think that's what the "dumb" was all about... not real clear. ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: Contacts Only | |
| 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.
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.