Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

MOSFET Questions
MOSFET Questions
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
Thread Tools Search this Thread
Old 13th December 2003, 11:15 PM   #1
Solid Snake is offline Solid Snake  United States
diyAudio Member
Join Date: Feb 2003
Default MOSFET Questions

I have read that MOSFETs will pass current from drain to source in either direction. Is there a voltage drop from D to S? Also is the gate voltage to Drain-to-Source impedance relationship linear or exponential? I see on datasheets gate voltage vs drain to source amps but I need to know exact ohm values for given gate voltages.
  Reply With Quote
Old 14th December 2003, 08:18 AM   #2
azira is offline azira  United States
diyAudio Member
Join Date: Dec 2003
Location: Near Seattle
That's partially true. Technically there is no difference between the Drain and Source of a MOSFET, it's symetrical and can be used either direction (whereas BJTs are not symetrical). But there is also a base "terminal" and if there is a Vbase-source, then the threshold voltage and some other parameters change. For this reason, the base is usually tied to a pin labeled as the source. After that happens, the source terminal is fixed.

As far as resistance, there is an apparent Rds which can be viewed as (Vds / Ids). But the equation for Rds is not a linear property. Since this is tied to the transconductance, you can't figure out Rds of a FET without measuring Gm.
  Reply With Quote


MOSFET QuestionsHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
MOSFET questions Orbus Solid State 15 9th January 2008 02:54 PM
mosfet amp questions ... Ahmad_tbp Solid State 57 1st July 2005 04:01 PM
Mosfet Citation 12 build questions Rjones5296 Pass Labs 2 17th December 2004 04:53 AM
aleph 5 mosfet questions Al Bundy Pass Labs 2 29th November 2003 09:32 AM
Transistor / MOSFET Questions... Solid Snake Solid State 4 27th February 2003 09:05 PM

New To Site? Need Help?

All times are GMT. The time now is 11:45 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio