Germanium transisors and gm - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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
Reply
 
Thread Tools Search this Thread
Old 13th January 2007, 02:38 AM   #1
diyAudio Member
 
Steve Eddy's Avatar
 
Join Date: Sep 2002
Location: Sacramento, CA
Default Germanium transisors and gm

For silicon transistors, gm is approximately 25/Ic. How does one go about calculating gm for a germanium device?

se
  Reply With Quote
Old 13th January 2007, 04:51 AM   #2
diyAudio Member
 
Join Date: Apr 2006
Location: Minnesota
Transconductance is given by

gm=q*Ic/K*T

where q=1.602e-19 (electron charge)
K=1.380e-23 (Boltzmann's constant)
T=Kelvin temperature (degrees Kelvin = degrees Cent + 273=300@ 23 degrees C)

This works out to about 38.5*Ic at 300 degrees Kelvin and is the same for both Ge and Si.
  Reply With Quote
Old 13th January 2007, 08:29 AM   #3
diyAudio Member
 
Piercarlo's Avatar
 
Join Date: Nov 2006
Quote:
Originally posted by sawreyrw
Transconductance is given by

gm=q*Ic/K*T

This works out to about 38.5*Ic at 300 degrees Kelvin and is the same for both Ge and Si.
'Electron voltage" (or speed) is just 25,8 mV at 300 K (usually rounded up to 26 mV). However, for pratical purposes, is convenient use 30 mV in order to take in account the effective working junction temperature (75-80 C for non-stressing working condition of bipolar devices).

Hi
Piercarlo
  Reply With Quote
Old 13th January 2007, 03:38 PM   #4
diyAudio Member
 
Steve Eddy's Avatar
 
Join Date: Sep 2002
Location: Sacramento, CA
Thanks guys!

se
  Reply With Quote

Reply


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Germanium output stage NIC1138 Solid State 28 25th July 2013 06:09 PM
germanium Preamp? prorms Solid State 116 22nd December 2009 04:33 PM
Need Old Germanium transistor datasheets Bakmeel Parts 9 3rd June 2009 07:43 PM
what are the best germanium transistor npn and pnp ?? prorms Instruments and Amps 9 24th August 2008 12:42 AM
What to do with my germanium transistors keantoken Parts 7 6th April 2008 05:05 AM


New To Site? Need Help?

All times are GMT. The time now is 02:24 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2