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

Chip Amps Amplifiers based on integrated circuits

terminating unused parts of multichannel opamps
terminating unused parts of multichannel opamps
terminating unused parts of multichannel opamps 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 2nd June 2004, 11:26 PM   #1
matjans is offline matjans  Netherlands
diyAudio Member
 
matjans's Avatar
 
Join Date: Aug 2003
Location: Utrecht, NL
Send a message via MSN to matjans
Default terminating unused parts of multichannel opamps

hey guys,

i'm designing an active filter with a couple of quad opamps of which i only need 3 amps per ic. One of the opamps (per ic) is unused. After reading the 'opamps for everybody' chapter 17 i have a questions.

At the bottom of page 29 there is a paragraph on how to correctly terminate unused parts of opamps. In the drawings they mention 'half supply'. I'm guessing that when using +/0/- rails the half supply == 0 or ground. Am i correct?

Second question; what does 'open' or 'zero' mean in the rightmost picture at the top of page 30?

/matti
  Reply With Quote
Old 2nd June 2004, 11:39 PM   #2
peranders is offline peranders  Sweden
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
terminating unused parts of multichannel opamps
You should always tie unused opamps to something.

Some opamps can be tied to negative supply but check datasheet first, like the LM324 and any rail-to-rail opamp.

If you have a dual supply must connect the opamp as voltage follower (inverting input to output) and the non-inverting input to ground or to some potential within the common mode limits.

Why you should do it? To minimize the influence of the unused opamp to the ones wich are in use.

Zero = connect
Open = do not connect

but seriously I think they ment that ZERO some resistance, like 1 kohms or so.
__________________
/Per-Anders (my first name) or P-A as my friends call me.
  Reply With Quote

Reply


terminating unused parts of multichannel opampsHide 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
FS: M³ and STEPS PCB & a few parts (all unused) iampivot Swap Meet 6 28th March 2008 11:56 AM
Parts FS : Output Devices/Diodes/Regulators/Opamps and Misc. Items dtm1962 Swap Meet 5 8th September 2007 02:25 AM
Terminating Sennheiser HMD 280 Pro kinghong Parts 0 16th February 2007 08:41 PM
OPAMPS and other Parts for Sale or Trade (Looking for up to 10 47uF NX-Hi-Q BlackGate dtm1962 Swap Meet 6 27th August 2006 03:39 AM


New To Site? Need Help?

All times are GMT. The time now is 02:42 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki