opamp buffers power output q - 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 7th October 2004, 07:16 PM   #1
diyAudio Member
 
Join Date: Mar 2004
Location: Borås Sweden
Send a message via ICQ to PederBass
Default opamp buffers power output q

Hi!
Just want to get some input in a question I been thinking about...

What is the relationship between a opamp-buffer's output current vs supply current when looking at it's power dissipation?

Tryin to make my q clearer...If a buffer's data say's :
output current 100 mA
supply current 10 mA
And...PD 1W

Does this means that, with 30v ps, u can take out:

(1W/30v = 33.3 mA
and supply current 10 mA = 33.3 - 10 )= 23.3 mA?
That is u cant take out MORE than 23.3 mA?

Or is there another relationship since one data is DC mA and the other AC mA?

Greatly appreciate any answer...

Thanks

/Peder
  Reply With Quote
Old 7th October 2004, 07:28 PM   #2
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Supply current of 10 mA is with no load.
Output current (up to 100mA) is added to supply current in appropriate supply lead (+V or -V).
Pd will depend not only on load current, but supply voltage and output voltage as well. Power dissipation also depends on output stage class of operation, we can assume class B/AB.
  Reply With Quote
Old 7th October 2004, 08:00 PM   #3
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Please also have a look at maximum power dissipation vs. temperature and package type.

For BUF634 in TO-220, max. allowed power dissipation is 2W without heatsink (free air). With infinite heatsink, maximum allowed power dissipation increases to 9W ! This says that reasonable heatsink may increase Pd considerably.
  Reply With Quote
Old 8th October 2004, 09:32 PM   #4
diyAudio Member
 
Join Date: Mar 2004
Location: Borås Sweden
Send a message via ICQ to PederBass
Thanx PMA!
Guess that confirmed what I was into..I think..

anyway thnx..

/Peder
  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
Opamp output resistor.. jethdub Chip Amps 3 21st January 2008 03:46 PM
Regulate the psu of a power opamp with a similar power opamp? Franz G Chip Amps 34 19th October 2004 10:49 AM
Delayed power up when using buffers Nuuk Chip Amps 17 14th September 2004 06:06 AM
power output calculations, rated power and required power output metebalci Tubes / Valves 7 22nd February 2004 05:49 PM
Over-current protection in Audio IC Output Buffers ppl Solid State 1 21st October 2003 06:35 AM


New To Site? Need Help?

All times are GMT. The time now is 12:59 AM.


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