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

LM3886 Mute
LM3886 Mute
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 17th August 2004, 04:32 PM   #1
richie00boy is offline richie00boy  United Kingdom
Did it Himself
diyAudio Member
 
richie00boy's Avatar
 
Join Date: Nov 2003
Location: Gloucestershire, England, UK
LM3886 Mute
Default LM3886 Mute

I have been searching the forum on this subject and I have not found the answer. Why can I not just tie the mute pin directly to the -ve rail? If you just need to pass a minimum of 0.5mA why bother with the resistor?
  Reply With Quote
Old 17th August 2004, 04:37 PM   #2
cm961 is offline cm961  Canada
diyAudio Member
 
cm961's Avatar
 
Join Date: Jun 2001
Location: Peterborough, Ontario
If the pin isn't current limited it could draw a lot of current from -ve and blow up the chip would be my guess. Or it could unevenly load the power supply so that your + and - voltages weren't the same.

Pete
  Reply With Quote
Old 17th August 2004, 06:05 PM   #3
richie00boy is offline richie00boy  United Kingdom
Did it Himself
diyAudio Member
 
richie00boy's Avatar
 
Join Date: Nov 2003
Location: Gloucestershire, England, UK
LM3886 Mute
Yes. I should have woken up when I looked at the equivalent circuit on the datasheet. With a direct connection there will only be an internal 1k resistor limiting the current, probably resulting in a hot chip if not failure.
  Reply With Quote
Old 17th August 2004, 08:15 PM   #4
peranders is offline peranders  Sweden
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
LM3886 Mute
As I always nag about: Read the datasheet even though if you don't understand most of it. National's datasheets happen to be very good and this particular issue is clearly written about.

Notice also how this resistor have influence of the gain.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Group buy: DCT03 DC trap for big toroidal transformers. Sign up for interest HERE. 65 pcb's in order. 59 paid.
  Reply With Quote
Old 18th August 2004, 09:36 AM   #5
richie00boy is offline richie00boy  United Kingdom
Did it Himself
diyAudio Member
 
richie00boy's Avatar
 
Join Date: Nov 2003
Location: Gloucestershire, England, UK
LM3886 Mute
I too believe in reading the datasheets

The influence of the resistor on the gain was what prompted me to ask the question as I realised that to ensure no attenuation, enough current must flow out the pin. I saw the best way to achieve the absolute least possible attenuation was to just omit the resistor and tie directly to -ve.
  Reply With Quote
Old 18th August 2004, 11:00 AM   #6
jan.didden is offline jan.didden  Europe
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: The great city of Turnhout, BE
There is also a graph in the DS for att versus mute current. It is clear that for currents higher than the indicated one, there is no furter change in gain.

jan Didden
__________________
Cable: a potential source of trouble interconnecting two other potential sources of trouble - Erik Margan
Linear Audio pubs and articles . The SilentSwitcher now at diyaudio store SilentSwitcher. Keeping in touch with SY.
  Reply With Quote
Old 18th August 2004, 11:26 AM   #7
richie00boy is offline richie00boy  United Kingdom
Did it Himself
diyAudio Member
 
richie00boy's Avatar
 
Join Date: Nov 2003
Location: Gloucestershire, England, UK
LM3886 Mute
Indeed. I was just on an elimination of parts mission.
  Reply With Quote

Reply


LM3886 MuteHide 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
LM3886, mute question... CJ900RR Chip Amps 6 6th June 2013 06:07 AM
LM3886 Mute Disable mothman Chip Amps 15 28th January 2013 05:05 AM
lm3886 no mute rtill Chip Amps 21 29th August 2009 05:43 AM
LM3886 - regulator on the mute pin ? ash_dac Chip Amps 8 2nd September 2006 12:28 PM
lm3886 mute LED blabley Solid State 1 30th May 2002 05:51 AM


New To Site? Need Help?

All times are GMT. The time now is 06:12 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
Wiki