Lm3886 Pcb - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 20th January 2004, 01:08 AM   #11
diyAudio Member
 
Join Date: Sep 2003
Location: Illinois
OK, I revised the PCB. Heres what I got.

There is a jumper from the gnd to pin 7 and from pin 7 to the resistor to its right.

Will this work fine?

Also, should i connect pins 2, 6 and 11 to gnd also? they don't connect to anything?

Thanks, Mike
Attached Images
File Type: gif bottom_revised2.gif (2.3 KB, 4161 views)
  Reply With Quote
Old 21st January 2004, 01:39 AM   #12
diyAudio Member
 
Join Date: Sep 2003
Location: Illinois
anybody?

I know i havent added the decoupling caps, but i am going 2
  Reply With Quote
Old 21st January 2004, 11:51 AM   #13
diyAudio Member
 
Join Date: Sep 2003
Location: Illinois
Can somebody just tell me if the NC pins should be connected to GND or not?
  Reply With Quote
Old 21st January 2004, 12:23 PM   #14
diyAudio Member
 
bigparsnip's Avatar
 
Join Date: Apr 2003
Location: Cambridge
the nc pins shouldn't be conected to ground or anything else if you can avoid it (just to be on the safe side), however, if you want to fix the chip onto the PCB more solidly, you can just have unconected pads for each of these pins, and solder the legs as normal (as they still won't be conected to anything, kind of like it looks like you have done.

Also, where will you be running the wire from the gnd to the resitor through? will it still be going between the chips legs, as if it is a bare wire it may touch one of them and cause a short or someting.

edit:

Just a thought, what design software are you using?

Also, could you possibly post a scheematic, if you have it, so that it is a bit easier for us to see where things should be going in your design.
  Reply With Quote
Old 21st January 2004, 12:39 PM   #15
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
You should always read datasheet if you have "NC" pins. Sometimes you can use them as guard (some opamps), sometimes the are not used normally but it can also mean "do not connect" meaning DO NOT connect. They can be connected to something internally for production test maybe.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Super Regulator SSR03 Group buy
  Reply With Quote
Old 21st January 2004, 08:42 PM   #16
diyAudio Member
 
Join Date: Sep 2003
Location: Illinois
The schematic i used is from the first page of the datasheet. I am at a library computer now, so I don't have it.

I use the software called PCB Editor.

I will use insulated wires for jumpers.

I didn't think the NC pins had to be connected, but just wanted to make sure.
  Reply With Quote
Old 21st January 2004, 09:09 PM   #17
diyAudio Member
 
bigparsnip's Avatar
 
Join Date: Apr 2003
Location: Cambridge
Hi, I've just tried to have a real look at this and see where the components go and where the external connectors are, and I have realy confused my self, do you have a component overlay to go with this as (assuming it uses all of the smae components as on the national data sheet) it would prove very useful here I think.
  Reply With Quote
Old 21st January 2004, 10:29 PM   #18
diyAudio Member
 
bigparsnip's Avatar
 
Join Date: Apr 2003
Location: Cambridge
Right, I have had a quick bash from scratch using the national reference design from the scheematic, and come up with the board below, which should also allow for reasonalbe sized local power supply decoupling caps to be fitted, as well as having mute circuitry (simply wire in the switch between pads 3 and 4) input conector (signal and ground, on pads 1 and 2) output pads (signal and ground, pads 5 and 6) and the power supply conectors (pads, 7 8 and 9).

If you want a copy of the eagle board files, or the schematic just let me now and I can post them up here for you.

Andrew.
Attached Images
File Type: gif soundnerd3886-1.gif (14.0 KB, 3308 views)
  Reply With Quote
Old 21st January 2004, 10:32 PM   #19
diyAudio Member
 
bigparsnip's Avatar
 
Join Date: Apr 2003
Location: Cambridge
Here is the board without the component overlay, to give you a clearer look at what is going on below.

edit: the red wire is a jumper link to simplfy the board layout a bit, but you could get away with un-insulated wire, as it will be no where near coming into contact with any other bare metal.
Attached Images
File Type: gif soundnerd3886-2.gif (8.4 KB, 2988 views)
  Reply With Quote
Old 21st January 2004, 10:38 PM   #20
bbksv is offline bbksv  United States
diyAudio Member
 
Join Date: Dec 2003
Location: Antioch, Il
Hey bigP...would you mind sending me that eagle file to bbksv@comcast.net........pretty please...
  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
My First LM3886 GC samsagaz Chip Amps 49 29th June 2008 07:55 PM
Psu Lm3886 Mayday Chip Amps 29 29th April 2007 06:10 PM
Lm3886 Bpa Tombson Chip Amps 99 21st August 2006 12:04 PM
Are two separate lm3886 = 2*lm3886 in parallel or bridge mode rs1026 Chip Amps 11 21st October 2004 10:24 AM


New To Site? Need Help?

All times are GMT. The time now is 10:32 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