will this work properly? - 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 29th July 2006, 08:26 PM   #1
diyAudio Member
 
Join Date: Aug 2004
Location: Blenheim - New Zealand
Send a message via MSN to ELiTeHaYDeN
Default will this work properly?

Hi there, maybe this time with a more respectable layout/labelled/circuit made from - i might get a better response..

hows this look?

also what hole size do you guys use for the lm4780, and what pad width?

in my latest attempt i tried to go for a design where theres minimal crossing of output and input, power etc

this was made up using the Reference PCB Schematic.

Reference Circuit

My PCB

I still need to add a bridge rectifier
__________________
mMmMmmMmmk?
  Reply With Quote
Old 29th July 2006, 08:49 PM   #2
Bazukaz is offline Bazukaz  Lithuania
diyAudio Member
 
Bazukaz's Avatar
 
Join Date: Nov 2005
Location: Vilnius
Send a message via Skype™ to Bazukaz
Hi,
It is probably OK , but i would like to point few things.If you are going to use separate main supply caps , you must connect high current grounds(Outputs , capacitor centers) and low level grounds(inputs , feedback , etc) with separate wires to main capacitor block ground.Otherwise , slight hums , or even something more serious may appear , because high currents flowing from outputs and to recharge bypass caps would induce voltages into low signal gound.
Another thing is that you should bypass 1000uF caps with 47-100nF ceramics , as close to IC as possible.

Regards,
Lukas.
  Reply With Quote
Old 29th July 2006, 09:01 PM   #3
diyAudio Member
 
Join Date: Aug 2004
Location: Blenheim - New Zealand
Send a message via MSN to ELiTeHaYDeN
yeah i forgot to add a small cap across the power supply

so you mean, basically remove that green link connecting the input ground to the main ground, put in another pad, and run that ground indiviually back to the main caps?
__________________
mMmMmmMmmk?
  Reply With Quote
Old 29th July 2006, 09:02 PM   #4
diyAudio Member
 
Join Date: Dec 2001
Location: SIUE, Illinois, USA
notes:

1.) will you be wanting to attach this to a heatsink? if so, maybe move the caps to a location that isn't directly in front of the screws' mountpoints.

2.) do you have plated through holes? it may be difficult to solder top layer connections in some places such as under the 68uF cap.

3.) while note required, it is generally best to have the PCB made with the IC at the edge of the board so it can be flush with a heatsink, and require no spacers or such.

4.) the connections are mostly in odd places on the PCB. will this be an issue?
__________________
if only it could be used for good, not evil...
  Reply With Quote
Old 29th July 2006, 09:12 PM   #5
diyAudio Member
 
Join Date: Aug 2004
Location: Blenheim - New Zealand
Send a message via MSN to ELiTeHaYDeN
Quote:
Originally posted by theChris
notes:

1.) will you be wanting to attach this to a heatsink? if so, maybe move the caps to a location that isn't directly in front of the screws' mountpoints.

2.) do you have plated through holes? it may be difficult to solder top layer connections in some places such as under the 68uF cap.

3.) while note required, it is generally best to have the PCB made with the IC at the edge of the board so it can be flush with a heatsink, and require no spacers or such.

4.) the connections are mostly in odd places on the PCB. will this be an issue?
1). Yes thanks for mentioning that, I will move the caps over a bit.

2). No, it wont be plated through holes, thats why i have attempted to make as little connections as possible via the top layer, i have yet to further see how I can reduce it, it should not be too bigger deal to solder the top layer tho, ive done it before on same sort of ic's

3) It is dead on flush with the back of the chip and the edge of the board, obvisoully that image is not to scale. (4.5mm from the centre of the back pins to the edge of the board, i need to shave about another 7-8mm off to make sure its a clean fit.

4) I think it will still be easy to make it neat,

Keep the suggestions coming thanks guys.
__________________
mMmMmmMmmk?
  Reply With Quote
Old 29th July 2006, 09:13 PM   #6
Bazukaz is offline Bazukaz  Lithuania
diyAudio Member
 
Bazukaz's Avatar
 
Join Date: Nov 2005
Location: Vilnius
Send a message via Skype™ to Bazukaz
Quote:
Originally posted by ELiTeHaYDeN
yeah i forgot to add a small cap across the power supply

so you mean, basically remove that green link connecting the input ground to the main ground, put in another pad, and run that ground indiviually back to the main caps?
Right.
  Reply With Quote
Old 30th July 2006, 04:46 AM   #7
diyAudio Member
 
Join Date: Dec 2001
Location: SIUE, Illinois, USA
1.) if the chip is exactly flush, i reccomend attaching the heatsink and IC before soldering. if you don't you can end up with the IC at an angle, or a bit further in then you had hoped.

2.) the 68uF cap has connections to the top layer. it may be difficult to solder to the leads of this device on both the top and bottom layers -- the cap will be sitting on top of the lead. it looks like you can route this connection from elsewhere on that net and connect to ground without vias.

you can also move the top layer trace from 8-9 to the bottom. pins 1,3,5 can connect on bottom. 12-19 can be on bottom, but a connection to 12-13 (13 is unused right?) would allow you to route this net to ground on the bottom layer, clearing up the under-chip area for the A input to move to pin 16 on the bottom layer, under the chip -- which gets rid of the via on Vee.

this leaves top layer connections only for Vcc, and you can use jumpers to move to a single layer PCB if needed.

there are other small things, like widening some traces or filling in some area for aesthetics or better connection.

pic included -- i forgot to show the 8-9 connection on bottom, but such would be preferable.
Attached Images
File Type: png latestattemptc.png (80.9 KB, 84 views)
__________________
if only it could be used for good, not evil...
  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
Is my WT3 working properly? pp173 Multi-Way 6 22nd July 2008 02:39 PM
how to ground properly? Denis.BR Chip Amps 4 27th March 2007 07:17 PM
Art of Properly Grounding jawbreak Chip Amps 4 27th November 2004 07:39 PM
Will 6 ohm tweeter work properly with 8 ohm components? dih1118 Multi-Way 7 21st September 2003 12:18 AM


New To Site? Need Help?

All times are GMT. The time now is 01:32 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