LM4780TA (Non Insulated Type) - 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 7th April 2011, 07:45 PM   #1
diyAudio Member
 
Join Date: Jul 2004
Location: Singapore
Default LM4780TA (Non Insulated Type)

hi guys,
take look at the back of the chips (LM4780TA)
the metal plate seem tarnish. is this normal?

Click the image to open in full size.

same goes for LM4702CTA
Click the image to open in full size.

thank you.

Last edited by JustinMarker; 7th April 2011 at 08:02 PM.
  Reply With Quote
Old 7th April 2011, 08:24 PM   #2
diyAudio Member
 
Join Date: Jul 2004
Location: Singapore
shoudl be more careful with word.
i mean non-isolated
  Reply With Quote
Old 7th April 2011, 08:44 PM   #3
diyAudio Member
 
Join Date: Sep 2010
I doubt anything is wrong with them. As long as you got them from a legit supplier that you know supplies authentic chips, don't worry about it. I have plenty of ICs laying around with similar "tarnish". If it's bothering you, get some rubbing alcohol and a Q-tip.
  Reply With Quote
Old 7th April 2011, 08:49 PM   #4
diyAudio Member
 
Join Date: Sep 2010
Though the casing on the second ones do look a little odd...
  Reply With Quote
Old 8th April 2011, 12:41 AM   #5
diyAudio Member
 
Join Date: Jul 2004
Location: Singapore
hi,
yes i got it from a legit supplier locally.
thanks for the assurance.

the casing on the second one are from LM4702CTA.

anyone from the semiconductor packaging industry please do help to comment from the manufacturing point of view.

thank you.
  Reply With Quote
Old 8th April 2011, 04:36 PM   #6
diyAudio Member
 
pmbrunelle's Avatar
 
Join Date: Sep 2005
Location: Montréal, Canada
I wouldn't try much aggressive cleaning of the heat transfer surface.

If you're going too aggressive with sandpaper or a file or something, while you'll make the surface shiny, it's easy to take off more material from the edges, and make a convex surface with less effective heat transfer area.

Maybe some steel wool, but it looks pretty normal to my eye.
  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
insulated turret terminals arend-jan Tubes / Valves 32 15th November 2009 01:17 PM
FS: LM3886TF and LM4780TA merv Swap Meet 1 29th May 2009 02:23 AM
Lm4702Cta & Lm4780ta gengis Swap Meet 1 24th October 2007 10:12 PM
LM4780TA For Sale or Trade DSchmidt Swap Meet 0 22nd December 2005 12:31 AM
Paralleled LM4780TA PC board design - How's this look? OddOne Chip Amps 17 4th May 2004 01:21 AM


New To Site? Need Help?

All times are GMT. The time now is 09:00 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