Burnt my finger - OPA4134 - 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 21st March 2008, 02:14 PM   #1
diyAudio Member
 
Join Date: Aug 2006
Angry Burnt my finger - OPA4134

OK I'm making two sets of OP Amps for an input to a ADC and output from an DAC. I dont think I've over soldered them and i checked it many times before I powered them. The design I've used is the recomended from the datashhets of the ADC and the DAC, but they are getting extreamly hot. I rewired and tested a few of the seperate amp with a simple closed loop gain circuit and some of them have burnt out . I tryed simulating the design in multisim but its giving me errors. Take a look at my design, I'm not sure what I've done wrong .

DAC: http://www.ortodoxism.ro/datasheets/...ts/pcm1730.pdf

ADC: http://focus.ti.com/lit/ds/symlink/pcm1804.pdf

OPAMP: http://www.selectronic.fr/includes_s..._2134_4134.pdf

Thanks.
Attached Images
File Type: jpg op amps.jpg (82.9 KB, 547 views)
  Reply With Quote
Old 21st March 2008, 03:50 PM   #2
TheMG is offline TheMG  Canada
diyAudio Member
 
Join Date: Jan 2008
Chips heating up is usually a sign of the power supply being connected backwards or otherwise incorrectly.
  Reply With Quote
Old 21st March 2008, 04:23 PM   #3
KSTR is online now KSTR  Germany
diyAudio Member
 
KSTR's Avatar
 
Join Date: Jul 2007
Location: Central Berlin, Germany
The filter section (DAC part) is wired incorrectly. Take a closer look at Fig.7 in the DS and compare with what you have.

ADC is also wrong: You need a buffer/follower (1st OP), then an inverter (2nd OP), and both outputs of the buffer and the inverter feed their corresponding filter section (3rd and 4th OP), see DS Fig.44.

And, quite important: You must not leave opamps unconnected. Wire them as followers (OUT to -IN) and connect the input (+IN) to GND. Otherwise the might oscillate.

Do you have adequate power supply bypassing right at the chip?

- Klaus
  Reply With Quote
Old 21st March 2008, 10:00 PM   #4
diyAudio Member
 
Join Date: Aug 2006
I see what you mean. I don't know what I had drawn, must have got really mixed up somewhere. Also, would those incorrections have caused permanant dammage to the packages? The power supply i used was +/-12V connected correctly. I used a 25W iron with a 1mm tip, didnt take too long to solder, but for a few pins I had to apply about 6 seconds of heat to get the packages held down. I dont think that could have caused problems though.
  Reply With Quote
Old 22nd March 2008, 12:25 AM   #5
KSTR is online now KSTR  Germany
diyAudio Member
 
KSTR's Avatar
 
Join Date: Jul 2007
Location: Central Berlin, Germany
I assume you have the 4134 in the DIP14 package. Damage from soldering is rather unlikely (DS says 300C for 10sec), but one cannot know if the chips got damaged by the heatup during operation... so better use new chips for the next round.

- Klaus
  Reply With Quote
Old 23rd March 2008, 03:29 PM   #6
diyAudio Member
 
Join Date: Aug 2006
I used the SOIC-14 surface mount chips I soldered on to a DIP adaptor, I have a couple spare so I'll try again.
  Reply With Quote
Old 11th April 2008, 07:18 PM   #7
diyAudio Member
 
Join Date: Aug 2006
Ok Burnt my finger again , I've made a new design however U4C (See diagram) seems to be oscillating, I've simulated the circuit and it seems to be fine, but i can't figure out whats wrong.
Attached Images
File Type: jpg opa4134 output_002.jpg (95.6 KB, 254 views)
  Reply With Quote
Old 11th April 2008, 08:41 PM   #8
diyAudio Member
 
theAnonymous1's Avatar
 
Join Date: Feb 2004
Location: Anonymityville
Quote:
Originally posted by KSTR
Do you have adequate power supply bypassing right at the chip?

- Klaus
You never answered Klaus in regards to your supply bypassing. This could be an issue.
  Reply With Quote
Old 11th April 2008, 11:11 PM   #9
diyAudio Member
 
Join Date: Aug 2006
Yes the supply is fine, the other amps on the chip work, it's just the last one.
  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
OPA4134 x TL074 - Sound Differences -_nando-_ Chip Amps 41 25th December 2013 03:50 PM
Tl074, Opa4134, Lme49740 ztan Solid State 4 23rd October 2013 07:12 PM
Paging Mr. Pass, Mr. Pass pull my finger please. khundude Pass Labs 2 5th December 2008 04:11 AM
Finger joints vs. screw and glue PRNDL Tubes / Valves 35 21st November 2006 12:24 AM
Finger Cellular Phone Netlist Digital Source 8 14th November 2003 09:01 PM


New To Site? Need Help?

All times are GMT. The time now is 02:49 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