Anyone ever do anything with the TI opa 548? - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
Thread Tools Search this Thread
Old 20th January 2003, 07:13 PM   #1
Account Disabled
Join Date: Dec 2002
Default Anyone ever do anything with the TI opa 548?

It is made by BB/TI, and looks to be pretty decent. Has anyone ever tried to make an amp using this?

  Reply With Quote
Old 20th January 2003, 07:18 PM   #2
joensd is offline joensd  Germany
diyAudio Member
Join Date: Dec 2001
Location: Germany
Hi Paul,
just received some samples of that kind.
There is a application note for an amplifier called "complete audio amplifier" from Burr Brown (TI). Its with tone control but you can leave that out if you want to.
A lot of people use it for power supplies as well.

  Reply With Quote
Old 24th January 2003, 11:11 PM   #3
ppl is offline ppl  United States
diyAudio Member
ppl's Avatar
Join Date: Apr 2001
Location: Seattle, WA U.S.A.
Default Nice Battery Powered 10 Watt Amp

I made a small stereo amp using a pair of OPA-548,s in Bridge mode. with 8 ohm and above Loudspeakers I have used 6 ohm ratt shack LS-5's at one time and it worked but the Hammond 1455 series exturded aluminium case got real warm almost hot. The case also serving as a common heatsink for all (4) OPA-548's. The reproduction is alot better than the Car stereo IC power Amp Chips, althought the Car IC's do power lower impedance loads better.

Topology wise the OPA-548 is more akin to your nomal Op Amp than the Car stereo IC that most often has rail to rail single supply and an all NPN output stage. The OPA-548 on the other hand uses a true differential Input and Complimentry Output Emitter follower output stage both of these i am strongly in favor of and the Complimentry output stage of the OPA-548 is a futher Bonus in Bridged applications where Both the Advantages of an ALL NPN output stage and Complementry symmectrical output stage transistor Pairs all in one.

The attractive aspect of the OPA-548 vs your typical Car stereo IC is First a Bridged stereo amp will have about 80 mA quesent curent and work op to 30 volt supplys. The Car stereo IC stereo Amp will require about 300 mA. The low voltage operation is similar to car stereo IC's with a 7-8 volt min. however, the Max on the 548 is about twice that of a Car IC @ 30 Volts.

In coclusion I am happy with its use as a small light weight High Quality Stereo Amplifier. would also be great in Powered loudspeakers desireing Battery opation.
  Reply With Quote
Old 4th May 2003, 09:22 PM   #4
diyAudio Member
colwaiting's Avatar
Join Date: Dec 2002
Location: boston Ma.
Default ppl

Yes- although this is an old thread, I just posted on the 548 & was encouraged by your info. I had not dissected the internals of TI's product, but I can say with certainty that the 3886T is a quasi-complementary beastie. I have not been impressed W/ the sound, tube like or not. The TI does cost more money, BTW.

I am led to wonder about a car circuit that could produce -(that's minus) 14.2V, which is a running car, +/-. It could be ballasted by a small batt (to say nothing about boomer caps) and the result would be decent at 4 ohms without bridging. These chips could be paralled for reliability, and heat-sinkery.
I realize this puts us into the murky world of mosfet switchers , but can't the folks here come up with just about anything?
  Reply With Quote
Old 5th May 2003, 11:11 PM   #5
diyAudio Moderator
pinkmouse's Avatar
Join Date: Apr 2002
Location: Rotherham, England
I know nothing about switching PSUs, but I have made about 14 channels worth of 458, using various inverted versions, and I think it is one of the nicest amps I have ever heard, better than the usual LMs any day

If anyone wants a pcb layout, one I did is here.
Rick: Oh Cliff / Sometimes it must be difficult not to feel as if / You really are a cliff / when fascists keep trying to push you over it! / Are they the lemmings / Or are you, Cliff? / Or are you Cliff?
  Reply With Quote
Old 6th May 2003, 07:41 PM   #6
diyAudio Member
Matttcattt's Avatar
Join Date: Feb 2003
Location: Bristol
yes, i made a stereo amp with them before i made my OPA541 amp that i am working on at the moment. they were ok, im no audiophile so i dont have an opinion on sound quality :P
If it aint broke, don't fix it. If it is broke, fix it.
If you can't fix it, take it apart and see how it "worked".
  Reply With Quote
Old 7th May 2003, 12:47 AM   #7
EJ is offline EJ
diyAudio Member
Join Date: Jun 2002
Location: PA
One advantage of OPA548 over 3886/3875 is that it is unity-gain stable while the datasheets of 3886/3875 said their voltage gain cannot be less than 10.
  Reply With Quote


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

New To Site? Need Help?

All times are GMT. The time now is 07:05 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2