Groups > sci.electronics.design > #454148

Re: Another op-amp stability question (LT1677)

From	Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de>
Newsgroups	sci.electronics.design
Subject	Re: Another op-amp stability question (LT1677)
Date	2017-03-29 23:29 +0200
Message-ID	<ek2n9fFgfd0U1@mid.individual.net> (permalink)
References	<28246daf-fd57-48e6-a94e-2e778c9a3973@googlegroups.com> <e2fd268f-5754-48eb-8232-16be73682874@googlegroups.com> <6d0867fc-d6ff-4f88-ab0f-a232486b05e5@googlegroups.com>

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Am 29.03.2017 um 19:58 schrieb John Miles, KE5FX:
> On Wednesday, March 29, 2017 at 4:50:57 AM UTC-7, pcdh...@gmail.com wrote:
>> Where's the supply bypass? First guess is that 100 nF to ground will fix it.
>
> Big glass-encapsulated axial ceramic in photo.  I think it's 330 nF but it
> might be 100.  Makes no difference.
>
> -- john, KE5FX
>

I have just built and tested it.
The setup is in

< 
https://www.flickr.com/photos/137684711@N07/32912433303/in/dateposted-public/ 
 >

I used a HP3325B as signal source, 500 Hz +- .
The built-in offset voltage is nice here.
There is a 49R9 termination resistor from Pin3 to gnd.

No problems whatsoever with Vcc from 3 to 15V.
But with Vcc < 2.4V hell breaks loose.
You can get any distortion or oscillation you can imagine
by just playing with the voltages.

But the spec says 3V min, so that is ok.

regards, Gerhard

Thread

Another op-amp stability question (LT1677) "John Miles, KE5FX" <jmiles@gmail.com> - 2017-03-29 00:37 -0700
  Another op-amp stability question (LT1677) pcdhobbs@gmail.com - 2017-03-29 04:50 -0700
    Re: Another op-amp stability question (LT1677) piglet <erichpwagner@hotmail.com> - 2017-03-29 13:23 +0100
    Re: Another op-amp stability question (LT1677) "John Miles, KE5FX" <jmiles@gmail.com> - 2017-03-29 10:58 -0700
      Re: Another op-amp stability question (LT1677) tabbypurr@gmail.com - 2017-03-29 11:15 -0700
      Re: Another op-amp stability question (LT1677) Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> - 2017-03-29 23:29 +0200
        Re: Another op-amp stability question (LT1677) "John Miles, KE5FX" <jmiles@gmail.com> - 2017-03-29 17:14 -0700
          Re: Another op-amp stability question (LT1677) "John Miles, KE5FX" <jmiles@gmail.com> - 2017-03-29 18:06 -0700
          Re: Another op-amp stability question (LT1677) Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> - 2017-03-31 14:40 +0200
            Re: Another op-amp stability question (LT1677) "John Miles, KE5FX" <jmiles@gmail.com> - 2017-03-31 14:49 -0700
              Re: Another op-amp stability question (LT1677) Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-03-31 20:39 -0400
              Re: Another op-amp stability question (LT1677) tabbypurr@gmail.com - 2017-04-01 09:16 -0700
                Re: Another op-amp stability question (LT1677) "John Miles, KE5FX" <jmiles@gmail.com> - 2017-04-01 15:03 -0700
                Re: Another op-amp stability question (LT1677) Winfield Hill <hill@rowland.harvard.edu> - 2017-04-01 16:46 -0700
                Re: Another op-amp stability question (LT1677) John Larkin <jjlarkin@highlandtechnology.com> - 2017-04-01 17:31 -0700
                Re: Another op-amp stability question (LT1677) tabbypurr@gmail.com - 2017-04-01 20:59 -0700
                Re: Another op-amp stability question (LT1677) "John Miles, KE5FX" <jmiles@gmail.com> - 2017-04-01 21:41 -0700
                Re: Another op-amp stability question (LT1677) tabbypurr@gmail.com - 2017-04-02 04:53 -0700
                Re: Another op-amp stability question (LT1677) John S <Sophi.2@invalid.org> - 2017-04-02 16:26 -0500
                Re: Another op-amp stability question (LT1677) krw@notreal.com - 2017-04-02 19:29 -0400
                Re: Another op-amp stability question (LT1677) John S <Sophi.2@invalid.org> - 2017-04-02 18:34 -0500
  Re: Another op-amp stability question (LT1677) John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-29 05:18 -0700
    Re: Another op-amp stability question (LT1677) "John Miles, KE5FX" <jmiles@gmail.com> - 2017-03-29 10:56 -0700
      Re: Another op-amp stability question (LT1677) John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-29 13:02 -0700
        Re: Another op-amp stability question (LT1677) "John Miles, KE5FX" <jmiles@gmail.com> - 2017-03-29 17:57 -0700
          Re: Another op-amp stability question (LT1677) John S <Sophi.2@invalid.org> - 2017-04-02 16:31 -0500
      Re: Another op-amp stability question (LT1677) John Larkin <jjlarkin@highlandtechnology.com> - 2017-04-15 08:58 -0700

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