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Re: Another op-amp stability question (LT1677)

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Am 30.03.2017 um 02:14 schrieb John Miles, KE5FX:
> On Wednesday, March 29, 2017 at 2:29:23 PM UTC-7, Gerhard Hoffmann wrote:
>> There is a 49R9 termination resistor from Pin3 to gnd.
>>
>
> Thanks, that seems to be a good clue.  I was mistaken when I said the
> source Z "didn't matter" -- I must not have tried anything very low.
> Can you take the 49.9 ohm termination out, and add a 10K series
> resistance from the function generator instead?  Set the 3325B to
> 50 Hz, 1V peak, 1V offset, and run the LT1677 from +5V.  See if it
> looks like this:
>
> http://www.ke5fx.com/3325B_1Vpk_1Voff_10K_series_R_Vcc5.png
>
> When I use a termination under a couple K, the instability goes away.
>
> -- john, KE5FX
>


Hi, John,

you have found a real bug with the LT1677 !

< 
https://www.flickr.com/photos/137684711@N07/33598135802/in/album-72157662535945536/ 
 >

cheers,

Gerhard, DK4XP

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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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