Re: [volt-nuts] ADA4522

2016-04-09 Thread Bruce Griffiths 
Why?The ADA4522 is unity gain stable with about 60 degrees of phase margin.The 
equivalent output inductance at unity gain is about 0.5u
 50 ohms in series with the 1uF output capacitance ensures an overdamped 
response.

Bruce
On Saturday, 9 April 2016 11:20 PM, "acb...@gmx.de" <acb...@gmx.de> wrote:
 

 not sure the TI filter circuitry, although very nice, is stable with the 
ADA4522. 
have not checked, but R2/C2 loop stabilizer may not work with ad4522.
would require analysis/test, but positive result would sure make this a great 
reference buffer amp.
if you do, would be nice if you let the group know.



> Gesendet: Samstag, 09. April 2016 um 00:38 Uhr
> Von: "Randy Evans" <randyevans2...@gmail.com>
> An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> Betreff: Re: [volt-nuts] ADA4522
>
> I would use a filter such as TI's SBVA010 app note, "Improved Voltage
> reference Filter has Several Advanatages" or the article by Walt Jung,
> "Build an Ultra-Low Noise Voltage Reference" in Electronic Design.
> 
> On Fri, Apr 8, 2016 at 1:02 AM, <acb...@gmx.de> wrote:
> 
> > Low frequency noise is very good, but is is high noise at about 800kHz
> > (chopper) and above (possible artifacts). That should be filtered,
> > depending on your application.
> > What did you foresee to get rid of it, or would you accept it? Simple RC
> > filter as indicated in the manual increases the output resistance.
> >
> >
> >
> >
> > > Gesendet: Freitag, 08. April 2016 um 03:35 Uhr
> > > Von: "Randy Evans" <randyevans2...@gmail.com>
> > > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> > > Betreff: Re: [volt-nuts] ADA4522
> > >
> > > Sure, all good applications.  I am thinking of using it as an output
> > filter
> > > for a 10V reference to filter all noise above 10Hz,
> > >
> > > On Thu, Apr 7, 2016 at 6:27 PM, Daniel Mendes <dmend...@gmail.com>
> > wrote:
> > >
> > > > Ada4522-2 and 4522-4 are stocked at mouser. What about summing all
> > outputs
> > > > to reduce noise? Or use as buffered outputs with good reverse
> > isolation...
> > > >
> > > > Daniel
> > > > Em 07/04/2016 13:31, "Randy Evans" <randyevans2...@gmail.com>
> > escreveu:
> > > >
> > > > > Has anyone looked at the ADA4522 precision op amp from Analog
> > Devices.
> > > > It
> > > > > looks very intriguing with it's extremely low offset voltage drift
> > of 22
> > > > > nV/°C maximum.  The offset voltage is as high as 5 uV but this could
> > be
> > > > > nulled out and it should be very stable over temperature after
> > that.  It
> > > > > could be a great choice for a voltage reference circuit.  Looks quite
> > > > > inexpensive also, although AD only sell in tubes of 96 right now.
> > > > > ___
> > > > > volt-nuts mailing list -- volt-nuts@febo.com
> > > > > To unsubscribe, go to
> > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > > > > and follow the instructions there.
> > > > >
> > > > ___
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> > > > To unsubscribe, go to
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> > > > and follow the instructions there.
> > > >
> > > ___
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> > > To unsubscribe, go to
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> > > and follow the instructions there.
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> >
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Re: [volt-nuts] ADA4522

2016-04-09 Thread acbern 
not sure the TI filter circuitry, although very nice, is stable with the 
ADA4522. 
have not checked, but R2/C2 loop stabilizer may not work with ad4522.
would require analysis/test, but positive result would sure make this a great 
reference buffer amp.
if you do, would be nice if you let the group know.



> Gesendet: Samstag, 09. April 2016 um 00:38 Uhr
> Von: "Randy Evans" <randyevans2...@gmail.com>
> An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> Betreff: Re: [volt-nuts] ADA4522
>
> I would use a filter such as TI's SBVA010 app note, "Improved Voltage
> reference Filter has Several Advanatages" or the article by Walt Jung,
> "Build an Ultra-Low Noise Voltage Reference" in Electronic Design.
> 
> On Fri, Apr 8, 2016 at 1:02 AM, <acb...@gmx.de> wrote:
> 
> > Low frequency noise is very good, but is is high noise at about 800kHz
> > (chopper) and above (possible artifacts). That should be filtered,
> > depending on your application.
> > What did you foresee to get rid of it, or would you accept it? Simple RC
> > filter as indicated in the manual increases the output resistance.
> >
> >
> >
> >
> > > Gesendet: Freitag, 08. April 2016 um 03:35 Uhr
> > > Von: "Randy Evans" <randyevans2...@gmail.com>
> > > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> > > Betreff: Re: [volt-nuts] ADA4522
> > >
> > > Sure, all good applications.  I am thinking of using it as an output
> > filter
> > > for a 10V reference to filter all noise above 10Hz,
> > >
> > > On Thu, Apr 7, 2016 at 6:27 PM, Daniel Mendes <dmend...@gmail.com>
> > wrote:
> > >
> > > > Ada4522-2 and 4522-4 are stocked at mouser. What about summing all
> > outputs
> > > > to reduce noise? Or use as buffered outputs with good reverse
> > isolation...
> > > >
> > > > Daniel
> > > > Em 07/04/2016 13:31, "Randy Evans" <randyevans2...@gmail.com>
> > escreveu:
> > > >
> > > > > Has anyone looked at the ADA4522 precision op amp from Analog
> > Devices.
> > > > It
> > > > > looks very intriguing with it's extremely low offset voltage drift
> > of 22
> > > > > nV/°C maximum.  The offset voltage is as high as 5 uV but this could
> > be
> > > > > nulled out and it should be very stable over temperature after
> > that.  It
> > > > > could be a great choice for a voltage reference circuit.  Looks quite
> > > > > inexpensive also, although AD only sell in tubes of 96 right now.
> > > > > ___
> > > > > volt-nuts mailing list -- volt-nuts@febo.com
> > > > > To unsubscribe, go to
> > > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > > > > and follow the instructions there.
> > > > >
> > > > ___
> > > > volt-nuts mailing list -- volt-nuts@febo.com
> > > > To unsubscribe, go to
> > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > > > and follow the instructions there.
> > > >
> > > ___
> > > volt-nuts mailing list -- volt-nuts@febo.com
> > > To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > > and follow the instructions there.
> > >
> > ___
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> > To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > and follow the instructions there.
> >
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Re: [volt-nuts] ADA4522

2016-04-08 Thread Randy Evans 
I would use a filter such as TI's SBVA010 app note, "Improved Voltage
reference Filter has Several Advanatages" or the article by Walt Jung,
"Build an Ultra-Low Noise Voltage Reference" in Electronic Design.

On Fri, Apr 8, 2016 at 1:02 AM, <acb...@gmx.de> wrote:

> Low frequency noise is very good, but is is high noise at about 800kHz
> (chopper) and above (possible artifacts). That should be filtered,
> depending on your application.
> What did you foresee to get rid of it, or would you accept it? Simple RC
> filter as indicated in the manual increases the output resistance.
>
>
>
>
> > Gesendet: Freitag, 08. April 2016 um 03:35 Uhr
> > Von: "Randy Evans" <randyevans2...@gmail.com>
> > An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> > Betreff: Re: [volt-nuts] ADA4522
> >
> > Sure, all good applications.  I am thinking of using it as an output
> filter
> > for a 10V reference to filter all noise above 10Hz,
> >
> > On Thu, Apr 7, 2016 at 6:27 PM, Daniel Mendes <dmend...@gmail.com>
> wrote:
> >
> > > Ada4522-2 and 4522-4 are stocked at mouser. What about summing all
> outputs
> > > to reduce noise? Or use as buffered outputs with good reverse
> isolation...
> > >
> > > Daniel
> > > Em 07/04/2016 13:31, "Randy Evans" <randyevans2...@gmail.com>
> escreveu:
> > >
> > > > Has anyone looked at the ADA4522 precision op amp from Analog
> Devices.
> > > It
> > > > looks very intriguing with it's extremely low offset voltage drift
> of 22
> > > > nV/°C maximum.  The offset voltage is as high as 5 uV but this could
> be
> > > > nulled out and it should be very stable over temperature after
> that.  It
> > > > could be a great choice for a voltage reference circuit.  Looks quite
> > > > inexpensive also, although AD only sell in tubes of 96 right now.
> > > > ___
> > > > volt-nuts mailing list -- volt-nuts@febo.com
> > > > To unsubscribe, go to
> > > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > > > and follow the instructions there.
> > > >
> > > ___
> > > volt-nuts mailing list -- volt-nuts@febo.com
> > > To unsubscribe, go to
> > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > > and follow the instructions there.
> > >
> > ___
> > volt-nuts mailing list -- volt-nuts@febo.com
> > To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > and follow the instructions there.
> >
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Re: [volt-nuts] ADA4522

2016-04-08 Thread acbern 
Low frequency noise is very good, but is is high noise at about 800kHz 
(chopper) and above (possible artifacts). That should be filtered, depending on 
your application. 
What did you foresee to get rid of it, or would you accept it? Simple RC filter 
as indicated in the manual increases the output resistance.




> Gesendet: Freitag, 08. April 2016 um 03:35 Uhr
> Von: "Randy Evans" <randyevans2...@gmail.com>
> An: "Discussion of precise voltage measurement" <volt-nuts@febo.com>
> Betreff: Re: [volt-nuts] ADA4522
>
> Sure, all good applications.  I am thinking of using it as an output filter
> for a 10V reference to filter all noise above 10Hz,
> 
> On Thu, Apr 7, 2016 at 6:27 PM, Daniel Mendes <dmend...@gmail.com> wrote:
> 
> > Ada4522-2 and 4522-4 are stocked at mouser. What about summing all outputs
> > to reduce noise? Or use as buffered outputs with good reverse isolation...
> >
> > Daniel
> > Em 07/04/2016 13:31, "Randy Evans" <randyevans2...@gmail.com> escreveu:
> >
> > > Has anyone looked at the ADA4522 precision op amp from Analog Devices.
> > It
> > > looks very intriguing with it's extremely low offset voltage drift of 22
> > > nV/°C maximum.  The offset voltage is as high as 5 uV but this could be
> > > nulled out and it should be very stable over temperature after that.  It
> > > could be a great choice for a voltage reference circuit.  Looks quite
> > > inexpensive also, although AD only sell in tubes of 96 right now.
> > > ___
> > > volt-nuts mailing list -- volt-nuts@febo.com
> > > To unsubscribe, go to
> > > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > > and follow the instructions there.
> > >
> > ___
> > volt-nuts mailing list -- volt-nuts@febo.com
> > To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> > and follow the instructions there.
> >
> ___
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> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> and follow the instructions there.
>
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Re: [volt-nuts] ADA4522

2016-04-07 Thread Daniel Mendes 
Ada4522-2 and 4522-4 are stocked at mouser. What about summing all outputs
to reduce noise? Or use as buffered outputs with good reverse isolation...

Daniel
Em 07/04/2016 13:31, "Randy Evans"  escreveu:

> Has anyone looked at the ADA4522 precision op amp from Analog Devices.  It
> looks very intriguing with it's extremely low offset voltage drift of 22
> nV/°C maximum.  The offset voltage is as high as 5 uV but this could be
> nulled out and it should be very stable over temperature after that.  It
> could be a great choice for a voltage reference circuit.  Looks quite
> inexpensive also, although AD only sell in tubes of 96 right now.
> ___
> volt-nuts mailing list -- volt-nuts@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> and follow the instructions there.
>
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[volt-nuts] ADA4522

2016-04-07 Thread Randy Evans 
Has anyone looked at the ADA4522 precision op amp from Analog Devices.  It
looks very intriguing with it's extremely low offset voltage drift of 22
nV/°C maximum.  The offset voltage is as high as 5 uV but this could be
nulled out and it should be very stable over temperature after that.  It
could be a great choice for a voltage reference circuit.  Looks quite
inexpensive also, although AD only sell in tubes of 96 right now.
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