Crossreference for a AD542KH?

J

JW

Guest
Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:
http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.

Thanks.
 
JW wrote:

Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:
http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.

Thanks.
You most likely won't find one in that package how ever, if you google
Click to expand...
PRECISION op-amps., you'll fine many that actually have much better
spec's than what you're looking for and you can simply adapt one on the
board, if this is just a repair problem..

We have done this many times, replacing those older types of IC's with
newer types that have far lower offsets and noise figures. It usually
ends up with a better overall operating device.

P.S.
If this IC is part of a balanced circuit (i.e., kelvin bridge),
you'll need to replace both.
 
On Sat, 18 Jul 2009 10:12:48 -0400, JW <none@dev.nul>wrote:

Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:
http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.

Thanks.
Click to expand...
AD544/AD547/AD548. Yours is in a tin can, replacements will be an 8
pin DIP.

Dual version you might be able to use as single - AD642/647?
 
On Sat, 18 Jul 2009 11:03:12 -0400 Jamie
<jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in Message id:
<Ujl8m.23646$qM4.19587@newsfe01.iad>:

JW wrote:

Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:
http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.

Thanks.
You most likely won't find one in that package how ever, if you google
PRECISION op-amps., you'll fine many that actually have much better
spec's than what you're looking for and you can simply adapt one on the
board, if this is just a repair problem..

We have done this many times, replacing those older types of IC's with
newer types that have far lower offsets and noise figures. It usually
ends up with a better overall operating device.
Click to expand...
Hi Jamie,

That wouldn't be a problem. But I'm not sure what I should replace it
*with* unfortunately. Never was any good at picking a good sub. :(
It is located in a HP 3478A 5.5 digit DMM, location U101, on the main
board in the current source circuit.
http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=722603&lc=eng&cc=US&nfr=-11143.0.00
Warning: it is 10.4MB if anybody is on dial-up.


P.S.
If this IC is part of a balanced circuit (i.e., kelvin bridge),
you'll need to replace both.
Click to expand...
Nope, it's not.

Thanks.
 
JW wrote:

On Sat, 18 Jul 2009 11:03:12 -0400 Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in Message id:
Ujl8m.23646$qM4.19587@newsfe01.iad>:


JW wrote:


Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:
http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.

Thanks.

You most likely won't find one in that package how ever, if you google
PRECISION op-amps., you'll fine many that actually have much better
spec's than what you're looking for and you can simply adapt one on the
board, if this is just a repair problem..

We have done this many times, replacing those older types of IC's with
newer types that have far lower offsets and noise figures. It usually
ends up with a better overall operating device.


Hi Jamie,

That wouldn't be a problem. But I'm not sure what I should replace it
*with* unfortunately. Never was any good at picking a good sub. :(
It is located in a HP 3478A 5.5 digit DMM, location U101, on the main
board in the current source circuit.
http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=722603&lc=eng&cc=US&nfr=-11143.0.00
Warning: it is 10.4MB if anybody is on dial-up.



P.S.
If this IC is part of a balanced circuit (i.e., kelvin bridge),
you'll need to replace both.


Nope, it's not.

Thanks.
INA121PA
Click to expand...

Try that, Its found at mouser.com, the offset voltage isn't as good
as the original but it's very close. I would say the important part of
it's operation that you need actually out spec's the original.
 
On Sat, 18 Jul 2009 18:37:13 -0400 Jamie
<jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in Message id:
<0_r8m.20889$ZN.65@newsfe23.iad>:

[...]

Hi Jamie,

That wouldn't be a problem. But I'm not sure what I should replace it
*with* unfortunately. Never was any good at picking a good sub. :(
It is located in a HP 3478A 5.5 digit DMM, location U101, on the main
board in the current source circuit.
http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=722603&lc=eng&cc=US&nfr=-11143.0.00
Warning: it is 10.4MB if anybody is on dial-up.



P.S.
If this IC is part of a balanced circuit (i.e., kelvin bridge),
you'll need to replace both.


Nope, it's not.

Thanks.
INA121PA

Try that, Its found at mouser.com, the offset voltage isn't as good
as the original but it's very close. I would say the important part of
it's operation that you need actually out spec's the original.
Click to expand...
OK, I'll give that one a try. Should I leave pins 1 and 8 disconnected for
gain of 1? The original device didn't have these pins...

Thanks again.
 
On Sat, 18 Jul 2009 18:37:13 -0400, Jamie
<jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:

JW wrote:

On Sat, 18 Jul 2009 11:03:12 -0400 Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in Message id:
Ujl8m.23646$qM4.19587@newsfe01.iad>:


JW wrote:


Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:
http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.

Thanks.

You most likely won't find one in that package how ever, if you google
PRECISION op-amps., you'll fine many that actually have much better
spec's than what you're looking for and you can simply adapt one on the
board, if this is just a repair problem..

We have done this many times, replacing those older types of IC's with
newer types that have far lower offsets and noise figures. It usually
ends up with a better overall operating device.


Hi Jamie,

That wouldn't be a problem. But I'm not sure what I should replace it
*with* unfortunately. Never was any good at picking a good sub. :(
It is located in a HP 3478A 5.5 digit DMM, location U101, on the main
board in the current source circuit.
http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=722603&lc=eng&cc=US&nfr=-11143.0.00
Warning: it is 10.4MB if anybody is on dial-up.



P.S.
If this IC is part of a balanced circuit (i.e., kelvin bridge),
you'll need to replace both.


Nope, it's not.

Thanks.
INA121PA

Try that, Its found at mouser.com, the offset voltage isn't as good
as the original but it's very close. I would say the important part of
it's operation that you need actually out spec's the original.
Click to expand...
I'd be careful about that. AD542 is an OPamp. INA121 is an INamp.
They are very different in function.

Have you tried crossing it on ADI's web site? I'm sure they have
something comparable or better in the present catalog, though
as another poster has said, possibly not in the metal can package.
 
On Sun, 19 Jul 2009 07:09:15 -0400 Stephan Goldstein
<sgoldHAM@alum.mit.edu> wrote in Message id:
<ujv565lgu9u58mmfkjkhlpvbo9ptsr0sju@4ax.com>:

[...]

I'd be careful about that. AD542 is an OPamp. INA121 is an INamp.
They are very different in function.

Have you tried crossing it on ADI's web site? I'm sure they have
something comparable or better in the present catalog, though
as another poster has said, possibly not in the metal can package.
Click to expand...
Hi Stephan,

Yes, I did try to see if their web page would offer up a sub, but it
offers the AD544 and AD547 which are also obsolete. Thanks though.
 
In sci.electronics.components JW <none@dev.nul> wrote:
Hello,

Was wondering if someone might be able to suggest a
cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:
http://search.analog.com/search/default.aspx?query=AD542..

This is used as part of a resistance current circuit
source for a HP 3478A 5.5 digit DMM.
Click to expand...
What voltage do you need? If the supply is smaller then 16 Volt, the AD8638
might be an option.
--
Uwe Bonnes bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------
 
On Jul 18, 10:12 am, JW <n...@dev.nul> wrote:
Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.
Click to expand...
But, what are the power supplies connected to? A true drop-in
replacement if it takes +/-18V is going to be hard; if your
power supply is +/- 5V it gets easier. Using a 'cross
reference' will not find options that meet only SOME of
the specs, even if that would suit your application nicely.
 
JW wrote:

On Sat, 18 Jul 2009 18:37:13 -0400 Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in Message id:
0_r8m.20889$ZN.65@newsfe23.iad>:

[...]


Hi Jamie,

That wouldn't be a problem. But I'm not sure what I should replace it
*with* unfortunately. Never was any good at picking a good sub. :(
It is located in a HP 3478A 5.5 digit DMM, location U101, on the main
board in the current source circuit.
http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=722603&lc=eng&cc=US&nfr=-11143.0.00
Warning: it is 10.4MB if anybody is on dial-up.




P.S.
If this IC is part of a balanced circuit (i.e., kelvin bridge),
you'll need to replace both.


Nope, it's not.

Thanks.

INA121PA

Try that, Its found at mouser.com, the offset voltage isn't as good
as the original but it's very close. I would say the important part of
it's operation that you need actually out spec's the original.


OK, I'll give that one a try. Should I leave pins 1 and 8 disconnected for
gain of 1? The original device didn't have these pins...

Thanks again.
You need to set the gain at max. use R around the 5K region.
Click to expand...

There is an issue here how ever, I don't know if you have +/- supply
with reference to common? I can only assume that you do, in which case,
the REF pin needs to be on the common, not the (-) rail.

After you have done that, the device should behave like your original.
---
I've just did another look at your PDF file of your meter and the
op-amp you're using.

I do think a AD743 would be more particle for you even though the
input current is alittle higher. The data sheet does
not give a warm up time and drift how ever, in your application it may
not matter.

If you want to stick with older technology that is still being used
out there for the Bifet family..

The LF355/6/7, if you employ the balance circuit they show, it'll get
you to the input offset equal to what you need how ever, you may not
even need to do this. It's also possible you may still find in some old
stock the can packages which are pin for pin compatible.

It's just a matter of how exact you want the chip to be like the
original when it comes to stability in settling time and drift. I really
don't think you'll have issues for your needs.


Personally, I would experiment with the LF355/6/7 family and see how it
does. It don't cost that much so it's not like you're losing your
shirt tail.
 
On Sun, 19 Jul 2009 09:57:31 -0700 (PDT) whit3rd <whit3rd@gmail.com> wrote
in Message id:
<580f88e4-1858-490b-bff8-abe5fa3cb10a@d4g2000yqa.googlegroups.com>:

On Jul 18, 10:12 am, JW <n...@dev.nul> wrote:
Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.

But, what are the power supplies connected to? A true drop-in
replacement if it takes +/-18V is going to be hard; if your
power supply is +/- 5V it gets easier. Using a 'cross
reference' will not find options that meet only SOME of
the specs, even if that would suit your application nicely.
Click to expand...
The supply in this circuit is +/- 15V.
Thanks.
 
On Sun, 19 Jul 2009 07:25:58 -0400, JW <none@dev.nul> wrote:

On Sun, 19 Jul 2009 07:09:15 -0400 Stephan Goldstein
sgoldHAM@alum.mit.edu> wrote in Message id:
ujv565lgu9u58mmfkjkhlpvbo9ptsr0sju@4ax.com>:

[...]

I'd be careful about that. AD542 is an OPamp. INA121 is an INamp.
They are very different in function.

Have you tried crossing it on ADI's web site? I'm sure they have
something comparable or better in the present catalog, though
as another poster has said, possibly not in the metal can package.

Hi Stephan,

Yes, I did try to see if their web page would offer up a sub, but it
offers the AD544 and AD547 which are also obsolete. Thanks though.
Click to expand...
Do you have room to fit a plastic DIP with the proper adapter or
wiring? This will open up a much larger universe of potential
replacement parts. It may well be that the metal can package is
obsolete, but not others (I'll check when I get to work). As this
is an instrument you probably don't need the wide temperature
range, but simply the specs of the K version. (K is electrical grade,
H is metal-can package).

It's possible, though, that the metal can provides some shielding.
You won't get this with a plastic pack.

How many do you need. Perhaps I can find one in a drawer
somewhere. Send me an email, but remove the upper-case food
item first!
 
On Sat, 18 Jul 2009 10:12:48 -0400, JW <none@dev.nul> wrote:

Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:
http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.

Thanks.
Click to expand...
I have a couple of AD542KH sitting on my desk right now. They are
datecode 8517, but have never been used as far as I can tell, and
have always been stored in a controlled (lab) environment. Part of
the secret stash...

Where shall I send them? Send me an email. To do so, you will
need to remove the uppercase letters from the indicated posting
address. Hint - there are three such.

Steve
 
On Mon, 20 Jul 2009 19:28:22 -0400 Stephan Goldstein
<sgoldHAM@alum.mit.edu> wrote in Message id:
<27v9651dfbsilo8oeour7jrosqdbr9uoca@4ax.com>:

On Sat, 18 Jul 2009 10:12:48 -0400, JW <none@dev.nul> wrote:

Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:
http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.

Thanks.

I have a couple of AD542KH sitting on my desk right now. They are
datecode 8517, but have never been used as far as I can tell, and
have always been stored in a controlled (lab) environment. Part of
the secret stash...

Where shall I send them? Send me an email. To do so, you will
need to remove the uppercase letters from the indicated posting
address. Hint - there are three such.

Steve
Click to expand...
Hello Steve,

Check your email, and thank you very much!

Jay
 
On Sat, 18 Jul 2009 11:23:15 -0400 Meat Plow <meat@petitmorte.net> wrote
in Message id: <2vpeu7.ef8.17.3@news.alt.net>:

On Sat, 18 Jul 2009 10:12:48 -0400, JW <none@dev.nul>wrote:

Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:
http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.

Thanks.

AD544/AD547/AD548. Yours is in a tin can, replacements will be an 8
pin DIP.
Click to expand...
AFAIK, that wouldn't be a problem... But I could be wrong.

Dual version you might be able to use as single - AD642/647?
Click to expand...
Luckily Stephan has offered to send me one. Thanks for your help, though!
 
On Tue, 21 Jul 2009 06:13:09 -0400, JW <none@dev.null>wrote:

On Sat, 18 Jul 2009 11:23:15 -0400 Meat Plow <meat@petitmorte.net> wrote
in Message id: <2vpeu7.ef8.17.3@news.alt.net>:

On Sat, 18 Jul 2009 10:12:48 -0400, JW <none@dev.nul>wrote:

Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:
http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.

Thanks.

AD544/AD547/AD548. Yours is in a tin can, replacements will be an 8
pin DIP.

AFAIK, that wouldn't be a problem... But I could be wrong.
Click to expand...
It's not a problem, I've done it a few times using a DIP socket.

Dual version you might be able to use as single - AD642/647?

Luckily Stephan has offered to send me one. Thanks for your help, though!
Click to expand...
Good you'll get something very close to specs and you might just be
able to calibrate it back to factory.
 
Stephan Goldstein wrote:

On Sat, 18 Jul 2009 10:12:48 -0400, JW <none@dev.nul> wrote:


Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:
http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.

Thanks.


I have a couple of AD542KH sitting on my desk right now. They are
datecode 8517, but have never been used as far as I can tell, and
have always been stored in a controlled (lab) environment. Part of
the secret stash...

Where shall I send them? Send me an email. To do so, you will
need to remove the uppercase letters from the indicated posting
address. Hint - there are three such.

Steve
Nice guy you are :)
Click to expand...
 
On Wed, 22 Jul 2009 13:17:54 -0400, Jamie
<jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:

Stephan Goldstein wrote:

On Sat, 18 Jul 2009 10:12:48 -0400, JW <none@dev.nul> wrote:


Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:
http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.

Thanks.


I have a couple of AD542KH sitting on my desk right now. They are
datecode 8517, but have never been used as far as I can tell, and
have always been stored in a controlled (lab) environment. Part of
the secret stash...

Where shall I send them? Send me an email. To do so, you will
need to remove the uppercase letters from the indicated posting
address. Hint - there are three such.

Steve
Nice guy you are :)
Click to expand...
Those AD542s were never going to get used, the last time
we used them in a test fixture or breadboard was over 20
years ago. I'm glad they could be of use to someone.

Maybe some day you'll be able to do the same for me or
someone else.
 
Stephan Goldstein wrote:

On Wed, 22 Jul 2009 13:17:54 -0400, Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:


Stephan Goldstein wrote:


On Sat, 18 Jul 2009 10:12:48 -0400, JW <none@dev.nul> wrote:



Hello,

Was wondering if someone might be able to suggest a cross reference for a
Analog Devices AD542KH which is long obsolete?
Datasheet:
http://search.analog.com/search/default.aspx?query=AD542KH&local=en

This is used as part of a resistance current circuit source for a HP 3478A
5.5 digit DMM.

Thanks.


I have a couple of AD542KH sitting on my desk right now. They are
datecode 8517, but have never been used as far as I can tell, and
have always been stored in a controlled (lab) environment. Part of
the secret stash...

Where shall I send them? Send me an email. To do so, you will
need to remove the uppercase letters from the indicated posting
address. Hint - there are three such.

Steve

Nice guy you are :)




Those AD542s were never going to get used, the last time
we used them in a test fixture or breadboard was over 20
years ago. I'm glad they could be of use to someone.

Maybe some day you'll be able to do the same for me or
someone else.
Click to expand...
Well, thanks for the offer, we too have a collection of the older
CAN type packages we bought out a few years ago to keep our aging RDI
equipment working.

Our facility still has in operation the very first, ever built,
irradiation unit for x-linking of ployrads etc.. This unit still is
using much of it's original electronics. The chemical engineering of the
first X linking compounds were also developed at the facility..

Of course, the world has grown and every one and their brother has
this process now :)
 
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