SMT resistor Nonlinearity

[martin griffith]

been thinking about changing an audio cct from through hole resistor
to SMT, and had a look at RS components, just to see what was
available eg 648 0689, a vishay part D...-CRCW
http://www.vishay.com/doc?20008

I didnt like a graph I found, nonlinearity on P3 of the above data
sheet. Is this typical of SMT R's. No measurement details are given

(I'm still trying to find a resistor company not owned by Vishay)





martin

"An eye for an eye makes the whole world blind"
Gandhi

 

[Stephan Goldstein]

In article <8vfk21lraip9qufmu6p4s0gp2h7hld8r3h@4ax.com>, martin griffith <martingriffithX@Xyahoo.co.uk> wrote:

been thinking about changing an audio cct from through hole resistor
to SMT, and had a look at RS components, just to see what was
available eg 648 0689, a vishay part D...-CRCW
http://www.vishay.com/doc?20008

I didnt like a graph I found, nonlinearity on P3 of the above data
sheet. Is this typical of SMT R's. No measurement details are given

(I'm still trying to find a resistor company not owned by Vishay)

Good luck. It seems to be their strategy to control the entire passive
components marketplace. They've been buying up companies for the
past several years!

martin

"An eye for an eye makes the whole world blind"
Gandhi

 

[Martin Riddle]

Try http://www.koaspeer.com/koa/index.html

Cheers

"martin griffith" <martingriffithX@Xyahoo.co.uk> wrote in message news:8vfk21lraip9qufmu6p4s0gp2h7hld8r3h@4ax.com...

been thinking about changing an audio cct from through hole resistor
to SMT, and had a look at RS components, just to see what was
available eg 648 0689, a vishay part D...-CRCW
http://www.vishay.com/doc?20008

I didnt like a graph I found, nonlinearity on P3 of the above data
sheet. Is this typical of SMT R's. No measurement details are given

(I'm still trying to find a resistor company not owned by Vishay)





martin

"An eye for an eye makes the whole world blind"
Gandhi

 

[Helmut Sennewald]

"martin griffith" <martingriffithX@Xyahoo.co.uk> schrieb im Newsbeitrag
news:8vfk21lraip9qufmu6p4s0gp2h7hld8r3h@4ax.com...

been thinking about changing an audio cct from through hole resistor
to SMT, and had a look at RS components, just to see what was
available eg 648 0689, a vishay part D...-CRCW
http://www.vishay.com/doc?20008

I didnt like a graph I found, nonlinearity on P3 of the above data
sheet. Is this typical of SMT R's. No measurement details are given

(I'm still trying to find a resistor company not owned by Vishay)

Hello Martin,
this is a very interesting datasheet with a lot of information.
I have searched for some definitions and found the following paper.
http://www.vishay.com/docs/20103/geninfo.pdf

Nonlinearity:
A3 = 20*log(U1/E3) [dB]
Measurements are according to IEC60440.

Who knows how big U1 is for this measurement?
Does anybody have IEC60440 and can look there?

Another bad thing is the current noise in the datasheet.
This noise can be bigger than the thermal noise in some cases.

Best Regards,
Helmut

 

[Active8]

On Sun, 06 Mar 2005 00:36:10 +0100, martin griffith wrote:
<snip>

(I'm still trying to find a resistor company not owned by Vishay)

What is it you don't like about Vishay? Save me the hell of finding
out the hard way?

--
Best Regards,
Mike

 

[John Woodgate]

I read in sci.electronics.design that martin griffith
<martingriffithX@Xyahoo.co.uk> wrote (in <8vfk21lraip9qufmu6p4s0gp2h7hld
8r3h@4ax.com&gt about 'SMT resistor Nonlinearity', on Sun, 6 Mar 2005:

been thinking about changing an audio cct from through hole resistor to
SMT, and had a look at RS components, just to see what was available eg
648 0689, a vishay part D...-CRCWhttp://www.vishay.com/doc?20008

I didnt like a graph I found, nonlinearity on P3 of the above data
sheet. Is this typical of SMT R's. No measurement details are given

The measurement details are probably in one or more of the standards
cited under 'Applicable Specifications' on the last page.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[martin griffith]

On Sun, 6 Mar 2005 00:53:10 -0500, in sci.electronics.design Active8
<reply2group@ndbbm.net> wrote:

On Sun, 06 Mar 2005 00:36:10 +0100, martin griffith wrote:
snip
(I'm still trying to find a resistor company not owned by Vishay)

What is it you don't like about Vishay? Save me the hell of finding
out the hard way?
It was trying to get through the distro's for relatvely small

quantites of sfernice pots a few years ago, and some stories I heard
from Barry Porter (RIP).

martin

"An eye for an eye makes the whole world blind"
Gandhi

 

[martin griffith]

On Sun, 6 Mar 2005 01:47:39 +0100, in sci.electronics.design "Helmut
Sennewald" <HelmutSennewald@t-online.de> wrote:

"martin griffith" <martingriffithX@Xyahoo.co.uk> schrieb im Newsbeitrag
news:8vfk21lraip9qufmu6p4s0gp2h7hld8r3h@4ax.com...
been thinking about changing an audio cct from through hole resistor
to SMT, and had a look at RS components, just to see what was
available eg 648 0689, a vishay part D...-CRCW
http://www.vishay.com/doc?20008

I didnt like a graph I found, nonlinearity on P3 of the above data
sheet. Is this typical of SMT R's. No measurement details are given

(I'm still trying to find a resistor company not owned by Vishay)


Hello Martin,
this is a very interesting datasheet with a lot of information.
I have searched for some definitions and found the following paper.
http://www.vishay.com/docs/20103/geninfo.pdf

Nonlinearity:
A3 = 20*log(U1/E3) [dB]
Measurements are according to IEC60440.

Who knows how big U1 is for this measurement?
Does anybody have IEC60440 and can look there?

Another bad thing is the current noise in the datasheet.
This noise can be bigger than the thermal noise in some cases.

Best Regards,
Helmut

Thanks, found it as well..

martin

"An eye for an eye makes the whole world blind"
Gandhi

 

[Robert Baer]

martin griffith wrote:

been thinking about changing an audio cct from through hole resistor
to SMT, and had a look at RS components, just to see what was
available eg 648 0689, a vishay part D...-CRCW
http://www.vishay.com/doc?20008

I didnt like a graph I found, nonlinearity on P3 of the above data
sheet. Is this typical of SMT R's. No measurement details are given

(I'm still trying to find a resistor company not owned by Vishay)





martin

"An eye for an eye makes the whole world blind"
Gandhi
Check out Xicon from Mouser if i remember correctly.

 

[martin griffith]

On Sun, 06 Mar 2005 10:14:23 GMT, in sci.electronics.design Robert
Baer <robertbaer@earthlink.net> wrote:

martin griffith wrote:

been thinking about changing an audio cct from through hole resistor
to SMT, and had a look at RS components, just to see what was
available eg 648 0689, a vishay part D...-CRCW
http://www.vishay.com/doc?20008

I didnt like a graph I found, nonlinearity on P3 of the above data
sheet. Is this typical of SMT R's. No measurement details are given

(I'm still trying to find a resistor company not owned by Vishay)





martin

"An eye for an eye makes the whole world blind"
Gandhi
Check out Xicon from Mouser if i remember correctly.
i've been checking Panasonic parts from digikey as well, but they dont

spec nonlinearity at the moment

martin

"An eye for an eye makes the whole world blind"
Gandhi

 

[Mike Monett]

Helmut Sennewald wrote:

[...]

Hello Martin,
this is a very interesting datasheet with a lot of information.
I have searched for some definitions and found the following paper.
http://www.vishay.com/docs/20103/geninfo.pdf

Nonlinearity:
A3 = 20*log(U1/E3) [dB]
Measurements are according to IEC60440.

Who knows how big U1 is for this measurement?
Does anybody have IEC60440 and can look there?

Another bad thing is the current noise in the datasheet.
This noise can be bigger than the thermal noise in some cases.

Best Regards,
Helmut

Helmut - isn't U1 the amplitude of the fundamental? From the description:

"The harmonic index is defined as the logarithm of the ratio
of the fundamental U1 to the 3rd harmonic E3. It is specified in dB"

The amplitude and frequency are probably specified in IEC 60440. I found a web page
with a free copy of the update to the spec, "IEC/TR 60440 Ed. 1.0 Cor.1 (Bilingual
1974) Corrigendum 1 - Method of measurement of non-linearity in resistors":

http://www.standards.com.au/Catalogue/Script/Details.asp?DocN=IEC70195121449

Registration is free. Their main page is

http://www.standards.com.au/Catalogue/Script/ICSDocBrowse.asp?Code=31.040&StdType=IEC
OTOH, maybe John W might have some info.

Regards,

Mike Monett

Mike Monett

 

[James Meyer]

On Sun, 06 Mar 2005 12:42:57 +0100, martin griffith
<martingriffithX@Xyahoo.co.uk> wroth:

i've been checking Panasonic parts from digikey as well, but they dont
spec nonlinearity at the moment

martin

"An eye for an eye makes the whole world blind"
Gandhi

You could measure the non-linearity of a few yourself. If you can't
measure it, then why does it concern you?

Jim

 

[martin griffith]

On Sun, 06 Mar 2005 18:06:34 GMT, in sci.electronics.design James
Meyer <jmeyer@nowhere.net> wrote:

On Sun, 06 Mar 2005 12:42:57 +0100, martin griffith
martingriffithX@Xyahoo.co.uk> wroth:


i've been checking Panasonic parts from digikey as well, but they dont
spec nonlinearity at the moment

martin

"An eye for an eye makes the whole world blind"
Gandhi

You could measure the non-linearity of a few yourself. If you can't
measure it, then why does it concern you?

Jim

thats what I'm thinking of doing.

make a AC driven wheatsone type bridge, with 3 precision resistors and
the smt DUT and if the bridge is balanced it should be easy(?) to
spot any non linear stuff.
That should cancel out any generator distortions shouldnt it?

any other options/methods?

martin

"An eye for an eye makes the whole world blind"
Gandhi

 

[James Meyer]

On Sun, 06 Mar 2005 19:58:29 +0100, martin griffith
<martingriffithX@Xyahoo.co.uk> wroth:

On Sun, 06 Mar 2005 18:06:34 GMT, in sci.electronics.design James
Meyer <jmeyer@nowhere.net> wrote:


You could measure the non-linearity of a few yourself. If you can't
measure it, then why does it concern you?

Jim

thats what I'm thinking of doing.
make a AC driven wheatsone type bridge, with 3 precision resistors and
the smt DUT and if the bridge is balanced it should be easy(?) to
spot any non linear stuff.
That should cancel out any generator distortions shouldnt it?

any other options/methods?

martin

Commercial measurement instruments use a high purity 10KHz source to
pass current through the resistor (resistor is grounded on one end). There is a
low pass filter between the source and the resistor. Next there is a 30KHz
filter and a detector. They measure the 30KHz third harmonic which is supposed
to be related to the resistor's non-linearity. It's not the best way I can
think of, but it's easy to do and if everybody does it the same way, then at
least measurements in the spec sheets are somewhat comparable.

http://www.hotektech.com/DanbridgeCLT1020.htm

and

http://www.simacelectronics.nl/content/downloads/danbridge/CLT10-SE.PDF

Jim

 

[Rich Grise]

On Sun, 06 Mar 2005 22:38:43 +0000, James Meyer wrote:

Commercial measurement instruments use a high purity 10KHz source to
pass current through the resistor (resistor is grounded on one end). There is a
low pass filter between the source and the resistor. Next there is a 30KHz
filter and a detector. They measure the 30KHz third harmonic which is supposed
to be related to the resistor's non-linearity.

Sure it is! To do an exaggerated example, do a Fourier transform on, say,
y = log(sin(x) + k). Pick any k that doesn't break the computer. ;-) Or
any non-linear transfer function.

Any kind of nonlinearity like that should show up as third harmonic, plus there'd
be others, depending on the shape of the transfer function.

Now I'm curious as heck what the spectrum looks like, but have no idea how to
do a Fourier transform. )-;

Thanks,
Rich

 

[John Woodgate]

I read in sci.electronics.design that Rich Grise <richgrise@example.net>
wrote (in <pan.2005.03.07.02.56.54.209677@example.net&gt about 'SMT
resistor Nonlinearity', on Mon, 7 Mar 2005:

On Sun, 06 Mar 2005 22:38:43 +0000, James Meyer wrote:

Commercial measurement instruments use a high purity 10KHz source to
pass current through the resistor (resistor is grounded on one end). There is
a
low pass filter between the source and the resistor. Next there is a 30KHz
filter and a detector. They measure the 30KHz third harmonic which is
supposed
to be related to the resistor's non-linearity.

Sure it is! To do an exaggerated example, do a Fourier transform on, say,
y = log(sin(x) + k). Pick any k that doesn't break the computer. ;-) Or
any non-linear transfer function.

Any kind of nonlinearity like that should show up as third harmonic, plus
there'd
be others, depending on the shape of the transfer function.

Now I'm curious as heck what the spectrum looks like, but have no idea how to
do a Fourier transform. )-;

For all n, multiply the function by exp(jnx) and integrate over any

range in x of 2pi. What could be simpler? (;-)
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[Ken Smith]

In article <pan.2005.03.07.02.56.54.209677@example.net>,
Rich Grise <richgrise@example.net> wrote:
[....]

filter and a detector. They measure the 30KHz third harmonic which is
supposed
to be related to the resistor's non-linearity.

Sure it is! To do an exaggerated example, do a Fourier transform on, say,
y = log(sin(x) + k). Pick any k that doesn't break the computer. ;-) Or
any non-linear transfer function.

Any kind of nonlinearity like that should show up as third harmonic,
plus there'd
be others, depending on the shape of the transfer function.

It is those others that may spell the downfall of this method of
specifying the distortion. Two resistors can look equally bad under this
test with one being much worse than the other. A flat spot as you pass
through zero can make the same amplitude 3rd harmonic as a smooth curve.

Now I'm curious as heck what the spectrum looks like, but have no idea how to
do a Fourier transform. )-;

I can think of four methods:

(1) For each frequency, multiply the signal by SIN(WT) and integrate to
get the SIN part. Do the same for the COS part.

(2) Use the kit for doing FFT in speadsheets.

(3) Make the curve in LTSpice and use the built in spectrum.

(4) Get a copy of the code for some FFT program and compile it.
--
--
kensmith@rahul.net forging knowledge

 

[John Woodgate]

I read in sci.electronics.design that Ken Smith
<kensmith@green.rahul.net> wrote (in <d0hqqe$fk8$1@blue.rahul.net&gt
about 'SMT resistor Nonlinearity', on Mon, 7 Mar 2005:

It is those others that may spell the downfall of this method of
specifying the distortion. Two resistors can look equally bad under
this test with one being much worse than the other. A flat spot as you
pass through zero can make the same amplitude 3rd harmonic as a smooth
curve.

It is possible but not very likely. For most passive non-linearities,
the third harmonic amplitude relative to the fundamental is a reliable
quality indicator. The harmonic spectra tend to be roughly monotonic,
decreasing in amplitude inversely proportional to order.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[Mark]

Then measure the second harmonic at 20 kHz if you would rather see the
even order distortion insead of the odd order distortion.

Mark

 

[Rich Grise]

On Mon, 07 Mar 2005 08:11:38 +0000, John Woodgate wrote:

I read in sci.electronics.design that Rich Grise <richgrise@example.net
....
Now I'm curious as heck what the spectrum looks like, but have no idea
how to do a Fourier transform. )-;

For all n, multiply the function by exp(jnx) and integrate over any
range in x of 2pi. What could be simpler? (;-)

Simpler? Uh, maybe, "Find your foot" or "Peek-A-Boo"? ;-)

Thanks,
Rich