# Zener Q

Started by August 30, 2012
```   Which voltage has the lowest average temperature coefficient (say 20C
to +40C): 4.7V or 5.1V?
"Average" is to mean a sample of 150 from hundreds of thousands.

Is there a variation of the average TC between parts from wafer to
wafer, and how much?

Ref: Vishay MMBZ230, MMBZ5231.
```
```Robert Baer <robertbaer@localnet.com> wrote:

>   Which voltage has the lowest average temperature coefficient (say 20C
>to +40C): 4.7V or 5.1V?
>   "Average" is to mean a sample of 150 from hundreds of thousands.

IIRC traditionally that is 6.2V or 6.8V. Check the datasheet to make
sure.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------
```
```On 31 Aug., 00:11, n...@puntnl.niks (Nico Coesel) wrote:
> Robert Baer <robertb...@localnet.com> wrote:
> > =A0 Which voltage has the lowest average temperature coefficient (say 2=
0C
> >to +40C): 4.7V or 5.1V?
> > =A0 "Average" is to mean a sample of 150 from hundreds of thousands.
>
> IIRC traditionally that is 6.2V or 6.8V. Check the datasheet to make
> sure.
>

from what I've read zero is supposed to be around 5V

the slightly higher voltages might be a zener and diode in series so
the positive and
negative coefficient balance out

-Lasse
```
```On 8/30/2012 2:41 PM, Robert Baer wrote:
> Which voltage has the lowest average temperature coefficient (say 20C to
> +40C): 4.7V or 5.1V?
> "Average" is to mean a sample of 150 from hundreds of thousands.
>
> Is there a variation of the average TC between parts from wafer to
> wafer, and how much?
>
> Ref: Vishay MMBZ230, MMBZ5231.

ON the very first day of my very first engineering job, my mentor
took me aside and informed me that I could trust what it said
on the data sheet some of the time.
Selected parts were a no-no.

I once had to clean up after an engineer who'd used a selected part.
It was part numbered.  There were a kagillion of 'em in stock.
And it was dirt cheap compared to the alternatives.

Nobody bothered to check and learn that the project that had
company was out of business.  We learned the hard way when
both production lines shut down.

http://www.maxim-ic.com/app-notes/index.mvp/id/2879

```
```On Thu, 30 Aug 2012 22:11:28 GMT, nico@puntnl.niks (Nico Coesel)
wrote:

>Robert Baer <robertbaer@localnet.com> wrote:
>
>>   Which voltage has the lowest average temperature coefficient (say 20C
>>to +40C): 4.7V or 5.1V?
>>   "Average" is to mean a sample of 150 from hundreds of thousands.
>
>IIRC traditionally that is 6.2V or 6.8V. Check the datasheet to make
>sure.

I think you're mixing standard versus compensated.

Thinking back to my days at Dickson Electronics, I made hybrid
circuits, the other half of the building made TC'd zeners... if I'm
remembering correctly 5.6V + a diode drop = 6.2V, physically a

But I could be remembering wrong... that was 40 years ago :-)

...Jim Thompson
--
| James E.Thompson, CTO                            |    mens     |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |

I love to cook with wine.     Sometimes I even put it in the food.
```
```mike wrote:
>
> On 8/30/2012 2:41 PM, Robert Baer wrote:
> > Which voltage has the lowest average temperature coefficient (say 20C to
> > +40C): 4.7V or 5.1V?
> > "Average" is to mean a sample of 150 from hundreds of thousands.
> >
> > Is there a variation of the average TC between parts from wafer to
> > wafer, and how much?
> >
> > Ref: Vishay MMBZ230, MMBZ5231.
>
> ON the very first day of my very first engineering job, my mentor
> took me aside and informed me that I could trust what it said
> on the data sheet some of the time.
> Selected parts were a no-no.
>
> I once had to clean up after an engineer who'd used a selected part.
> It was part numbered.  There were a kagillion of 'em in stock.
> And it was dirt cheap compared to the alternatives.
>
> Nobody bothered to check and learn that the project that had
> specified the part had bought a lifetime supply and that the
> company was out of business.  We learned the hard way when
> both production lines shut down.
>
> http://www.maxim-ic.com/app-notes/index.mvp/id/2879

I really like LM329s, but they don't come in SMT and there's some worry
that they may go away.  I usually put in a population option, so that
the 329 can be replaced with something like an LT1021-7.  Those are a
lot more money, and no better for most of my uses, but if the 329 goes
away, no board spin is required.

Cheers

Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net
```
```On Thu, 30 Aug 2012 15:27:44 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

>On Thu, 30 Aug 2012 22:11:28 GMT, nico@puntnl.niks (Nico Coesel)
>wrote:
>
>>Robert Baer <robertbaer@localnet.com> wrote:
>>
>>>   Which voltage has the lowest average temperature coefficient (say 20C
>>>to +40C): 4.7V or 5.1V?
>>>   "Average" is to mean a sample of 150 from hundreds of thousands.
>>
>>IIRC traditionally that is 6.2V or 6.8V. Check the datasheet to make
>>sure.
>
>I think you're mixing standard versus compensated.
>
>Thinking back to my days at Dickson Electronics, I made hybrid
>circuits, the other half of the building made TC'd zeners... if I'm
>remembering correctly 5.6V + a diode drop = 6.2V, physically a
>
>But I could be remembering wrong... that was 40 years ago :-)
>
>                                        ...Jim Thompson

Just also remembering that, on a single bipolar process, that 5.6V +
TWO Vbe's, made a nearly flat 7V.... that's what is in most of my
alternator regulator patents.

...Jim Thompson
--
| James E.Thompson, CTO                            |    mens     |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |

I love to cook with wine.     Sometimes I even put it in the food.
```
```On Thu, 30 Aug 2012 14:41:13 -0700, Robert Baer
<robertbaer@localnet.com> wrote:

>   Which voltage has the lowest average temperature coefficient (say 20C
>to +40C): 4.7V or 5.1V?

Depends on the operating current. 5.6 may be better.

Use a bandgap!

--

John Larkin         Highland Technology, Inc

jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser drivers and controllers
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro   acquisition and simulation
```
```On Thu, 30 Aug 2012 18:34:43 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>mike wrote:
>>
>> On 8/30/2012 2:41 PM, Robert Baer wrote:
>> > Which voltage has the lowest average temperature coefficient (say 20C to
>> > +40C): 4.7V or 5.1V?
>> > "Average" is to mean a sample of 150 from hundreds of thousands.
>> >
>> > Is there a variation of the average TC between parts from wafer to
>> > wafer, and how much?
>> >
>> > Ref: Vishay MMBZ230, MMBZ5231.
>>
>> ON the very first day of my very first engineering job, my mentor
>> took me aside and informed me that I could trust what it said
>> on the data sheet some of the time.
>> Selected parts were a no-no.
>>
>> I once had to clean up after an engineer who'd used a selected part.
>> It was part numbered.  There were a kagillion of 'em in stock.
>> And it was dirt cheap compared to the alternatives.
>>
>> Nobody bothered to check and learn that the project that had
>> specified the part had bought a lifetime supply and that the
>> company was out of business.  We learned the hard way when
>> both production lines shut down.
>>
>> http://www.maxim-ic.com/app-notes/index.mvp/id/2879
>
>I really like LM329s, but they don't come in SMT and there's some worry
>that they may go away.  I usually put in a population option, so that
>the 329 can be replaced with something like an LT1021-7.  Those are a
>lot more money, and no better for most of my uses, but if the 329 goes
>away, no board spin is required.
>
>Cheers
>
>Phil Hobbs

Why not use an LM4040/4041 or some such?

--

John Larkin         Highland Technology, Inc

jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser drivers and controllers
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro   acquisition and simulation
```
```On Aug 30, 11:41=A0pm, Robert Baer <robertb...@localnet.com> wrote:
> =A0 =A0Which voltage has the lowest average temperature coefficient (say =
20C
> to +40C): 4.7V or 5.1V?
> =A0 =A0"Average" is to mean a sample of 150 from hundreds of thousands.
>
> =A0 =A0Is there a variation of the average TC between parts from wafer to
> wafer, and how much?
>
> =A0 =A0Ref: Vishay MMBZ230, MMBZ5231.

Motorola made a lot of money selling the the 1N823 - 1N829 series

http://www.datasheetcatalog.org/datasheet/motorola/1N823.pdf

which is a 5.6V zener in series with a regular diode.

5.6V is far enough out of the Zener breakdown region and close enough
to the avalanche region that positive temperature coefficient of the
Zener diode was as predictable and stable as the negative temperature
coefficient of the forward drop across the regular diode.

If they could have done as well with a 5.1V zener on its own, I don't
think that they would have bothered inventing the 1N823 series.

--
Bill Sloman, Nijmegen
```