Forums

Zener Q

Started by Robert Baer 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 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
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 chip-stack the way they made them, had virtually zero TC. But I could be remembering wrong... that was 40 years ago :-) ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | 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 160 North State Road #203 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 >chip-stack the way they made them, had virtually zero TC. > >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 Innovations, Inc. | et | | 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