|
I have been testing RAMTRON FRAM (Ferroelectric non-Volatile) devices
in a 2430A and so far the results are excellent. Anyone who has
worked on the 2430A, 2432A and 2440 (later models) knows that many of
the Dallas Semiconductor RAM/Battery modules are failing. The
Lithium power source is rated for 10 years of life. They seem to be
lasting 15 to 20 years, but that's it. When these parts fail the
scope loses its calibration data and other data.
I found this new class of device called a FRAM by searching for non-
volatile memory. I reviewed the datasheets and the design
considerations are slightly different than a regular SRAM or battery
backed SRAM. However depeding on the design it may be just a plug-in
equivalent.
Here is a case study from JPL on FRAM technology:
cs/16/16_namkung_p.pdf
The part I have tested in the 2430A is the RAMTRON FRAM FM1808-70-PG,
available at www.mouser.com.
Datasheet:
So far my testing in a 2430A shows that it can be used in a 2430A. I
will continue testing for at least a month. I am not concerned about
data retention and/or writing, I am concerned about the sequence of
events that occur during power down or loss of power.
The purpose of my post is to let everyone know that there may be a
possible (superior) alternative to the DS1230AB (or DS1235). No more
lithium batteries to fail!
The 2465A/B use a smaller battery backed RAM, the 8Kx8. If someone
is interested in testing the 8Kx8 FRAM in a 2465B it is the RAMTRON
FRAM FM1608-120-PG. Mouser Electronics has them for less than $6.
Datasheet:
Just to recap, the 32Kx8 FRAM device is showing great promise in a
2430A. I have done NO testing at all of the 8Kx8 device in a
2465B/45B. I leave that to someone here. If anyone does test please
report the results.
--Victor Silva
|
I have installed a RAMTRON FRAM FM1608-120-PG device in a 2465B
(socketed in case it didn't work). So far it works beautifully. I had
to perform all CAL procedures since the device was blank.
I suppose if a scope has valid calibration data in the NVRAM it could
be copied over to the new FRAM using an EPROM programmer that supports
RAM (many do).
The scope I put the FRAM in needed calibration anyways.
So far everything is working great.
--Victor
|
At 2:08 AM +0000 2006/12/30, Victor Silva wrote: I have installed a RAMTRON FRAM FM1608-120-PG device in a 2465B Thank you for brightening my day! md
|
Great to hear. Cast out those batteries! Something with a 10 year life
doesn't belong in a Tek scope. Tektronix made a mistake in my opinion
using these Dallas Lithium NVRAMs. I've designed equipment that
required non-volatile RAM and I've always done it by using standby RAM
and a coin style cell (like CR2032).
Any design that uses the Dallas devices is accepting the fact that the
equipment will be garbage in ten years.
--Victor
|
Those little Dallas chips were a godsend when they came out.
All you had to do to give a computer with a x8 CMOS ram some
nonvolatile memory was stick one in. No worries! The problems
with EEPROM's CS and /WR leads being indeterminate during power
down (and causing precious data to be overwritten with garbabe)
were not a problem with the Dallas chips... Some even came with
built in real time clocks.
I think tektronix made a wise decision in using the Dallas chips.
When they go bad, yank it out, and put in a new one. A socket is
a good idea. The scope is certain to require recalibration long before
the Dallas chip's battery expires. I have had EPROMS that didn't
last as long as the Dallas chips.
Now, a place where tektronix made a really poor battery/cell decision
was in the 1240 logic analyzers. There they used a pacemaker cell to
handle nonvolatile memory. When those cells go bad, they explode, and
spray boiling hot caustic electrolyte all over the place! To give the
devil it's due, the pacemaker cell maker recommended replacement every
5-10 years, and the damage takes 20+ years to develop.
-Chuck Harris
Victor Silva wrote:
toggle quoted message
Show quoted text
Great to hear. Cast out those batteries! Something with a 10 year life doesn't belong in a Tek scope. Tektronix made a mistake in my opinion using these Dallas Lithium NVRAMs. I've designed equipment that required non-volatile RAM and I've always done it by using standby RAM and a coin style cell (like CR2032).
Any design that uses the Dallas devices is accepting the fact that the equipment will be garbage in ten years.
--Victor
|
This is very interesting and a great news, thanks for sharing!
Didier KO4BB
Victor Silva wrote:
toggle quoted message
Show quoted text
I have installed a RAMTRON FRAM FM1608-120-PG device in a 2465B (socketed in case it didn't work). So far it works beautifully. I had to perform all CAL procedures since the device was blank.
I suppose if a scope has valid calibration data in the NVRAM it could be copied over to the new FRAM using an EPROM programmer that supports RAM (many do).
The scope I put the FRAM in needed calibration anyways.
So far everything is working great.
--Victor
|
I have found that the FRAM devices are not a viable option in the
243X/40. Sadly I must report that what looked like a very promising
alternative to the DALLAS RAM/Lithium cell combo has turned out to be
a dead end.
I have been testing for over one month now on a 2430A, 2440 and 2465B
and everything seemed fine. My last test was to actually determine
the read/write frequency to the device.
It turn out a 2430A writes to the battery-backed devices as often as
once every microsecond. Since the FRAM device as a maximum of 10^10
read/write cycles (before it loses its NV capability) a quick
calculation reveals that the 2430A scope will render the FRAM device
a volatile device in one to three months.
For now I can only recommend the DALLAS (or other vendors)
RAM/Lithium cell combo pack device for use in Tek scopes.
Sorry for getting everyone's hopes up for a more inexpensive
replacement for NVRAM.
--Victor Silva
|
Sounds like the whole RAM is battery-backed, not just the address space used
to hold calibration constants and instrument state. Is it practical to
Dremel the Dallas part open and replace its integral lithium cell with an
outboard cell?
-- john, KE5FX
toggle quoted message
Show quoted text
I have found that the FRAM devices are not a viable option in the
243X/40. Sadly I must report that what looked like a very promising
alternative to the DALLAS RAM/Lithium cell combo has turned out to be
a dead end.
I have been testing for over one month now on a 2430A, 2440 and 2465B
and everything seemed fine. My last test was to actually determine
the read/write frequency to the device.
It turn out a 2430A writes to the battery-backed devices as often as
once every microsecond. Since the FRAM device as a maximum of 10^10
read/write cycles (before it loses its NV capability) a quick
calculation reveals that the 2430A scope will render the FRAM device
a volatile device in one to three months.
For now I can only recommend the DALLAS (or other vendors)
RAM/Lithium cell combo pack device for use in Tek scopes.
Sorry for getting everyone's hopes up for a more inexpensive
replacement for NVRAM.
--Victor Silva
|
"John Miles" <jmiles@...> wrote: Sounds like the whole RAM is battery-backed, not just the address space used
to hold calibration constants and instrument state. Is it practical to
Dremel the Dallas part open and replace its integral lithium cell with an
outboard cell? It wouldn't be the first time something like that has been done: Not Dallas, but it's the same idea. -ls-
|
Be very careful here. There's a reason the Postal Service will not even ship Lithium cells and it is illegal to ship them via air cargo. If you happen to dremel into the cell, not only are you getting the caustic material flung all over, the cell will most likely short- circuit when it is cut into. Lithium cells can start fires if they are shorted. ST has equivalents to the DS devices used in both the 2465B and the 243X/40. The ST devices are slightly lower priced. ST Micro 8Kx8 DS1225AB equiv. M48Z58Y-70PC1 ST Micro 32Kx8 DS1230 (DS1235) equiv. M48Z35Y-70PC1 --Victor --- In TekScopes@..., "John Miles" <jmiles@...> wrote: Is it practical to
Dremel the Dallas part open and replace its integral lithium cell with an outboard cell?
-- john, KE5FX
|
Well, what fun would it be otherwise? Heh...
Would be nice if someone could X-ray one of those puppies to determine where
the cell actually is. But the equivalent part numbers are even more useful;
thanks for posting those.
-- john, KE5FX
toggle quoted message
Show quoted text
-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...]On
Behalf Of Victor Silva
Sent: Monday, February 05, 2007 1:54 PM
To: TekScopes@...
Subject: [TekScopes] Re: Replacement to DS1230AB Lithium backed NVRAM
Be very careful here. There's a reason the Postal Service will not
even ship Lithium cells and it is illegal to ship them via air cargo.
If you happen to dremel into the cell, not only are you getting the
caustic material flung all over, the cell will most likely short-
circuit when it is cut into. Lithium cells can start fires if they
are shorted.
ST has equivalents to the DS devices used in both the 2465B and the
243X/40. The ST devices are slightly lower priced.
ST Micro 8Kx8 DS1225AB equiv. M48Z58Y-70PC1
ST Micro 32Kx8 DS1230 (DS1235) equiv. M48Z35Y-70PC1
--Victor
--- In TekScopes@..., "John Miles" <jmiles@...> wrote:
Is it practical to
Dremel the Dallas part open and replace its integral lithium cell with an
outboard cell?
-- john, KE5FX
Yahoo! Groups Links
|
ST pioneered built-in battery backed up SRAMs with their MK48Z products many
years ago.
The Dallas parts were interesting inside. Seemed to work OK but I'm betting
most of the engineers in this group wouldn't have been happy with the sloppy
pre-encapsulation construction techniques (through-hole components on a PCB
in those days).
Eventually a third vendor, Benchmarq (later bought by Texas Instruments),
introduced their version of the products.
For a long time, ST offered the only Surface Mount version (heat from reflow
soldering plus coin cell battery was a bad combination). They came up with
their SnapHat product where the the battery (can't remember if any of the
control electronics are in it as well) is "snapped" onto the surface
mountable main portion of the component after the soldering process is
complete, etc. Maxim/Dallas now has their PowerCap version. I assume TI
has something similar.
A couple of other approaches:
Use a Dallas Smartsocket. Has the battery backup and associated electronics
in an IC Socket. One adds the low power SRAM of one's choice.
Simtek offers non-volatile SRAM products which don't require a battery.
During power-up the data in the non-volatile memory is written to SRAM and
vice-versa during power down. The rest of the time one is reading/writing
to the SRAM so the wear out issue present in the attempted Ramtron solution
is not present. Their current product offering is vastly improved over
their older product offering. Their original fab, ZMD, eventually produced
their own competing products for sale and later sold that portion of their
memory business to Simtek. Gave them products with increased densities and
SRAM compatible footprints.
- Greg
_____
From: TekScopes@... [mailto:TekScopes@...] On Behalf
Of John Miles
Sent: Monday, February 05, 2007 4:00 PM
To: TekScopes@...
Subject: RE: [TekScopes] Re: Replacement to DS1230AB Lithium backed NVRAM
Well, what fun would it be otherwise? Heh...
Would be nice if someone could X-ray one of those puppies to determine where
the cell actually is. But the equivalent part numbers are even more useful;
thanks for posting those.
-- john, KE5FX
toggle quoted message
Show quoted text
-----Original Message-----
From: TekScopes@yahoogrou <mailto:TekScopes%40yahoogroups.com> ps.com [mailto:TekScopes@yahoogrou <mailto:TekScopes%40yahoogroups.com> ps.com]On Behalf Of Victor Silva
Sent: Monday, February 05, 2007 1:54 PM
To: TekScopes@yahoogrou <mailto:TekScopes%40yahoogroups.com> ps.com
Subject: [TekScopes] Re: Replacement to DS1230AB Lithium backed NVRAM
Be very careful here. There's a reason the Postal Service will not
even ship Lithium cells and it is illegal to ship them via air cargo.
If you happen to dremel into the cell, not only are you getting the
caustic material flung all over, the cell will most likely short-
circuit when it is cut into. Lithium cells can start fires if they
are shorted.
ST has equivalents to the DS devices used in both the 2465B and the
243X/40. The ST devices are slightly lower priced.
ST Micro 8Kx8 DS1225AB equiv. M48Z58Y-70PC1
ST Micro 32Kx8 DS1230 (DS1235) equiv. M48Z35Y-70PC1
--Victor
--- In TekScopes@yahoogrou <mailto:TekScopes%40yahoogroups.com> ps.com, "John Miles" <jmiles@...> wrote: Is it practical to
Dremel the Dallas part open and replace its integral lithium cell with an
outboard cell?
-- john, KE5FX
Yahoo! Groups Links
|
Mr. Silva,
Its been a while. How is the 2465B going with FRAM ?
toggle quoted message
Show quoted text
--- In TekScopes@..., "Victor Silva" <daejon1@...> wrote:
I have found that the FRAM devices are not a viable option in the
243X/40. Sadly I must report that what looked like a very promising
alternative to the DALLAS RAM/Lithium cell combo has turned out to be
a dead end.
I have been testing for over one month now on a 2430A, 2440 and 2465B
and everything seemed fine. My last test was to actually determine
the read/write frequency to the device.
It turn out a 2430A writes to the battery-backed devices as often as
once every microsecond. Since the FRAM device as a maximum of 10^10
read/write cycles (before it loses its NV capability) a quick
calculation reveals that the 2430A scope will render the FRAM device
a volatile device in one to three months.
For now I can only recommend the DALLAS (or other vendors)
RAM/Lithium cell combo pack device for use in Tek scopes.
Sorry for getting everyone's hopes up for a more inexpensive
replacement for NVRAM.
--Victor Silva
|
| You could add extra logic and a counter to switch between fram chips and increase the mtbf time, or even better make your own NVRAM.
Oh, and if you keep the fram at 25?degrees?Celsius?you will probably get 10 times more write cycles.
|
--- On Sun, 3/17/13, bravovb wrote:
From: bravovb
Subject: [TekScopes] Re: Replacement to DS1230AB Lithium
backed NVRAM
To: TekScopes@...
Date: Sunday, March 17, 2013, 8:54 AM
?
Mr. Silva,
Its been a while. How is the 2465B going with FRAM ?
--- In TekScopes@..., "Victor Silva" wrote:
>
> I have found that the FRAM devices are not a viable option in the
> 243X/40. Sadly I must report that what looked like a very promising
> alternative to the DALLAS RAM/Lithium cell combo has turned out to be
> a dead end.
>
> I have been testing for over one month now on a 2430A, 2440 and 2465B
> and everything seemed fine. My last test was to actually determine
> the read/write frequency to the device.
>
> It turn out a 2430A writes to the battery-backed devices as often as
> once every microsecond. Since the FRAM device as a maximum of 10^10
> read/write cycles (before it loses its NV capability) a quick
> calculation reveals that the 2430A scope will render the FRAM device
> a volatile device in one to three months.
>
> For now I can only recommend the DALLAS (or other vendors)
> RAM/Lithium cell combo pack device for use in Tek scopes.
>
> Sorry for getting everyone's hopes up for a more inexpensive
> replacement for NVRAM.
>
> --Victor Silva
>
|
The solution I used for my 2440 which I have discussed here a couple of times was to use the SRAM and EEPROM based NVRAMs from Cypress which as far as I have been able to tell in this case, can be used as direct replacements for the Dallas/Maxim SRAM based NVRAMs. They are not really any less expensive though than new Dallas/Maxim NVRAMs. They only save the SRAM contents to the EEPROM when power is removed or if specifically asked which is not going to happen without a firmware change so continuous writes are not a problem. I also considered reverting my 2440 to the earlier design where an external lithium cell was used. On Sun, 17 Mar 2013 15:21:13 -0700 (PDT), Gala Dragos <gala_dragos@...> wrote: You could add extra logic and a counter to switch between fram chips and increase the mtbf time, or even better make your own NVRAM.
Oh, and if you keep the fram at 25?degrees?Celsius?you will probably get 10 times more write cycles.
--- On Sun, 3/17/13, bravovb <vbingei@...> wrote:
From: bravovb <vbingei@...>
Subject: [TekScopes] Re: Replacement to DS1230AB Lithium backed NVRAM
To: TekScopes@...
Date: Sunday, March 17, 2013, 8:54 AM
Mr. Silva,
Its been a while. How is the 2465B going with FRAM ?
--- In TekScopes@..., "Victor Silva" <daejon1@...> wrote:
I have found that the FRAM devices are not a viable option in the
243X/40. Sadly I must report that what looked like a very promising
alternative to the DALLAS RAM/Lithium cell combo has turned out to be
a dead end.
I have been testing for over one month now on a 2430A, 2440 and 2465B
and everything seemed fine. My last test was to actually determine
the read/write frequency to the device.
It turn out a 2430A writes to the battery-backed devices as often as
once every microsecond. Since the FRAM device as a maximum of 10^10
read/write cycles (before it loses its NV capability) a quick
calculation reveals that the 2430A scope will render the FRAM device
a volatile device in one to three months.
For now I can only recommend the DALLAS (or other vendors)
RAM/Lithium cell combo pack device for use in Tek scopes.
Sorry for getting everyone's hopes up for a more inexpensive
replacement for NVRAM.
--Victor Silva
|
On Sun, 17 Mar 2013, Gala Dragos wrote: I can not understand guys, WHY BOTHER? You can get DS1230 from Mouser for something like $15 (I purchased one a week ago to replace DS1225Y in my 2467B scope.) You will get a real thing that you can just swap in and forget for the next 10 years. And you can transfer the original chip content to the new one easily so you won't have to recalibrate. What are you trying to save here? A buck? Whopping two bucks? Is it worth a trouble and all that work involved? You could add extra logic and a counter to switch between fram chips and increase the mtbf time, or even better make your own NVRAM.
Oh, and if you keep the fram at 25?degrees?Celsius?you will probably get 10 times more write cycles.
--- On Sun, 3/17/13, bravovb <vbingei@...> wrote:
From: bravovb <vbingei@...>
Subject: [TekScopes] Re: Replacement to DS1230AB Lithium backed NVRAM
To: TekScopes@...
Date: Sunday, March 17, 2013, 8:54 AM
Mr. Silva,
Its been a while. How is the 2465B going with FRAM ?
--- In TekScopes@..., "Victor Silva" <daejon1@...> wrote:
I have found that the FRAM devices are not a viable option in the
243X/40. Sadly I must report that what looked like a very promising
alternative to the DALLAS RAM/Lithium cell combo has turned out to be
a dead end. I have been testing for over one month now on a 2430A, 2440 and 2465B
and everything seemed fine. My last test was to actually determine
the read/write frequency to the device. It turn out a 2430A writes to the battery-backed devices as often as
once every microsecond. Since the FRAM device as a maximum of 10^10
read/write cycles (before it loses its NV capability) a quick
calculation reveals that the 2430A scope will render the FRAM device
a volatile device in one to three months. For now I can only recommend the DALLAS (or other vendors)
RAM/Lithium cell combo pack device for use in Tek scopes. Sorry for getting everyone's hopes up for a more inexpensive
replacement for NVRAM. --Victor Silva --- * * KSI@home KOI8 Net < > The impossible we do immediately. * * Las Vegas NV, USA < > Miracles require 24-hour notice. * *
|
>>>>¡°I cannot understand guys, WHY BOTHER?¡±<<<< ? The key to this one is to understand that¡¡by claiming to save a couple of bucks we can easily justify the repair taking 3 to 5 times as long to implement than is should¡.. thus turning a 1 (maybe 2) beer repair (time wise) into a full six pack minimum. With the added possibility of another 6pack in consultation with an ¡°expert¡± ? Hopefully helpful Rob
(now hopefully I don¡¯t lose my man club card do to letting out some insight) ?
toggle quoted message
Show quoted text
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Sergey Kubushyn
Sent: Sunday, March 17, 2013 5:56 PM
To: TekScopes@...
Subject: Re: [TekScopes] Re: Replacement to DS1230AB Lithium backed NVRAM? ? On Sun, 17 Mar 2013, Gala Dragos wrote:
I can not understand guys, WHY BOTHER?
You can get DS1230 from Mouser for something like $15 (I purchased one a
week ago to replace DS1225Y in my 2467B scope.) You will get a real thing
that you can just swap in and forget for the next 10 years. And you can
transfer the original chip content to the new one easily so you won't have
to recalibrate.
What are you trying to save here? A buck? Whopping two bucks? Is it worth a
trouble and all that work involved?
> You could add extra logic and a counter to switch between fram chips and increase the mtbf time, or even better make your own NVRAM.
> Oh, and if you keep the fram at 25?degrees?Celsius?you will probably get 10 times more write cycles.
>
> --- On Sun, 3/17/13, bravovb <vbingei@...> wrote:
>
> From: bravovb <vbingei@...>
> Subject: [TekScopes] Re: Replacement to DS1230AB Lithium backed NVRAM
> To: TekScopes@...
> Date: Sunday, March 17, 2013, 8:54 AM
>
> Mr. Silva,
>
> Its been a while. How is the 2465B going with FRAM ?
>
> --- In TekScopes@..., "Victor Silva" <daejon1@...> wrote:
>
>> I have found that the FRAM devices are not a viable option in the
>> 243X/40. Sadly I must report that what looked like a very promising
>> alternative to the DALLAS RAM/Lithium cell combo has turned out to be
>> a dead end.
>
>> I have been testing for over one month now on a 2430A, 2440 and 2465B
>> and everything seemed fine. My last test was to actually determine
>> the read/write frequency to the device.
>
>> It turn out a 2430A writes to the battery-backed devices as often as
>> once every microsecond. Since the FRAM device as a maximum of 10^10
>> read/write cycles (before it loses its NV capability) a quick
>> calculation reveals that the 2430A scope will render the FRAM device
>> a volatile device in one to three months.
>
>> For now I can only recommend the DALLAS (or other vendors)
>> RAM/Lithium cell combo pack device for use in Tek scopes.
>
>> Sorry for getting everyone's hopes up for a more inexpensive
>> replacement for NVRAM.
>
>> --Victor Silva
---
*
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
*
|
Not all the Dallas Semiconductor NVRAM are available, some of them are obsolete or they are very expensive.
The DS1250Y costs between $58 and $62 if is in stock.
The DS1486 is not available from reliable sources.
Those 2 parts are used on most of the TDS6xx scopes :(
toggle quoted message
Show quoted text
--- In TekScopes@..., "Rob" <rgwood@...> wrote:
?€?I cannot understand guys, WHY BOTHER??€?<<<<
The key to this one is to understand that?€??€?by claiming to save a couple of bucks we can easily justify the repair taking 3 to 5 times as long to implement than is should?€?.. thus turning a 1 (maybe 2) beer repair (time wise) into a full six pack minimum. With the added possibility of another 6pack in consultation with an ?€?expert?€?
Hopefully helpful
Rob
(now hopefully I don?€?t lose my man club card do to letting out some insight)
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Sergey Kubushyn
Sent: Sunday, March 17, 2013 5:56 PM
To: TekScopes@...
Subject: Re: [TekScopes] Re: Replacement to DS1230AB Lithium backed NVRAM
On Sun, 17 Mar 2013, Gala Dragos wrote:
I can not understand guys, WHY BOTHER?
You can get DS1230 from Mouser for something like $15 (I purchased one a
week ago to replace DS1225Y in my 2467B scope.) You will get a real thing
that you can just swap in and forget for the next 10 years. And you can
transfer the original chip content to the new one easily so you won't have
to recalibrate.
What are you trying to save here? A buck? Whopping two bucks? Is it worth a
trouble and all that work involved?
You could add extra logic and a counter to switch between fram chips and increase the mtbf time, or even better make your own NVRAM.
Oh, and if you keep the fram at 25 degrees Celsius you will probably get 10 times more write cycles.
--- On Sun, 3/17/13, bravovb <vbingei@... <mailto:vbingei%40yahoo.com> > wrote:
From: bravovb <vbingei@... <mailto:vbingei%40yahoo.com> >
Subject: [TekScopes] Re: Replacement to DS1230AB Lithium backed NVRAM
To: TekScopes@... <mailto:TekScopes%40yahoogroups.com>
Date: Sunday, March 17, 2013, 8:54 AM
Mr. Silva,
Its been a while. How is the 2465B going with FRAM ?
--- In TekScopes@... <mailto:TekScopes%40yahoogroups.com> , "Victor Silva" <daejon1@> wrote:
I have found that the FRAM devices are not a viable option in the
243X/40. Sadly I must report that what looked like a very promising
alternative to the DALLAS RAM/Lithium cell combo has turned out to be
a dead end. I have been testing for over one month now on a 2430A, 2440 and 2465B
and everything seemed fine. My last test was to actually determine
the read/write frequency to the device. It turn out a 2430A writes to the battery-backed devices as often as
once every microsecond. Since the FRAM device as a maximum of 10^10
read/write cycles (before it loses its NV capability) a quick
calculation reveals that the 2430A scope will render the FRAM device
a volatile device in one to three months. For now I can only recommend the DALLAS (or other vendors)
RAM/Lithium cell combo pack device for use in Tek scopes. Sorry for getting everyone's hopes up for a more inexpensive
replacement for NVRAM. --Victor Silva ---
*
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
*
|
On Tue, 19 Mar 2013, lazystrings wrote: There are even more exotic devices that are not available and worth rebuilding from discrete chips. DS1250Y is 4MByte device so no wonder it is expensive. But it easily replaceable with a small board with several chips and lithium battery. DS1486 is exotic so it is also worth rebuilding. But people were not talking about those. They were trying to rebuild readily available $15 chips used in older scopes. That doesn't make sense. Not all the Dallas Semiconductor NVRAM are available, some of them are
obsolete or they are very expensive. The DS1250Y costs between $58 and
$62 if is in stock. The DS1486 is not available from reliable sources. Those 2 parts are used on most of the TDS6xx scopes :(
--- In TekScopes@..., "Rob" <rgwood@...> wrote:
?????I cannot understand guys, WHY BOTHER??????<<<<
The key to this one is to understand that??????????????by claiming to save a couple of bucks we can easily justify the repair taking 3 to 5 times as long to implement than is should???????.. thus turning a 1 (maybe 2) beer repair (time wise) into a full six pack minimum. With the added possibility of another 6pack in consultation with an ?????expert?????
Hopefully helpful
Rob
(now hopefully I don?????t lose my man club card do to letting out some insight)
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Sergey Kubushyn
Sent: Sunday, March 17, 2013 5:56 PM
To: TekScopes@...
Subject: Re: [TekScopes] Re: Replacement to DS1230AB Lithium backed NVRAM
On Sun, 17 Mar 2013, Gala Dragos wrote:
I can not understand guys, WHY BOTHER?
You can get DS1230 from Mouser for something like $15 (I purchased one a
week ago to replace DS1225Y in my 2467B scope.) You will get a real thing
that you can just swap in and forget for the next 10 years. And you can
transfer the original chip content to the new one easily so you won't have
to recalibrate.
What are you trying to save here? A buck? Whopping two bucks? Is it worth a
trouble and all that work involved?
You could add extra logic and a counter to switch between fram chips and increase the mtbf time, or even better make your own NVRAM.
Oh, and if you keep the fram at 25 degrees Celsius you will probably get 10 times more write cycles.
--- On Sun, 3/17/13, bravovb <vbingei@... <mailto:vbingei%40yahoo.com> > wrote:
From: bravovb <vbingei@... <mailto:vbingei%40yahoo.com> >
Subject: [TekScopes] Re: Replacement to DS1230AB Lithium backed NVRAM
To: TekScopes@... <mailto:TekScopes%40yahoogroups.com>
Date: Sunday, March 17, 2013, 8:54 AM
Mr. Silva,
Its been a while. How is the 2465B going with FRAM ?
--- In TekScopes@... <mailto:TekScopes%40yahoogroups.com> , "Victor Silva" <daejon1@> wrote:
I have found that the FRAM devices are not a viable option in the
243X/40. Sadly I must report that what looked like a very promising
alternative to the DALLAS RAM/Lithium cell combo has turned out to be
a dead end. I have been testing for over one month now on a 2430A, 2440 and 2465B
and everything seemed fine. My last test was to actually determine
the read/write frequency to the device. It turn out a 2430A writes to the battery-backed devices as often as
once every microsecond. Since the FRAM device as a maximum of 10^10
read/write cycles (before it loses its NV capability) a quick
calculation reveals that the 2430A scope will render the FRAM device
a volatile device in one to three months. For now I can only recommend the DALLAS (or other vendors)
RAM/Lithium cell combo pack device for use in Tek scopes. Sorry for getting everyone's hopes up for a more inexpensive
replacement for NVRAM. --Victor Silva ---
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