Find some high stability RTC.

[WGNoise@gmail.com]

Hi,all
I am with a design which need very high frequency stabality RTC(real
time clock). 0.8ppm with temprature range from -40C --85C. I only
found the maxim's ds3221 with 3.5ppm from -40C --85C. Any suggestion?
thx

 

[martin griffith]

Hi,all
I am with a design which need very high frequency stabality RTC(real
time clock). 0.8ppm with temprature range from -40C --85C. I only
found the maxim's ds3221 with 3.5ppm from -40C --85C. Any suggestion?
thx

Not quite what you want, but
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=35006&item=7518769387&rd=1



martin

"Wales is a big welsh-shaped rain collection device"

 

[Pooh Bear]

Hi,all
I am with a design which need very high frequency stabality RTC(real
time clock). 0.8ppm with temprature range from -40C --85C. I only
found the maxim's ds3221 with 3.5ppm from -40C --85C. Any suggestion?
thx

Use an ovened crystal ? This was always the choice for frequency accuracy
of old. Does anyone still do them ?

Just looked. IQD certainly did in 1995 ( old data book ). Offered up to
0.25ppm freq stability.

Graham

 

[dalai lamah]

Un bel giorno WGNoise@gmail.com digitò:

I am with a design which need very high frequency stabality RTC(real
time clock). 0.8ppm with temprature range from -40C --85C. I only
found the maxim's ds3221 with 3.5ppm from -40C --85C. Any suggestion?

0.8 ppm in -40/+85 look *very* hard to achieve. You don't have to care
about the RTC, you need a very stable TCXO, or a OCXO.

 

[Rene Tschaggelar]

Hi,all
I am with a design which need very high frequency stabality RTC(real
time clock). 0.8ppm with temprature range from -40C --85C. I only
found the maxim's ds3221 with 3.5ppm from -40C --85C. Any suggestion?

A customized OCXO will do the job. Customized since the
temperature range is non standard. You sure could use a
normal OCXO running at +75 Degrees or so. But if it did
run colder, you'd possibly save a lot of power.

Rene

 

[René]

Use an ovened crystal ? This was always the choice for frequency accuracy
of old. Does anyone still do them ?

Just looked. IQD certainly did in 1995 ( old data book ). Offered up to
0.25ppm freq stability.

Graham

GPS derived? Internet time server? Radio controlled clock..
Even 50 Hz (60Hz?) controlled clocks should have good long term
stability.