[volt-nuts] MAX6350 ?

[Andreas Jahn]

> There are other new-ish Vref products and, more interesting, new
> technologies, such as Analog Devices "XFET" etc[1].  None of these
> Vref's are really spec'ed for metrology grade apps, their long-term
> specs are really just "burn-in" indications.
>
I have examined some Intersil FGA-Reference which is specified with 0.5mV @ 
5V. (0.01%)
The ISL21009BFB850 has a "switch off" hysteresis. When switching off for a 
(very) short time
the reference voltage starts with a about 200 uV lower voltage. It needs 
several days until the
previous voltage is reached again. According to Intersil all "low power" 
references have
a longer startup-time.

>
> I have filtered out 91 of 172k measurements, because they were more
> than 5 stddevs out, I have not tried to find out what caused them,
> probably people turning flouresent lights on and off.

Are these values in row or are they randomly distributed?

On my measurements with MAX6250 I had some strange "jumps" of about 7uV
for some minutes in one direction and back after the minutes when doing the 
temperature cycling.
The jumps could be repeated on the next temperature cycling. The temperature 
of the jumps was not
constant but near the temperature of the previous cycling.

Best regards

Andreas