VRE102CA

[macaba]

I've found some VRE102CA in my parts collection.

Has anyone used these before? I'm looking to get an idea of the actual performance of these parts.

The datasheet performance looks competitive.

[Andreas]

Hello,

the question is: are they from Thaler or after aquisition by APEX?

I had 2 devices VRE3050AS shortly after aquistion by APEX.
Tempco was good near room temperature.
But Hysteresis and 1/f noise (0.1-10Hz) were not at all good. (9-10uVpp instead of 3 uVpp typical)
And current consumption was rather low compared to the datasheet spec. (perhpas that explains the high noise).

with best regards

Andreas

[macaba]

Interesting! They're Apex from around 10-12 years ago.

[Andreas]

Hello,

my measurement is from 2011.
So I would measure at least the 0.1-10Hz noise before I use them in a critical precision cirquit.

with best regards

Andreas

[macaba]

Thank you for the advice, I don’t have any metrology suitable for displaying small noise signals like that (just a basic scope) so will investigate building an amplifier.

[Andreas]

Hello,

Several amplifiers (* 10000; 0.1-10 Hz) are described here:

https://www.eevblog.com/forum/metrology/diy-low-frenquency-noise-meter/msg938456/#msg938456

Also my version starting from here:

https://www.eevblog.com/forum/metrology/diy-low-frenquency-noise-meter/msg1148584/#msg1148584

full schematic:

https://www.eevblog.com/forum/metrology/ultra-precision-reference-ltz1000/?action=dlattach;attach=191057

Some users have made complete layouts e.g. here:
https://www.eevblog.com/forum/metrology/diy-low-frenquency-noise-meter/msg1230192/#msg1230192

the only thing you need besides a basic scope and a suitable amplifiere is a large metal cookies box for shielding.

with best regards

Andreas

[macaba]

Thank you for the links. I am designing something based on the OPA2210 so it’s very useful to read those links as they confirm I was thinking in the right direction. Particularly useful to see the input cap can be an electrolytic rather than some exotic.

[macaba]

I built a LNA and have gained confidence in it's results from measuring various things so it was time to put a VRE102CA to the test, to solve the question of whether I have a good batch or not.

I took 30 captures from the scope, example:


The average peak-peak voltage over 30 captures is 3 uVpp which is a good sign, half the 'typical' specification on the datasheet.

I put the data through a NSD generation script I created:


No 1/f noise. It appears to be a 'good' one. The next step is to measure all the devices I have and see what the deviation between devices is.