VRE102CA - Page 1
Forum section: electronics / general

author: macaba
author_rank: Regular Contributor
timestamp: April 06, 2020, 02:30:13 pm
content: 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.

author: Andreas
author_rank: Super Contributor
timestamp: April 06, 2020, 02:45:56 pm
content: 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 regardsAndreas

author: macaba
author_rank: Regular Contributor
timestamp: April 06, 2020, 02:55:54 pm
content: Interesting! They're Apex from around 10-12 years ago.

author: Andreas
author_rank: Super Contributor
timestamp: April 06, 2020, 03:58:07 pm
content: 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 regardsAndreas

author: macaba
author_rank: Regular Contributor
timestamp: April 06, 2020, 06:37:45 pm
content: 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.

author: Andreas
author_rank: Super Contributor
timestamp: April 06, 2020, 07:15:33 pm
content: Hello,Several amplifiers (* 10000; 0.1-10 Hz) are described here:https://www.eevblog.com/forum/metrology/diy-low-frenquency-noise-meter/msg938456/#msg938456Also my version starting from here:https://www.eevblog.com/forum/metrology/diy-low-frenquency-noise-meter/msg1148584/#msg1148584full schematic:https://www.eevblog.com/forum/metrology/ultra-precision-reference-ltz1000/?action=dlattach;attach=191057Some users have made complete layouts e.g. here:https://www.eevblog.com/forum/metrology/diy-low-frenquency-noise-meter/msg1230192/#msg1230192the only thing you need besides a basic scope and a suitable amplifiere is a large metal cookies box for shielding.with best regardsAndreas

author: macaba
author_rank: Regular Contributor
timestamp: April 06, 2020, 07:58:54 pm
content: 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.

author: macaba
author_rank: Regular Contributor
timestamp: June 11, 2020, 11:02:17 pm
content: 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.