[time-nuts] Re: +1/f of transistors

[Mike Monett]

Here is a different approach to the 1/f problem.

Marco Reps has an interesting article on low noise amplifiers:

Ultralow Noise Tester: 9V Battery vs. 7805 vs. LTZ1000
https://www.youtube.com/watch?v=XpbDMo8an5w

He uses the zero drift op amp ADA4523: $3.03 at Mouser and Digikey
The datasheet is at https://octopart.com/search?q=ADA4523-1BCPZ

It shows 4.2nV/root(Hz) from 0.1Hz to 1Khz. Cross-correlation could bring
this down by 20dB.

The results could be combined with a low-noise bipolar to extend the
frequency range as high as needed.

The ADA4523 was released in 2020, so it was not available in 2014 when
Gerhard ran his famous "Noise Measurements On Chemical Batteries".

MRM