My 3245A with a newly fitted ADR1399 (24hrs ago).
Recently re-capped.
3245A Vref circuit op-amps changed out for Chopper (yes I know....but I am experimenting!).
Red trace is workshop temperature (regulated).
PS. My workshop is quite noisy, LED lights, PC running, Server cabinet.......all within fairly close proximity.
No snubber fitted to ADR1399:
10NPLC, 5sec interval, 78mins total.
Max-Min across graph =
2.224uVSnubber fitted to ADR1399:
10NPLC, 5sec interval, 83mins total.
Max-Min across graph =
2.127uV![](https://www.ianjohnston.com/images/stories/IanJ/eevblog/3245_ADR1399NoSnubber.png)
![](https://www.ianjohnston.com/images/stories/IanJ/eevblog/3245_ADR1399WithSnubber.png)
Ian.