i'm having a little trouble getting my external reference to work properly.
I'm using Arduino Nano and the LM4040 5V and connected it through a 1k resistor to Vcc. It's basically just this configuration, only with the 5V instead of 4.096V and 1k resistor instead of 904.
If you have it for 5V and you are feeding it with 5V, theoretically the current will be 0 uA and the LM4040 -5V is not working.
As it is not working, any measurement of values becomes invalid.
Try feeding it with some voltage like 5.3V or 5.4V.
If... OP wants to measure absolute voltages in that range, then an ADS1115 (with internal 1.xxvolt reference and 4.096 volt PGA) could be a much better choice.
Let's wait until we know what needs to be measured.
Headroom for the LM4040 could be as low as 4.65 (Nano on USB supply) - 4.096 = 0.55volt.
Feeding it with 5V might be the problem.
I need the reference to make the measurement of my battery voltage more precise and stable while using this voltage sensor:
But instead of getting a new LM4040 with a 4.096V output, I can just work with the 4,84V I'm getting, right?
This value should be stable and therefore should work.
Or are there any other risks I'm not considering?
No need to have an external reference for that.
The Nano has a stable internal voltage reference of about 1.1volt, which you can select with code.
All you do is divide battery voltage down to about 1volt with a two-resistor voltage divider,
and add this line to setup(). analogReference(INTERNAL);
More info here.
Tell us which battery if you need help with resistor values.