Larger Capacitor Values in voltage divider circuit

[Luke.L]

https://devzone.nordicsemi.com/b/blog/posts/measuring-lithium-battery-voltage-with-nrf52

Following the calculations as so, I have worked out the necessary capacitor values(2.5nf) for my circuit, however such low value capacitors are fairly expensive for through hole mounts. Since this is a low volume POC circuit, i am looking for cheaper alternatives or maybe is it possible to do away with the capacitor altogether if I stay within the 40 TACQ [µs] acqusition chart of 800k ohm?

[ketiljo]

Just use a larger cap, 10 nF. The idea behind the external cap is to slowly charge this via the large series resistance, then dump the change quickly to Csample. If you use a larger cap, the only difference is that the time between the samples must be longer so that you have time to change the cap to the battery (divided) voltage.