I have implemented ADC for STM8S1003, but looking for a way to reduce the noise on he signal.

There's no offset but the ADC varies 50 digital levels for each analog voltage input.


I'm reading a DC voltage from a wearable biosensor, the input ranges from 0-5v. with sampling frequency of 444 kHz. I'm mearing the Digital output.


What are the most efficient way to reduce such an error?