Transducer
Generates signal

Amplify and offset
Amplifies signal and adds DC offset to match ADC input range

Filter
Removes unwanted signal components, usually for anti-aliasing purposes

Multiplexer
Selects which input channel is connected to its output

Sample and hold
Samples its input signal and holds that voltage as a steady value at its output

ADC
Converts its analog input to a digital output

Input select

Sample

Start conversion

Conversion complete

Output result