Digital circuits sometimes need analog circuits, such as comparator shaping;

Digital circuits can sometimes directly realize the functions of analog circuits, such as using an inverter to connect feedback resistors to amplify large and small signals.

Analog circuit is the basic component of digital circuit,

Such as diodes and triodes, which can be used for digital signal processing in switching state;

Looking closely at the internal structure of digital circuits, they are all composed of analog circuit units.

There are connections and differences, and different situations should be treated differently.