ADC is a class of chips that can complete the function of converting analog signals to digital signals. (as you said, \"human voice conversion to digital signal\") There are many categories in it: pipeline (high-speed, high-precision), flash (ultra-high-speed, low-precision), sigma-delta (low power), SAR (high-precision), etc. The specific type of ADC to choose is completely determined by your needs; When choosing a chip, look at their data sheet, which will indicate parameters such as sampling rate and resolution, and then choose according to your needs. ADC is a unidirectional conversion of analog to digital. If you want to convert digital to analog, you have to use DAC chips. Some chips can be inserted into the breadboard, so you need to pay attention to whether their pins meet your needs when choosing chips.