According to the output mode of the voice chip is divided into two categories, one is PWM output mode, the other is DAC output mode, PWM output volume is not continuous adjustable, can not be connected to the ordinary power amplifier, most of the voice chip on the market is PWM output mode.
The other is the DAC amplified by the internal EQ, the voice chip sound is continuously adjustable, can be adjusted by digital control, and can be connected to an external power amplifier.
The playback function of the ordinary voice chip is essentially a DAC process, while the ADC process data is completed by the computer, including the sampling, compression, EQ and other processing of the speech signal.