Common digital audio AD and DA converter circuits in digital products

Shown are digital audio A/D and D/A converter circuits commonly found in digital products . The core of the circuit is an integrated circuit model PT8A3121. The microphone signal is input from the @ pin and is amplified and A/D converted in the integrated chip. The serial data signal is output from the @ pin. The microphone signal is also output from the @ pin and then sent to the @ pin. After amplification, it is output from the @ pin. After amplification, it drives the oscillator. The serial data signal from the digital circuit can also be input through the @ pin. The data from this pin can also be transmitted in both directions. After D/A conversion in the chip, it is output by the @ pin to drive the speaker.