INNOSILICON™ Audio Codec IP consists of ADC channels, DAC channels, and bias circuit. The ADC channel is used to convert analog audio signals to digital signals. Each ADC channel contains input PGA, ALC, Sigma-Delta modulator, and digital filter. The DAC channel is used to convert digital audio signals to analog signals. Each DAC channel contains Sigma-Delta modulator, DCT, and power amplifier. The bias circuit generates voltage and current reference.