The SMIC18_CODEC_01 specifies the design of a high-performance 16-bit stereo Audio CODEC for portable digital audio systems. The ADCs and DACs within the specification use sigma-delta technique. Input/output analog signals of the SMIC18_CODEC_01 are single-ended, including stereo input and stereo output. Mono microphone input is also supported with an internal microphone bias circuit. The internal stereo headphone amplifier is capable of driving 16Ω load. Low power consumption and flexible power management allow selective shutdown of codec functions, thus extending battery life in portable applications.