The SSM2603 is a low power, high quality stereo audio codec for portable digital audio applications with one set of stereo programmable gain amplifier (PGA) line inputs and one monaural microphone input. It features two 24-bit analog-todigital converter (ADC) channels and two 24-bit digital-toanalog (DAC) converter channels. The SSM2603 can operate as a master or a slave. It supports various master clock frequencies, including 12 MHz or 24 MHz for USB devices; standard 256 fS or 384 fS based rates, such as 12.288 MHz and 24.576 MHz; and many common audio sampling rates, such as 96 kHz, 88.2 kHz, 48 kHz, 44.1 kHz, 32 kHz, 24 kHz, 22.05 kHz, 16 kHz, 12 kHz, 11.025 kHz, and 8 kHz. The SSM2603 can operate at power supplies as low as 1.8 V for the analog circuitry and as low as 1.5 V for the digital circuitry. The maximum voltage supply is 3.6 V for all supplies. The SSM2603 software-programmable stereo output options provide the user with many application possibilities because the device can be used as a headphone driver or as a speaker driver. Its volume control functions provide a large range of gain control of the audio signal.