Stereo Digital Audio CODEC Solution Using SSM2603

Stereo Digital Audio CODEC Solution Using SSM2603

Analog Devices' SSM2603 is a low-power, high-quality stereo digital audio CODEC for portable digital audio applications, with a set of stereo programmable gain amplifier (PGA) line inputs and a non-stereo microphone input. It has two 24-bit analog-to-digital converter (ADC) channels and two 24-bit digital-to-analog converter (DAC) channels. The SSM2603 can act as a host or a slave. It supports multiple master clock frequencies, including 12MHz or 24MHz for USB devices; standard 256fS or 384fS base rates, such as 12.288MHz and 24.576MHz; and many commonly used audio sampling rates, such as 96kHz, 88.2kHz, 48kHz, 44.1kHz, 32kHz, 24kHz, 22.05kHz, 16kHz, 12kHz, 11.025kHz, and 8kHz. The SSM2603 can operate at a minimum power supply of 1.8V in the case of analog circuits and at a power supply as low as 1.5V in the case of digital circuits. The SSM2603 software programmable stereo output option provides users with a variety of application possibilities. Its volume control function can control the gain of audio signals over a wide range. The industrial application temperature range of the SSM2603 is -40℃ to +85℃. It is available in a 28-pin, 5mm×5mm lead frame chip scale package (LFCSP).


Figure 1 SSM2603 functional block diagram

Figure 2 SSM2603 typical application circuit diagram

SSM2603 main features

• Stereo, 24-bit analog-to-digital and digital-to-analog converters

• DAC SNR: 100dB (A-weighted), THD: -80dB at 48kHz, 3.3V

• ADC SNR: 90dB (A-weighted), THD: -80dB at 48kHz, 3.3V

• High-efficiency headphone amplifier

• Stereo line input and monaural microphone input

• Low power

- 7mW stereo playback (1.8V/1.5V power supply)

- 14mW record and playback (1.8V/1.5V power supply)

• Low power supply

- Analog: 1.8 V to 3.6 V

- Digital core: 1.5 V to 3.6 V

- Digital I/O: 1.8 V to 3.6 V

• 256/384 oversampling rate in normal mode; 250/272 oversampling rate in USB mode

• Audio sampling rates: 8kHz, 11.025kHz, 12kHz, 16kHz, 22.05kHz, 24kHz, 32kHz, 44.1kHz, 48kHz, 88.2kHz, and 96kHz

• 28-lead, 5mm×5mm LFCSP (QFN) package

Figure 3 SSM2603 evaluation board top view

SSM2603 applications

• Cell phones

• MP3 players

• Portable game consoles

• Portable electronic devices

• Educational toys

SSM2603 evaluation board

The SSM2603 evaluation board carries a complete application circuit for the SSM2603 and connects to a PC host via USB. As power, digital audio data, and control/status data links, it becomes a plug-and-play audio device that can communicate through software under the Microsoft Windows operating system. The evaluation board uses a universal 2.54mm pin spacing connector to connect to an external DSP/MCU to obtain digital audio signals.

SSM2603 Evaluation Board Key Features

• Connects to host PC via USB

• Externally connects to DSP/MCU for digital audio signals (via universal 2.54mm pin, pitch connector)

• 4 audio jacks: stereo line-in, mono mic-in, stereo line-out, and stereo headphone-out

• Multiple test points on the board for monitoring signals

• Master/Slave mode selectable