ADI 公司的SSM2603是低功耗高质量立体声音频CODEC,具有两个24位ADC和两个DAC通路,可工作在主或从模式,模拟工作电压1.8V-3.6V,数字核电压1.5V-3.6V,数字I/O电压1.8V-3.6V,3.3V和48kHz的DAC SNR为100dB(A加权),THD为-80dB而ADC的SNR为100dB(A加权),THD为-80dB,主要用在手机,MP3播放器,,手提游戏机,手持电子设备和教育玩具.本文介绍了SSM2603主要特性, 方框图, 典型应用电路图以及音频CODEC评估板EVAL-SSM2603主要特性,电路图,材料清单和PCB布局图.
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-to- digital converter (ADC) channels and two 24-bit digital-to- analog (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. Its volume control functions provide a large range of gain control of the audio signal. The SSM2603 is specified over the industrial temperature range of −40℃ to +85℃. It is available in a 28-lead, 5 mm × 5 mm lead frame chip scale package (LFCSP).

SSM2603主要特性:
Stereo, 24-bit analog-to-digital and digital-to-analog converters
DAC SNR: 100 dB (A-weighted), THD: −80 dB at 48 kHz, 3.3 V
ADC SNR: 90 dB (A-weighted), THD: −80 dB at 48 kHz, 3.3 V
Highly efficient headphone amplifier
Stereo line input and monaural microphone input
Low power
7 mW stereo playback (1.8 V/1.5 V supplies)
14 mW record and playback (1.8 V/1.5 V supplies)
Low supply voltages
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 over- sampling rate in USB mode
Audio sampling rates: 8 kHz, 11.025 kHz, 12 kHz, 16 kHz, 22.05 kHz, 24 kHz, 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, and 96 kHz
28-lead, 5 mm × 5 mm LFCSP (QFN) package

SSM2603应用:
Mobile phones
MP3 players
Portable gaming
Portable electronics
Educational toys

图1. SSM2603方框图

图2. SSM2603典型应用电路图

音频CODEC评估板EVAL-SSM2603
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. The board can operate as a master or slave and supports various clock frequencies. The SSM2603 software-programmable stereo output options provide many application possibilities because the device can be used as a headphone driver or as a speaker driver. Its volume control functions pro-vide a large range of gain control of the audio signal. Included in this data sheet is a detailed setup and user guide for the SSM2603 evaluation board hardware and software. Read the Evaluation Board Quick Setup section to ensure that proper communi-cation is established from the host PC to the SSM2603 evaluation board.
This data sheet describes how to configure and use the SSM2603 evaluation board. It is recommended that the SSM2603 evaluation board data sheet be read in conjunction with the SSM2603 data sheet, which provides more detailed information about the specifications, internal block diagrams, and application guid-ance for the codec IC.
The SSM2603 evaluation board carries a complete application circuit for the SSM2603. The board features a USB connection to a host PC. This serves as the power supply, digital audio data, and control/status data link, making it a plug-and-play USB audio device that can communicate with the software under the Microsoft® Windows® operating system. The board also has a general-purpose 2.54 mm pitch connector to connect to an external DSP/MCU for digital audio signals.

评估板EVAL-SSM2603主要特性:
USB connectivity to host PC
External connectivity to DSP/MCU for digital audio signals (available through general-purpose 2.54 mm pitch connector)
4 audio jacks: stereo line input, mono microphone input, stereo line output, and stereo headphone output
Multiple test points across the board for monitoring signals
Master/slave mode selectivity

图3.评估板EVAL-SSM2603外形图

图4.评估板EVAL-SSM2603电路图:SSM2603芯片

图5.评估板EVAL-SSM2603电路图:电源

图6.评估板EVAL-SSM2603电路图:数字缓冲器

图7.评估板EVAL-SSM2603电路图:模拟输出

图8.评估板EVAL-SSM2603电路图:模拟输入

图9.评估板EVAL-SSM2603电路图:USB MCU
评估板EVAL-SSM2603材料清单:




图10.评估板EVAL-SSM2603 PCB布局图:顶层

图11.评估板EVAL-SSM2603 PCB布局图:底层