The ADAU1373 is a low-power integrated digital audio processor that supports stereo 48 kHz recording and playback. Stereo Audio Codecs (ADCs) and DACs support sample rates from 8 kHz to 48 kHz with digital volume control.

The device offers 8 single-ended, or 4 differential analog inputs with PGA, adjustable gain from -12 dB to +18 dB. And can be configured for microphone or line level signals.

Two digital stereo microphone inputs are supported, and a total of 4 digital microphones can be connected. In addition, three serial digital audio input/output ports are provided, and asynchronous sample rate converters (ASRCs) are provided to support different sample rates, making mobile phone application system design more flexible. The inputs can be mixed before the ADC (or configured to bypass the ADC), or selected. Two stereo DACs are also included, with mixing options for flexible internal signal routing.

Figure 1 ADAU1373 functional block diagram

Analog outputs include line output, headphone output, speaker output and receiver output. Also included are two single-ended stereo line level outputs that can be configured as two differential outputs. The headphone output is true stereo, eliminating the need for coupling capacitors, and has a high-efficiency Class-G, Class-G, (track switch) architecture. A high-efficiency stereo, filter-free, Class-D switching amplifier provides 1W of stereo speaker power. Differential receiver amplifiers can be used to connect separate receiver speakers. Two PLL blocks that can lock to inputs from 8 kHz to 27 MHz.

DSP allows system designers to compensate for the real-world limitations of microphones, speakers, amplifiers, and listening environments, resulting in significant improvements in audio quality through equalization, multiband compression, and limiting algorithms. The SigmaStudio graphical development tool for rapid development of custom signal flows, including, audio processing blocks such as filters, mixers, dynamics processors and amplifiers can also be used to program the ADAU1373.

Figure 1 ADAU1373 functional block diagram

ADAU1373 Key Features

• 1 stereo ADC and 2 stereo DAC, sampling rate from 8kHz~48kHz

• Low power consumption: 7 mW at 1.8 V for recording, 6MW for playback, 48 kHz

• 8 single-ended, or 4 differential inputs, PGA

• 2 microphone bias references with current sense

• 2 stereo digital microphone inputs

• Flexible analog input/output mixer

• 1 stereo differential, or 2 stereo single-ended line outputs

• True ground-centered stereo class-G headphone amplifier capable of 2 x 50 MW at 1.8 V, 10% THD, 16Ω

• Filterless stereo, Class D speaker amplifier capable of 2 x 880 MW at 3.6 V, 10% THD, 8Ω, differential headphone amplifier capable of driving 32Ω

• 2 PLLs support input clocks from 8 kHz to 27 MHz

• I2C control interface

• Digital audio processing

• 3 digital audio input and output ports with ASRC

• I2S, PCM, right-justified, left-justified modes

• 4.05mm×3.82mm, 81-ball, 0.4 mm pitch WLCSP package

• -40℃~+85℃ operating temperature range

ADAU1373 Application

•cell phone

•tablet

• eBooks

• Portable media player

ADAU1373 Evaluation Board

The ADAU1373 is a low-power audio codec that supports stereo recording and playback. It provides eight single-ended or four differential analog inputs and PGA gain adjustment. It supports two stereo digital microphone inputs, so a total of 4 digital microphones can be connected. In addition, it provides three serial digital audio input/output ports and ASRCs to support different sampling rates, making it flexible for system design.

Its analog outputs include line output, headphone output, speaker output and a receiver output. Features two stereo single-ended line level outputs that can be configured as two differential outputs. Its headphone output is stereo, true ground centered, with an efficient Class-G architecture. Its high-efficiency stereo filter-free Class-D switching amplifier provides approximately 1 W of stereo speaker power. Differential receiver amplifiers can be used to connect separate receivers, speakers.

Figure 3 ADAU1373 Evaluation Board Circuit Diagram

The ADAU1373 evaluation board includes the ADAU1373 complete application circuit. The board has a USBI connection to the SigmaStudio graphical development tool to run a PC host that can be used to program the ADAU1373.

The user guide includes a detailed description of the ADAU1373 evaluation board. It is recommended to read both the ADAU1373 data sheet and this user guide. Full details are included in the ADAU1373 data sheet, which provides more detailed specifications, internal block diagrams, and application guidelines for the codec IC.