ADAU1701JSTZ-RL

The ADAU1701JSTZ-RL is a highly integrated single-chip audio system from Analog Devices SigmaDSP product line, combining a powerful 28/56-bit digital audio processor with stereo ADCs, four-channel DACs, and comprehensive control interfaces all in a single 48-lead LQFP package. At the heart of the device is a 50 MIPS audio DSP core with 28-bit word length and 56-bit double-precision accumulator, enabling studio-quality audio signal processing with extremely low distortion and noise. The processing capabilities include equalization (parametric EQ, graphic EQ), crossovers, bass enhancement, multi-band dynamics processing (compression, limiting, expansion), delay compensation, speaker compensation, and stereo image enhancement – all configurable through the intuitive SigmaStudio graphical programming environment. The analog front end consists of two sigma-delta ADCs achieving 100 dB SNR and -83 dB THD+N, and four sigma-delta DACs delivering 104 dB SNR and -90 dB THD+N, providing a total analog-to-analog dynamic range of 98.5 dB. A standout feature is the self-boot capability, which allows the ADAU1701 to operate completely standalone without a microcontroller by loading its program from an external serial EEPROM at power-up. Parameters can be saved back to the EEPROM on power-down for persistent settings. For system integration, the device provides I2C and 4-wire SPI control interfaces, an auxiliary 4-input ADC for reading analog controls like volume pots, and multiple multipurpose GPIO pins that can be configured for digital inputs, outputs, serial data, or control functions. The integrated PLL generates the master clock from an external crystal, supporting 64x, 256x, 384x, and 512x sample rate multiplier ratios. The on-board 1.8V regulator allows operation from a single 3.3V supply, reducing external component count. The ADAU1701JSTZ-RL is supplied in tape and reel packaging for automated SMT assembly, with 500 pieces per reel.

The ADAU1701 operates as a complete digital audio processing system that can accept analog or digital audio input, process it with programmable DSP algorithms, and output the processed audio as analog or digital. At power-up, the device can boot in one of two modes: self-boot mode where it loads program code from an external serial EEPROM (selected by the SELFBOOT pin), or I2C/SPI control mode where an external microcontroller writes the program and parameters into the DSP memory. The DSP core uses a Harvard architecture with separate program and data memories. It executes audio processing algorithms on a sample-by-sample basis at the audio sampling rate, with each instruction executing in a single clock cycle. The 28-bit data path with 56-bit double-precision accumulator ensures that even with cascaded processing stages, the noise and distortion remain extremely low – comparable to high-end studio equipment. The safeload feature allows parameters to be updated during operation without causing clicks or pops in the audio, by writing to temporary registers that are then transferred to the active registers at a safe point in the audio cycle. The analog audio path uses sigma-delta conversion technology for both ADC and DAC. The ADC accepts current-mode inputs, allowing the full-scale voltage to be scaled with an external resistor. The DAC provides voltage outputs that can drive line-level loads directly. The PLL multiplies the external crystal frequency to generate the high-speed master clock required for the DSP core and sigma-delta converters. For analog control, the auxiliary ADC with its 4-input multiplexer can read potentiometers, rotary encoders, or other analog control signals, with the DSP handling the control logic and parameter mapping. GPIO pins provide additional flexibility for digital control inputs (pushbuttons, switches) and outputs (LED indicators, relay drivers, etc.).

• Multimedia speaker systems: 2.1, 5.1 channel home theater audio
• MP3 player docking stations and portable speaker systems
• Automotive head units and car audio signal processing
• Mini-component stereos and bookshelf speaker systems
• Digital TV and flat panel display audio enhancement
• Studio monitor speakers and nearfield monitors
• Active speaker crossovers and bi-amped/tri-amped speaker systems
• Musical instrument effects pedals and processors
• Aircraft and motor coach in-seat entertainment audio
• Soundbars and sound bases with virtual surround processing