SA9227 USB audio controller
The dedicated USB audio controller manages the USB connection and I²S audio streams.
USB Audio Platform
USB Hi-Fi 192K Audio Interface
An open-hardware USB audio input and output platform combining a dedicated USB audio controller, stereo DAC, stereo ADC, MEMS microphone and analog audio output.
High-quality stereo output
An AK4430 stereo DAC converts the digital audio stream to left and right analog channels.
Stereo audio capture
The AK5720 ADC provides analog-to-digital conversion for recording and audio-input applications.
Integrated MEMS microphone
An SPU0414HR5H microphone is included for voice input and recording experiments.
Media controls
Dedicated Play, Volume Up and Volume Down keys provide direct host media control.
Configuration and clocking
An AT24C256 EEPROM stores configuration data, while a 12 MHz crystal provides the reference clock.
Power and protection
Separate 3.3V and 1.8V rails, filtering components and USB ESD protection support the mixed-signal audio design.
Open production files
The final project contains OrCAD schematics, Allegro PCB, BOM, Gerber, drill and mechanical DXF files.
Design verification
The final hifi_0714 PCB report records zero DRC errors and zero database errors.
Validation status
The 192 kHz design target is documented by the project files; measured audio performance, supported host modes and production test results still need a public validation report.
PCB Layout
Mixed-signal USB audio board