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A2B Car audio bus - microphone array testYou are here: Home > Solutions > Automotive
A2B Car audio bus - microphone array test
1、Overview
Audio is the core function of the smart cockpit, covering applications such as car audio, speech recognition, e-Call, noise cancellation and echo cancellation. Incorporate more advanced and feature-rich infotainment functions to satisfy consumers' user experience. However, the traditional analog parallel audio signal transmission method is difficult to achieve a balance between increased functions and lightweight vehicles (reduced weight and cost of cables).
ADI (Analog Devices Inc.) launched the A2B (Automotive Audio Bus) car audio bus through the optimization of the audio bus, which can provide excellent audio quality than the traditional analog audio bus, and can also greatly save the weight and cost of car audio wiring harness ( about 75% reduction).
2、Application of A2B
The A2B bus is used to connect audio devices in the vehicle, such as MIC, power amplifier (AMP), multimedia host (Head Unit) and T-BOX, etc. Transmit audio data (I2S/TDM), control signal (I2C), clock and power over a long distance through a low-cost unshielded twisted-pair cable UTP. The digital interface eliminates the need for peripheral DAC/ADC conversion, providing a simpler, more convenient solution for audio designs while improving fuel efficiency.
3、Advantages of A2B
50Mbps Data Rates
up to 32 independent upstream and downstream
Single master device, multiple slave devices (up to 10) line topology
The connection between nodes can reach 15m, and the length of the bus can reach 40m
44.1KHz and 48KHz sample rate, and up to 32-bit audio
4、A2B audio bus transceiver tester
U 923 is an analysis solution based on the A2B test of the current emerging audio bus. The deterministic nature of A2B technology makes it suitable for use in long-distance audio scenarios. Combined with software tools, it can efficiently test various A2B components, such as speakers, audio amplifiers, microphone arrays, sensors and drivers.
5、Mic array A2B audio bus test link
Taking three ADI 2427 and ADI 2426 chip as an example, the signal test link of 12 Mic in total:
A. Control the PM 6682 audio acquisition card through the Audioexpert software to output the analog signal and push the AM 581 artificial mouth to play the sound signal through the power amplifier PM 0083.
B. The microphone array (12Mic) collects the acoustic signal broadcast by AM 581, and the U 923 A2B audio bus transceiver tester transmits the signal collected by the microphone array (12Mic) to the audio analysis software Audioexpert for analysis through the UTP unshielded twisted pair.
Core components
U 923,A2B Automotive Audio Bus Transceiver Test Device
PM 6682,2in, 2out, balance & unbalance
PM 0083,4ch IEPE,3ch AMP, High end
AM 581,Artificial Mouth, Low Distortion