New TI Burr-Brown Audio Quad-Channel ADC Captures Voice at Four Time Larger Distances

November 5 2019, 00:50
No more yelling at smart speakers. Texas Instruments (TI) introduced a new audio analog-to-digital converter (ADC) capable of capturing clear audio up to four times farther away than competing devices. The new TI Burr-Brown TLV320ADC5140 audio ADC enables far-field voice capture and achieves a 120-dB dynamic range for clear, high-fidelity audio in smart home applications. The TLV320ADC5140 is the industry’s smallest quad-channel audio ADC with this level of performance.

Smart home systems face challenges with far-field audio capture. In today’s systems, a limited number of microphones and restricted signal processing capability make it difficult to capture and understand voice commands in loud environments. To meet this challenge, the TLV320ADC5140 enables engineers to improve audio capture from across rooms and boost recognition of soft-spoken commands in applications such as high-end smart speakers, sound bars, wireless speakers, high definition TVs, IP network cameras, teleconferencing systems and smart appliances. 

The ADC, which joins the portfolio of TI Burr-Brown premium audio devices, including high-performance Class-D amplifiers, data converters and operational amplifiers, can also help engineers save system design costs by reducing the number of microphones in the array.

The new TLV320ADC5140 device is part of a new family of three TI Burr-Brown audio ADCs that enable low-distortion audio recordings in loud environments, along with far-field, high-fidelity recordings in any environment. It supports simultaneous sampling of up to four analog channels or eight digital channels for the pulse density modulation (PDM) microphone input. The device supports line and microphone inputs, and allows for both single-ended and differential input configurations, integrating programable channel gain, digital volume control, a programmable microphone bias voltage, a phase-locked loop (PLL), a programmable high-pass filter (HPF), biquad filters, low-latency filter modes, and supporting sample rates up to 768 kHz. 

The TLV320ADC5140 supports time-division multiplexing (TDM), I2S, or left-justified (LJ) audio formats, and can be controlled with either the I2C or SPI interface. These integrated high-performance features, along with the ability to be powered from a single-supply of 3.3 V or 1.8 V, make the device an excellent    choice for space-constrained audio systems in far-field microphone recording applications.

Key features and benefits of the TLV320ADC5140 include the ability to capture clear audio in any environment in beamforming systems. The TLV320ADC5140 has a built-in 120-dB dynamic range enhancer (DRE). At a system level, the DRE scheme boosts low-volume audio signals while maintaining low-distortion recordings, even at close proximity to the speaker output. The DRE also improves far-field, high-fidelity recordings in all environments.

The TLV320ADC5140 is the first ADC that fully supports the latest high signal-to-noise-ratio microphones with greater than 106-dB dynamic range and allows for system flexibility with conversion of as many as four analog or eight digital microphones (or a combination thereof). The TLV320ADC5140 also includes programmable features such as gain and phase calibration to equalize microphone-array mismatches. Other features include a programmable gain amplifier, high-pass filters, channel mixing, and linear phase or ultra-low-latency decimation filters.

Using built-in features of the TLV320ADC5140, developers can offload digital signal processing tasks, allowing them to shrink their designs without sacrificing system reliability. Power consumption is only 9.5 mW per channel at 48 kHz.

The TLV320ADC5140 is available now in 4-mm-by-4-mm, 24-pin wafer quad flatpack no-lead (WQFN) packaging, and it is priced at US$2.99 in 1,000-unit quantities. The TLV320ADC5140 quad-channel 768-kHz TI Burr-Brown audio ADC evaluation module, ADC5140EVM-PDK, is available for $199 in limited quantities.
Watch the introductory video, “Enabling far-field voice capture in noisy environments with audio ADCs.”

Read also these application notes:
o Analog Microphone and ADC System in Far-field Application.
o Using the Dynamic Range Enhancer in TLV320ADC5140/6140.
o Multiple TLV320ADCx140 Devices with Shared TDM and I2C Bus.
For more information about TI’s broad selection of high-performance audio ADCs, visit:
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