March 30, 2019 by Sam Holland
It was quite a bold move when Apple released the iPhone 7 with no 3.5mm audio jack compatible with conventional earphones. But, fast-forward a few years, and wireless audio devices are becoming a mainstay in consumer electronics.
From the ubiquitous Apple 'Air Pods' to the competing 'Ear Buds' released by Samsung for the latest Galaxy S10 smartphone, there's a great product out there for every user.
Modern wireless earphones used with smartphones fall under the broader category of 'True Wireless Headsets', or simply TWS headsets. Unfortunately, most popular TWS audio systems have troublesome issues such as audio interference, device-to-device connection failures, and low signal strength to name a few. These pose technical issues to engineers from a design standpoint and significantly affect device usability on the consumer end.
Some leading component manufacturers have, however, risen to the task of producing components to tackle these issues. Below are some solutions engineers can incorporate in their projects:
Texas Instruments' OPA855 Decompensated Transimpedance Amplifiers offer wideband and low-input noise for wideband transimpedance and voltage amplifiers.
The OPA855 also provides very high transimpedance gain (>10K Ohms) when used as a Transimpedance Amplifier (TIA). Key features include 8GHz high-gain bandwidth product (GBWP) and ultra-low input voltage noise (0.98nV/√Hz). The OPA855 comes in a small-footprint 8-pin WSON package.
Benefits for true wireless audio systems: solves the problem of signal noise in TWS headsets. The OPA855 amplifiers offer excellent compatibility with low-profile, component-dense circuit boards.
The NXP® NXH2265UK NFMI is a single-chip solution with wireless audio and data communications using near-field magnetic induction (NFMI).
Key features include 2nd-Gen NFMI technology, a low power consumption, 596kb/s transmission rate, patent CoolFluxDSP® for high-speed audio processing, low latency ear-to-ear communications, and bi-directional audio streaming with sampling frequencies from 16 kHz to 48 kHz.
The NXP® NXH2265 is a power efficient solution that enables bi-directional audio streaming and unidirectional audio streaming at 1.2 mA and 1.95 mA respectively.
Benefits for true wireless audio systems: NFMI technology in the NXH2265 strengthens the device-to-device connection, preventing connection failures between TWS headsets and smart devices within specified ranges (typically up to 2 meters). Ultra-low power usage for bi-directional and unidirectional streaming prolongs the usage time of TWS devices.
Silicon Labs’ Si4840/Si4844 ICs are the world's first analogue-tuned, digital display CMOS AM/FM/SW ICs to implement a complete receiver function from antenna input to audio output.
The ICs are designed based on Silicon Labs' 'digital low intermediate frequency receiver' architecture to deliver enhanced radio frequency performance and ensure minimal interference.
Key features include Worldwide AM and FM band support at 64 to 109 MHz and 504 to 1750 MHz respectively, SW band support for the Si4844 variant at 2.3-28.5 MHz, automatic frequency control, bass treble support, Mono/Stereo audio indication, and compliance with RoHS and EN55020 standards.
Benefits for true wireless audio systems: the Si4840 / Si4844 Radio Receiver ICs patented RF infrastructure strengthens the connection between TWS headset and transmitting device to prevent device-device connection failures, significantly improves audio quality, and offers strong interference rejection and low power operation supplied via two AAA batteries (2.0 to 3.6 volts).
Qualcomm's QCA6390 is a 14-nanometer, system-on-chip (SoC) component with robust Wi-Fi and Bluetooth technology for enhanced audio connectivity and high-fidelity audio quality in wireless audio systems.
Key features include Bluetooth 5.1 and Wi-Fi 6 (802.11ax), next-gen WP3 security, 1024 QAM at 2.4 GHz and 5 GHz, and it also implements the revolutionary 8-stream sounding technology. The QCA6390 is indeed next-gen, through and through.
Benefits for true wireless audio systems: the QCA6390 SoC device puts an end to a number of issues that plague wireless audio connectivity including enhanced sound quality, blistering speeds of up to 1.8Gb/s (the highest tested audio throughput on any chipset in the industry), stable device-device connectivity with a combination of Bluetooth 5.1 and Wi-Fi 6 technology (50% more range than Wi-Fi 5), WP3 security, and low-power battery power consumption.
Photo courtesy of Unsplash.
Along with new and improved iterations of TWHs rolling out alongside flagship products from big brands, the wireless audio industry is set to expand further in the coming years.
The TWS audio solutions we have presented here are a few components which can aid engineers to design TWS audio systems with higher signal strength, improved reliability, functionality, and low power consumption.
