Getting Started with Smart Home Audio Design

alan000345

Getting Started with Smart Home Audio Design [Copy link]

 

Author: Zachary Kingsak and Avi Yashar of Texas Instruments[/ align]

[/ size]

Smart home technology has been growing rapidly in recent years. More and more households are adopting smart speakers such as Amazon Echo and Google Home. Companies that once only produced simple household devices are now There is a need for high-fidelity audio output. This audio output goes far beyond the usual beeps or a tune that announces that the laundry is done; this audio technology can make a refrigerator read out the grocery list aloud, or make a light The switch reminds people to turn off the lights before leaving the room. =14px]Adding advanced audio features can be daunting and can complicate an already tight engineering team's schedule. In this blog post, I'll explore the key issues associated with smart home audio design. Four major challenges and how to simplify the design process.

1.[/ b]It is difficult to define project requirements.

The project you're working on sounds simple: make this device talk. But with audio output comes many design choices and challenges, picking the right one from a sea of options that all look very similar at first glance. Amplifier is not an easy thing.

To simplify the process of selecting an amplifier, TI's interactive block diagrams provide component recommendations for specific smart home applications. For example, Figure 1 shows a smart speaker block diagram that highlights features that can meet multiple Smart home designs require audio subsystems and a host of speaker amplifiers. The audio reference designs on the same page come with schematics and supporting parts that can be used as project templates, increasing system-level knowledge and making component selection easier. [/ size]

[color=rgb (170, 102, 102)][img]https://e2echina.ti.com/resized-image/__size/1230x0/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-73/2.png[/img ]

[size= 14px]Figure 1: Smart speaker block diagram

The TI block diagram is a great first step to get started, but the choice of speaker amplifier will ultimately depend on your project requirements. Two of the most common smart home product requirements are high efficiency and concise and focused device profiles.

2.[/ b]Audio output and advanced features can reduce energy efficiency.

Adding extra features to smart home devices increases power consumption, and audio features can also lead to this result. As technology companies continue to strive to develop green environmental protection technologies and governments issue regulations on backup power With the advent of new audio systems, it is becoming increasingly important to optimize next generation products to reduce power consumption. Inefficient audio systems are one of the main culprits of wasted power and reduced user satisfaction, increasing electricity bills and draining batteries faster. Electrical energy and even heat the device. Audio amplifiers don’t always work They can do the above, but they must respond when the user wants feedback or notifications; think of a security camera or smart display in idle mode. On the other hand, when you are having a pool party, Bluetooth The speaker needs to play summer playlists efficiently so that its battery can last all day. )]To address smart home-centric applications, TI's latest speaker amplifiers have advanced built-in power management features. This proprietary hybrid modulation scheme minimizes standby current consumption in >12-V systems while also enabling the board to use an audio signal envelope tracking algorithm. The Class H boost setting can extend the battery life of battery-powered systems by up to 40%. Figure 2 illustrates how the algorithm-controlled multi-step boost is used, especially when audio is playing and the gain is low. Significant power savings on fixed 12V power rails. [img]https://e2echina.ti.Figure 2: Class H multi-step boost rail provides significant power savings for a fixed 12V power rail. 3. Physical limitations limit audio performance. Electronic devices have shrunk to extremely compact designs. The small form factors of home devices have never left room for audio functionality, making it difficult to add additional components such as amplifiers, digital signal processors (DSPs), boost converters and speakers without increasing the overall size. TI's audio team took these limitations into account and focused on creating amplifiers that integrate more features, reduce external components and optimize the space occupied by the audio subsystem.

At the heart of the smart home ecosystem is the smart speaker, where high-quality music and virtual assistant feedback are critical to high user satisfaction. Adding an audio DSP to produce high-quality output also increases cost and printed circuit board (PCB) size. TI offers audio amplifiers with integrated processing capabilities so users can tune the speakers to output the clearest virtual assistant response and the richest music experience. External echo cancellation algorithms can even use the pre-processed signal to help smart speakers more accurately distinguish between audio output and user voice commands.

The high switching frequency of Class D speaker amplifiers causes electromagnetic interference (EMI), which distorts the audio signal. This is usually suppressed by multiple large inductors. However, features such as Spread Spectrum and Phase Optimization suppress EMI without the need for external inductors, saving space and cost while producing ultra-low distortion audio output.

In general, the output power of a speaker is closely related to its size; if you want louder volume, you need a larger transducer, but you may not be able to use a transducer when designing a product with limited space. Video doorbells need to output the homeowner’s words loudly and clearly, even in noisy environments, while maintaining a small and slim form factor. Smart speakers that fit into these designs also output less power, making them more susceptible to damage from overheating and over-temperature. But thanks to TI speaker protection algorithms, smaller speakers can safely output higher volumes, achieving unprecedented sound quality.

As shown in Figure 3, TI’s speaker protection algorithm with speaker protection algorithm Smart amplifiers allow engineers to take full advantage of speaker capabilities and output higher average power without removing transducer integration from the design. In a smart home, situation-dependent volume changes mean that a visitor sitting in a car can easily hear the owner's voice even if a car is speeding by.

Picture 3: Speaker protection algorithms enable speakers to output twice the volume of traditional amplifiers without damaging components. Poor heat dissipation in small form factors also poses a problem for shrinking smart home products. Heat can damage internal components, create a bad user experience, or cause the device to catch fire if not properly handled. Designing with heat dissipation in mind means considering PCB layout and copper trace thickness, or deploying methods such as 102)] Features such as thermal foldback allow speaker amplifiers to dissipate less heat by dynamically adjusting the gain of the audio signal in the event of an overheat condition. Thermal management must be kept in mind from the beginning stages of designing a safe and reliable product.

4.Using advanced audio amplifier technology/ features requires deep expertise and can be difficult to implement.

[color=rgb(85, 85,Advanced features that solve many problems may sound good during the research phase, but they are of little value if they are difficult to implement, especially for first-time audio engineers. Building features from scratch or implementing them with external components is difficult, inefficient use of PCB space, and requires expertise in power electronics and signal processing. To simplify the design of next-generation products, TI has not only integrated a variety of features into its amplifiers, but also provided free software tools to help users easily control them. The PurePath Console 3 software suite simplifies the control of these devices by connecting to their evaluation modules (EVMs), allowing engineers to quickly use a modern, easy-to-use graphical user interface to quickly test and implement the features. 102)]Adjust audio output, calibrate settings, andcharacterize speakers. Step-by-step tuning and characterization wizards and extensive training resources flatten the learning curve associated with learning a new tool. The software is compatible with multiple TI audio evaluation modules (EVMs), allowing projects to incorporate new devices in the future without requiring changes to the software suite. Because power management, speaker protection and audio equalization are integrated into TI devices, they are easily configured through the PurePath Console software. They require little or no additional software development, which enables us to use these devices and software to create highly power-efficient, high-fidelity audio subsystems that improve user satisfaction while having a high degree of confidence that they can fit within the overall project schedule.

月下良缘

Thanks for sharing!