From "appearance" to "inner", comprehensively sort out the composition of TWS headphones
TWS earphones are a very popular product in the current consumer electronics market. Mobile phone brands, traditional audio manufacturers, and new TWS earphone brands are constantly launching new products. With the improvement of product performance and the continuous enrichment of functions, it has been recognized by more and more consumers, the user population is rapidly popularizing, and the market continues to expand.
The rapid development of TWS earphones has also driven the rapid growth of sales in related industry chains such as main control chips, power management ICs, wireless charging receiver chips, charging box batteries, earbud batteries, and sensors. To further enhance the market competitiveness, the related industry chain products are constantly being upgraded, which has promoted the improvement of the performance, function, and quality of TWS earphones, and formed a virtuous circle to promote the stable and healthy development of the TWS earphones market.
I Love Audio Network continues to pay attention to the TWS earphone market, shares the latest market information and product news for friends in real-time, and has successively released nearly 300 dismantling reports. And this time, I Love to make a complete list of TWS earphone parts for everyone based on the dismantling, and see how many parts are needed to build a TWS earphone~
1. Interpretation of TWS headset products
TWS earphones are True Wireless Stereo earphones, which completely abandon the way of wire connection on the outside, and mainly realize wireless transmission through Bluetooth technology. The main functions are listening to songs, talking, watching videos, games, etc., and it also has great potential to carry multimedia portals in the future.
In terms of product form, the most important feature of TWS earphones is that the two earphones exist independently, with neither the wire connected to the input mobile device nor the wire connection between the two earphones. It completely avoids the shackles of wires and can be worn on both ears, bringing a very flexible and convenient wearing experience.
In terms of appearance design, the mainstream products on the market currently adopt two forms "handle" and "bean type". Some products mainly in the sports market use a more stable ear-hook structure, as well as a bone conduction headset under You. Unique ear clip design.
In addition to the convenient wearing method, another reason for the rapid popularity of TWS earphones is the perfect cooperation between mobile phone accessories and mobile phones, as well as the rich functional experience compared to traditional earphones.
At the beginning of its birth, the TWS headset was criticized for its sound quality, battery life, delay, and other issues, but the convenient wearing experience and the lightweight and fashionable design without any wires gained the first batch of users. With the continuous advancement of related technologies, the performance of TWS headphones has gradually improved, and the user group has also begun to increase on a large scale.
In the past two years, the addition of many new functions such as active noise reduction, call noise reduction, spatial sound effects, wireless charging, game mode, etc. has further improved the experience of using TWS headphones, and the sales of TWS headphones have increased rapidly. At present, walking on the street and taking public transportation, TWS headphones have become the most popular products like mobile phones.
As an audio product, the most basic function of TWS headphones is still to meet the needs of users for music playback in leisure and entertainment, commuting, office, and other scenarios. With the rise of short video platforms, the application of TWS headsets in movie viewing is also growing rapidly.
The addition of the call noise reduction function makes the headset far away from the mouth, but it can also provide a clear call effect, plus a convenient call experience, making it a must-have product for many business people; and the active noise reduction function is further improved. The experience of using TWS headphones can still provide users with clear audio and video effects in noisy environments.
Judging from the current trend of functional application of TWS headsets, functions such as health monitoring and sports may also be equipped in the future. And it may also become an independent product with the development of technology, and audio playback can be performed without connecting to the audio device end. And become the access port of the Internet of Things, expanding rich application scenarios.
2. Interpretation of TWS earphone parts
From the product form, appearance design, and functional application of TWS earphones above, I talked about why TWS earphones have become more and more popular in recent years, and have become a must-have item for people. Let's take a look at what parts are needed to build a TWS headset from start to finish.
At present, the mainstream TWS earphone products on the market are mainly composed of a charging box and two left and right earphones. The components of the charging box other than the shell mainly include a power management chip and MCU, battery, power input interface, lithium battery protection IC, MOS, wireless charging receiving coil and chip (supporting wireless charging function), as well as carrying and connecting these components PCB boards, FPC cables, and wires, etc.
The main components of the headset include speakers, batteries, microphones, antennas, in-ear detection sensors, touch sensors, acceleration sensors, Bluetooth audio main control chip, noise reduction chip (supporting active noise reduction), lithium battery protection IC, program memory, etc. Because there are two earphones, all components need to be configured in pairs.
1. TWS earphone accessories
Charging Cable
Most of the current mainstream TWS headset charging cables have been updated to Type-C charging interfaces, and only a few old products still use the Micro USB interface. The Type-C charging cable is compatible with mobile devices such as Android phones, computers, and tablets. Only one set of charging devices is required to carry it out, which improves the convenience.
earplugs
Earplugs are standard accessories for in-ear headphones. The earplugs penetrate deep into the ear canal, forming a closed space in the ear canal, improving noise reduction performance, providing a more immersive listening experience, and improving wearing stability.
The current mainstream TWS earphones are mostly equipped with large, medium, and small sizes to meet the ear canals of different users. However, there are also many brand products equipped with earplugs of more sizes to further enhance the user's wearing experience.
2. TWS earphone charging box
mold
Mold is a very important part of the design process of TWS earphones. Unlike non-brand earphones, which can use relatively cheap male molds, brand earphones are mostly customized or bought out directly, thus creating a difference from other products. Improve competitiveness.
The development of earphone molds will vary in price according to different product requirements, ranging from basic 500,000 to 1 million and 2 million. The quality of the mold directly affects the performance stability of the product and the user experience.
Charging case cover shaft, magnet
The shaft structure of the charging box and the magnet are mainly used in the switch cover structure of the charging box in the TWS earphone. The two play a complementary role. With the Hall element, the automatic connection/disconnection function of the earphone is also realized.
Flagship-level mid-to-high-end products do relatively well in this regard and generally use a separate metal shaft structure to improve strength and service life. With the attraction/repulsion of magnets, the switch feels smooth and comfortable, not easy to close automatically, and the structure is very stable after closing the cover. Low-end products mostly use an integrated shaft structure, which is easy to automatically open and close the cover, and some products have a loose structure.
PCB printed circuit board
Printed circuit boards, also known as printed circuit boards, are the carriers of electrical connections for electronic components. TWS headphones are no exception. The main advantage of using circuit boards is to greatly reduce wiring and assembly errors, and improve the level of automation and production labor.
Battery
The batteries in the TWS earphone charging box are usually polymer soft-pack batteries, which are mainly divided into two types: square soft-pack batteries and cylindrical batteries, which are responsible for providing backup energy for the earphone battery and the internal circuit of the charging box. Under normal circumstances, only one battery is used in the charging box, and the capacity is 300-600mAh. But at present, some products have begun to use the two-battery solution, which can make better use of the internal space, increase the battery capacity, and thus improve the overall battery life.
charging interface
USB Type-C is the latest USB interface shape standard. The Type-C interface has the advantages of small size and can be used regardless of the front and back. It has strong versatility in the current consumer electronics market. Therefore, the new TWS earphone products have been updated to the Type-C interface, and only a few old products on sale have the Micro USB interface.
power management chip
The power management chip is installed in the TWS earphone compartment, which mainly plays two roles: one is responsible for charging the battery inside the charging compartment, and the other is responsible for the boost output of the battery inside the charging compartment to charge the earphones. In addition, it is also necessary to implement safety protection to prevent the built-in lithium battery from overcharging, over-discharge, overcurrent, short circuit, and other protection functions.
The power management chipset includes a charging chip, synchronous rectification boost converter, low dropout voltage regulator, load switch, input overvoltage, overcurrent protection chip, etc. There are three common modes of power management chips: the traditional solution of PMIC plus general-purpose MCU, the fully integrated solution of charger+boost+MCU single-chip, and the solution of single-chip charger+MCU and plug-in boost.
Charging compartment MCU
MCU is the (Microcontroller Unit) micro-control unit. The main functions of the TWS headset charging bin MCU are: charging management (charging + boost), the interaction between the bin and the headset (communication, Bluetooth interconnection), and the interaction between the bin and the mobile phone (accurate power The pop-up window shows, use Bluetooth for data transparent transmission), wireless charging.
Lithium battery protection chip
The lithium battery protection chip mainly realizes the protection of overcharge, over-discharge, and overcurrent of the battery by detecting the voltage and current of the battery to ensure safe and stable use.
Connector: BTB connector, metal dome, metal pogo pin
The connector is the device that connects the various components in the TWS headset. Through the connection of these connectors, the TWS headset can realize the connection operation between the various components. At present, the products used in TWS earphones mainly include BTB connectors, metal shrapnel, metal thimbles, etc. According to the different connected components, the most suitable products are used, which reduces labor and is easy to detect.
Wireless charging receiver coil (supports wireless charging products)
Wireless charging is a feature that many mid-to-high-end flagship products will carry, providing users with a more convenient experience. The wireless charging module is mainly composed of a wireless charging receiving coil and a receiving chip.
The transmitting coil of the wireless charger generates a certain current in the receiving coil through the electromagnetic induction effect based on a certain frequency of the alternating current, to transfer the electric energy from the transmitting end to the receiving end, with the wireless charging receiving chip, and then charging the battery in the TWS charging box powered by.
Wireless charging chip (supports wireless charging products)
The wireless charging chip is a power management chip for wireless input power. It integrates the charging unit and power management and protection functions. It is equipped with a wireless charging receiving coil to realize the wireless charging function for the TWS earphone charging box.
Hall element
Hall used in TWS earphones mainly plays the function of automatic connection and automatic disconnection of the switch cover, which is very convenient accessory support for TWS earphones. The Hall element senses the magnetic field changes when the lid of the charging box is opened and closed, and then notifies the charging box MCU and the headset to pair or disconnect from the connected device.
Indicator light
The indicator light is used for the TWS earphone charging box to feedback on the remaining power, charging status, and other functions, which are mainly distinguished by the number, different colors, and flickering frequency.
3. Headphones
Components such as molds, magnets, PCBs, connectors, LED indicators, charging ICs, and lithium battery protection ICs in the earphones have the same functions as those in the charging box, and will not be described below. Mainly to see what are the different components from the charging box~
mold
The TWS earphone mold has been mentioned above, so I won't go into details here. The difference from the charging box is that the earphones are divided into left and right ears, and due to the different wearing directions of the left and right ears, the left and right earmolds need to be developed separately, and most of them are symmetrical designs.
sound unit
In TWS earphones, the sounding unit plays the role of converting electrical signals into sound signals, mainly including moving coil and moving iron. These two sounding units will be combined or used independently. The number of units used will increase or decrease according to the sound quality requirements of the headset, such as different solutions such as single-action coil, single-action iron, and double-action iron. In addition, emerging solutions such as ring iron modules and moving porcelain speakers have also appeared in the market.
MEMS microphone
MEMS microphone is an acoustic sensor that uses MEMS technology to convert acoustic signals into electrical signals. Its function in TWS earphones is mainly for sound pickup. With noise reduction algorithms, it provides users with clear voice call effects and accurate AI. Voice control and active noise cancellation.
Battery
Both earphones of TWS earphones require built-in batteries. To adapt to different earphone forms, batteries are mainly divided into three types. There are three kinds of polymer soft pack batteries, button batteries, and needle batteries, which are suitable for different appearance designs, with a capacity of 30-60mAh, and are used for internal circuits, speakers, and other components.
Bluetooth antenna
The antenna is one of the important functional components of the TWS headset to achieve wireless connection. It mainly converts the high-frequency current energy output by the Bluetooth chip into electromagnetic waves for radiation, or converts space electromagnetic wave signals into high-frequency current energy and sends it to the receiver. The main Bluetooth antennas used in TWS headsets include printed antennas, FPC antennas, ceramic antennas, and LDS antennas.
In-ear detection sensor
In-ear detection in TWS earphones realizes the automatic pause when the earphone is removed, and the playback function is automatically resumed when the earphone is worn. It is also used to identify the single/binaural wearing mode to switch, and to switch between the headset and mobile phone handset during a call. The current TWS earphones are mainly realized by an optical infrared laser and capacitive induction.
capacitive touch sensor
At present, in the TWS earphone market, the operation control of earphones mainly consists of three methods: physical buttons, touch buttons, and pressure-sensitive buttons. Touch buttons are the most widely used solution at present, which can support multiple control modes of single-click, double-click, triple-click, long-press, and sliding. A Capacitive touch sensor is the component that provides support for it, with touch detection IC, to achieve precise control of various functions.
touch detection chip
The touch detection IC has been mentioned in the capacitive touch sensor. It is mainly used in the TWS headset to detect the state change of the sensor, report it to the main control chip, and then control the various functions by the main control. At present, many main control chips have integrated touch detection functions.
Pressure-sensitive sensor (supports pressure-sensitive button products)
The pressure sensor is an interactive way of the latest application on the TWS headset, which realizes the control of various functions by feeling the change of pressure. It has accuracy close to the physical button but does not need to open holes. Compared with the touch button, the control is more accurate, and it avoids the stethoscope effect caused by accidental touch and tapping.
Pressure-sensitive chip (supports pressure-sensitive key products)
Similar to the touch detection chip mentioned above, it is mainly used in TWS headset products that support pressure-sensitive buttons. It is used to detect the status of the pressure sensor and report to the main controller to control various functions.
bone conduction sensor
Bone conduction sensors are mainly used in some mid-to-high-end products. They mainly use vibration to determine whether it is the main human voice. They are used for noise reduction in calls. The bone vibration signal is combined with the microphone signal to improve the clarity of calls; it is used for voice interaction, Voice wake-up function to reduce false triggering problems that may be caused by external sounds, improve
Bone conduction sensors are mainly used in some mid-to-high-end products. They mainly use vibration to determine whether it is the main human voice. They are used for noise reduction in calls. The bone vibration signal is combined with the microphone signal to improve the clarity of calls; it is used for voice interaction, The voice wake-up function reduces false triggering problems that may be caused by external sounds and improves the accuracy of interaction.
Bluetooth Audio SoC
The Bluetooth audio main control chip is the most important component in the TWS headset. It is the basis for the TWS headset to realize functions such as wireless connection, audio processing, headset power management, and intelligent interaction. Its status is equivalent to the CPU processor in the mobile phone. The headset is mainly connected to the mobile phone and other playback devices through Bluetooth technology, and the audio signal sent by the terminal is transmitted to the two headsets at the same time through monitoring, forwarding, dual-channel connection, and other modes to form a stereo system.
Noise reduction chip
The noise reduction chip is mainly used in TWS earphone products that support the active noise reduction function. It is used to process the external noise signal collected by the microphone. After processing, the corresponding reverse sound wave is output, and then the speaker emits the reverse sound wave to cancel the noise. However, as the main control chip begins to integrate the active noise reduction function, the independent external noise reduction chip is used less and less.
storage
Since TWS headsets are currently mainly used with mobile devices such as mobile phones, computers, and tablets, there is no need for large-capacity storage inside. The memory in the TWS headset is mainly used to store Bluetooth pairing information and various preset functions. At present, most products are also integrated into the main control chip.
3. Summary
Different from mobile phone products, the exquisite and compact design of TWS earphones makes it impossible for ordinary consumers to disassemble them by themselves and learn independently what configurations are used inside the products and which functions are corresponding. Based on nearly 300 TWS earphone dismantling reports, this time I Love Audio.com has sorted it out in detail for everyone. Although there may be omissions, I hope it can help some friends who want to know more.
TWS headphones can become a very popular product in the current consumer market, and their internal configurations provide strong support for them. And due to the limitation of volume, the product needs a very high level of integration to realize the application of various functions. "Although the sparrow is small, it has all the internal organs" can very vividly describe the internal structure and configuration of the TWS headset.
With the rapid development of TWS earphones and the continuous advancement of technology, such as the power management chip in the charging box and the main control Bluetooth SoC in the earphone, the surrounding small devices are constantly being integrated, and the integration level is constantly improving, thus making the product quality more reliable. Control and stability are also better. On the other hand, the functions of TWS headphones are gradually enriched, and the highly integrated internal configuration also provides space for the application of new functions in the future.
From the end user's point of view, it means that the sound quality is improved, the delay is reduced, the battery life is longer, and the user experience is getting better and better. With the continuous enrichment of new functions such as active noise reduction and sports health monitoring, the application scenarios are constantly expanding, further improving the user experience.