Bose QuietComfort Earbuds true wireless noise canceling earphones teardown

On September 23, Bose held the 2020 audio new product launch conference in China, and released a variety of new audio products such as Bose QuietComfort Earbuds, Bose Sport Earbuds, Bose smart audio glasses, Bose Sleepbuds II, Bose QuietComfort 35 II noise canceling headphones, etc., with a comprehensive product line upgrade.

Among the many new audio products, QuietComfort Earbuds, Bose’s first true wireless noise-cancelling headset, is the most interesting. This headset continues the family style in appearance design, is smaller, and newly adopts an advanced shark fin earmuff design to make wearing more comfortable and stable; charging case supports Qi standard wireless charging, charging case wired charging 15 minutes can provide 2 hours of battery life for the headset; a single use of the headset can last about 6 hours, and the charging case can last up to 18 hours; Bose QuietComfort Earbuds support IPX4 waterproof and sweat proof, use bluetooth 5.1 chip, built-in “Tencent XiaoWei” voice assistant , Also supports the voice assistant to wake up the phone.

The official announced that Bose QuietComfort Earbuds combines the noise reduction technology of over-ear headphones. The earphones have two internal and external microphones to synchronously detect environmental sounds and sounds in the ear canal, which can accurately generate opposite signals within milliseconds to cancel noise and achieve active noise reduction. Bose QuietComfort Earbuds supports 11 noise reduction levels to cope with different usage environments. You can also preset three noise reduction levels for the headphones through the “Bose Music” APP, which is convenient and quick to use. The headset supports two touch methods, long press and double tap, and has a transparent mode. Let’s take a look at the in-depth teardown of 52audio!

| 1. Bose QuietComfort Earbuds charging case teardown

After unpacking the box, we have a comprehensive understanding of the design of the Bose wireless noise cancelling earplugs. The size of the headset and charging case are relatively large, and the internal space should be relatively abundant. Next, we will enter the disassembly process. The first to be disassembled is the charging case, let’s take a look at the solutions adopted by its wired charging power management system and wireless charging power management system.

Pry open the charging cockpit and connect multiple physical buckles.

The small PCBA that charges the earphones is connected to the motherboard through the FPC.

Disconnect the FPC, you can see the two major structures inside the charging case. Both PCBAs are fixed on the shell with screws.

The PCBA display on the inside of the charging cockpit shows that the wire is connected to the Pogo Pin for charging the headset, and the solder joints are reinforced with blue glue.

The other side of PCBA.

Micro button for quick pairing of headphones.

TI DRV5032 low-power Hall sensor is used to detect charging case opening.

The silicone sleeve inside the button. Play a certain dust and waterproof role.

Some product information is printed on the inside of the charging cockpit shell. The shell material is PC+ABS, and the charging case model is BCP003.

Internal structure of charging case.

Thermistor probe that detects the temperature of the wireless charging receiving coil.

The light guide and light shield on the inner side of the battery indicator position.

Encoded information inside the body shell.

Charging case internal circuit.

The other side of the charging case internal circuit.

The PCBA where the Type-C charging interface is located.

On the other side of the PCBA, the Bose brand logo is printed.

There is a dustproof and waterproof rubber ring at the Type-C charging interface.

TI silk screen SN393 IC.

Silk screen K7K IC.

The fuse of silk screen KI.

The TVS of the silk screen LT9F.

charging case motherboard circuit. The upper part is roughly the wired charging power management system, and the lower part is roughly the wireless charging power management system.

Charging case The circuit on the other side of the motherboard. The solder joint of the FPC that detects the temperature of the wireless charging receiving coil is reinforced with blue glue.

ESD protection tube of silk screen K2. The five solder joints above are the solder joints between the PCBA where the Type-C charging interface is located and the main board connection wire.

Silk screen K7K IC. The three wires on the upper left connect the soft pack battery.

Two MOS tubes.

Silkscreen 3901 dABM09 IC.

The IC of the silk screen FKAE A9D.

TI TPS62743 synchronous rectification step-down converter, used for battery step-down to supply power for MCU and other chips.

Silk screen KL7 IC.

The IC of silk screen 951B7.

NXP QN9080 32-bit ARM Cortex-M4 bluetooth low energy microcontroller. QN908x is a high-performance bluetooth low energy SoC single-chip platform with 10mW peak power, suitable for bluetooth smart applications.

NXP QN9080 integrates bluetooth low energy (v5.0) compatible radio, link controller, Host protocol stack and multiple GATT profiles, thus providing a single-chip solution for bluetooth smart applications. The integrated 32-bit ARM Cortex-M4F MCU with on-chip flash memory and a variety of analog and digital peripherals can provide a more efficient data fusion engine. This feature makes it an excellent solution for computing applications that require a large number of sensor fusion.

Other system features of NXP QN908x include fully integrated DC-DC converter, LDO, low-power sleep timer, battery monitor, high-resolution ADC and GPIO. These features can reduce overall system cost and size. The power supply voltage range of QN908x is 1.62 V to 3.6V. It has very low working current and ultra-low power consumption sleep mode, which can extend battery life.

NXP QN908x functional block diagram.

Onboard snake-shaped bluetooth antenna.

Label information outside the soft pack battery.

The manufacturer of the soft pack battery is Zhuhai Guanyu Battery Co., Ltd., model 762936HV-1, rated voltage 3.8V, charging limit voltage 4.35V, and rated capacity 850mAh/3.23Wh.

Information on the cell, CA762936HV, 3.27Wh.

The battery protection board is displayed with a lithium battery protection IC and a thermistor used to detect the battery temperature to provide battery overvoltage, overdischarge and overcurrent protection. The solder joints of the wires are sealed with blue glue.

The other side of the battery protection board.

Screen printing 8FC 124 protection IC.

Silk screen X0KL IC.

Silk screen 4E MOS tube, two protection circuits are output in parallel to reduce loss.

There is a layer of double-sided tape on the wireless charging receiving coil, which is pasted on the inside of the shell.

A close-up of the wireless charging receiving coil. The transmitting coil of the wireless charger generates a certain current in the receiving coil based on a certain frequency of alternating current through the electromagnetic induction effect, thereby transferring the electrical energy from the transmitting end to the receiving end, and then powering the battery in the TWS charging case.

Resonant capacitor and filter capacitor for wireless charging and receiving.

Renesas IDT P9225R 5W wireless charging receiver IC. P9225-R is a high-efficiency wireless power receiver (Rx) that uses magnetic induction charging technology to convert the AC power signal from the resonator to a regulated DC output voltage of 4.5V to 5.5V. The integrated low RDSON synchronous rectifier and ultra-low drop linear (LDO) regulator provide high efficiency, making the product ideal for battery-powered applications. Comply with WPC-1.2.4 protocol and compatible with PMA SR1.

P9225-R includes the industry-leading 32-bit ARM® Cortex®-M0 microprocessor with a high level of programmability. P9225-R also has a programmable current limit and a patented overvoltage protection function, eliminating the need for other capacitors commonly used in receivers, and minimizing the number of external components and costs.

P9225-R and P9038-R transmitter (Tx) together are a complete wireless power system solution for power applications up to 5W. P9225-R is available in a 52-WLCSP package, and its rated temperature is 0°C to 85°C ambient operating temperature range.

Renesas IDT P9225R details.

TI TPS610997 synchronous boost IC, used to boost the built-in lithium battery to charge the headset.

Silk screen ZYAD A9G IC.

The IC of silk screen 72GD and silk screen YK.

Part of the circuit on the motherboard.

Part of the circuit on the motherboard.

Five LED indicators are used to display the battery level. Each indicator is separated by foam to reduce light leakage.

| 2. Bose QuietComfort Earbuds teardown

Let’s continue to disassemble the Bose QuietComfort Earbuds. Iconic shark fin eartips and larger body and brand logo.

The earphone is a bean-type ear design. The surface of the shell supports double-click and long-press gesture touch. The earphone supports IPX4 waterproof and sweat-proof.

Close-up of the shell surface, frosted texture, delicate touch.

The pickup hole of the headphone feed-forward microphone has a double-row hole design.

The sound pickup holes of the headset call microphone are also designed with double-row holes.

The charging contacts and pressure relief holes on the inside of the headset.

Pressure relief/tuning hole on the shell.

Another pressure relief/tuning hole on the shell.

The infrared distance sensor at the junction of the sound cavity and the sound hole opens the window.

Another infrared distance sensor opens the window at the mouthpiece, both of which are used for in-ear detection to improve the accuracy of recognition.

A fine dust-proof net at the sound hole.

Remove the “shark fin” silicone earmuffs.

The appearance of “shark fin” silicone earmuffs. The earwings part provides certain support and shares the pressure caused by some earphones on the auricle; the auricle part is designed to fit the curve of the human ear. The official recommendation No. 1 earmuff is suitable for the oriental ear ; The umbrella structure of the earphone sound hole fits the ear canal, improving the airtightness of the ear canal, reducing external noise, and improving the sound quality and noise reduction effect.

Size code for silicone eartips.

A close-up of the umbrella structure of the sound hole.

Bose Logo on the inside of the earmuffs.

Remove the outer cover of the earphone along the parting line to see the internal structure.

The internal layout of the left and right earphones is similar, and the IC is slightly different.

Let’s first disassemble the left earphone to see its internal structural design.

Inside the cover, on the left is the LDS antenna for signal transmission, and the larger area on the right is the FPC for touch sensing.

Disconnect the FPC socket and detach the outer cover of the earphone.

Connect the Pogo Pin of the LDS antenna.

Another FPC connection on the motherboard is reinforced with glue.

Disconnect the FPC, there is a PCBA below.

The FPC connects two microphones.

The wire of the button battery is soldered to the motherboard.

The two PCBAs are connected together by a flexible cable.

The main board circuit is connected with the FPC in the sound cavity through the connector.

Disconnect the FPC connector.

Take out the motherboard circuit.

The size comparison of the main circuit of the earphone and RMB coin.

One side of the motherboard circuit.

The other side of the motherboard circuit. The upper left and upper right of the PCBA on the right are the solder joints of the charging thimble.

Screen the Hall element of TA to detect whether the earphone is put in the charging compartment.

Three LED indicators.

Silk screen FA EHE IC.

The IC of the silk screen 9DS.

The IC of silk screen 651RF3M0.

An IC of TI.

Silk screen 9TA17 RW289 IC.

Silkscreen 71215 BCBZ noise reduction IC, from ADI, customized by Bose.

Silk screen 9BR IC.

Cypress PSoC 4000S series MCU for touch detection.

ST STM32L4A6VG ultra-low power 80 Mhz Arm Cortex-M4 MCU with FPU, with 1 MB Flash memory, USB OTG, LCD, AES-256 and DFSDM.

ST STM32L4A6VG introduction.

The IC of the silk screen 73H.

The main control chip of Bose QuietComfort Earbuds is Qualcomm QCC5127. Qualcomm QCC5100 series chips integrate digital active noise cancellation technology, quad-core processor architecture, built-in dual-core DSP audio subsystem, support the latest TWS+ technology, that is, dual-channel synchronous transmission technology, wireless latency is lower, and more valuable is that in the voice Compared with previous calls and music streaming, the power consumption can be reduced by up to 65%.

According to 52audio, products from brands such as BOSE, SONY, 1MORE, Edifier, and vivo have all adopted Qualcomm solutions.

Qualcomm QCC5127 details.

There are two ICs in the right earphone that are different from the left ear.

Silk screen O4UNP IC.

Silkscreen 157 T949 IC.

Continue to disassemble the left earphone, separate the button battery and the housing of the sound cavity.

The size comparison of button battery and RMB coin.

There is an insulating film outside the button cell.

The button battery supplier is from VARTA, model CP1654 A3, diameter 16mm, height 5.4mm, rated voltage 3.7V, rated capacity 0.4Wh.

According to 52audio, many world-renowned brands, including Apple, Samsung, Sony, BOSE, B&O, Amazon, etc., have adopted VARTA button batteries in large numbers.

The button battery is fixed on a transparent bracket, and the bracket also functions to isolate the circuit and the sound cavity.

The bent part of the bracket is the inverted hole of the earphone.

Disassemble the sound cavity of the earphone along the mold line at the mouthpiece.

The speaker unit is welded on the FPC.

Pressure relief hole inside the shell.

Take out the speaker unit.

The position of the infrared distance sensor at the mouthpiece.

The opening of the infrared distance sensor.

The back-feed microphone is at the mouthpiece.

A fine dust-proof net at the mouthpiece.

Take out the transparent bracket in the sound cavity.

One side of the transparent bracket holds the battery, and the other side is a bass inverter tube design.

Take out the FPC in the sound cavity.

The internal components of the headset.

The shell where the sound cavity and the mouthpiece are connected.

The infrared distance sensor on the shell opens the window.

The pressure relief hole and the inverted tube design inside the earphone shell.

Adsorb the magnet and charging contacts of the charging cockpit.

The call microphone and the feedforward microphone of the headset are on the same FPC, and they are close together. The Simai silk screen 214 SU6XQ.

Wool cone dynamic speaker.

T iron on the back of the speaker.

The size of the dynamic driver is approximately 9mm.

The FPC in the sound cavity is connected to the speaker unit, two infrared distance sensors and the feed-back microphone.

The other side of the FPC.

The infrared distance sensor on the shell.

The infrared distance sensor at the mouthpiece.

Laser carving TAB8C8 720 MEMS silicon microphone. It is mainly used to pick up the mixed sound in the ear canal and assist active noise reduction.

All components of Bose QuietComfort Earbuds.

| Summary

Bose QuietComfort Earbuds are Bose’s first true wireless bluetooth headsets that support active noise reduction. The headset continues the family-style design in terms of appearance and is smaller in size, but compared to the mainstream true wireless headsets currently on the market in terms of size and weight It is still not dominant, but the active noise reduction effect is indeed very good.

The charging case cover is a physical pop-up structure. The charging case has a large size and sufficient internal space. In terms of wired charging power management system, Type-C interface input power, NXP QN9080 bluetooth low energy MCU has a high integration level, responsible for battery charging management, charging case control, and can be connected to mobile phones for easy firmware upgrades, etc.; soft package The battery supplier is Zhuhai Guanyu battery with a capacity of 850mAh, which can provide longer battery life for the headset; in terms of wireless charging, the charging case adopts the Renesas Electronics IDT P9225R, which supports the Qi standard and has a maximum output of 5W.

The layout and structure of the Bose QuietComfort Earbuds headphones are also very clear. There is plenty of space. The motherboard and battery in the headset can be placed in parallel. The feedforward microphone and call microphone are located on the bottom plane of the headset and are connected to the motherboard through the FPC. There is a transparent bracket in the earphone, which not only plays the role of fixing the battery and isolating the sound cavity, but also designed a bass inverter to enhance the bass effect. What is more exaggerated is that the headset uses two infrared distance sensors to more accurately monitor the wearing status.

Bose QuietComfort Earbuds supports 11 levels of noise reduction and adopts a hybrid noise reduction scheme. The feed-forward microphone is located at the bottom of the headset and is close to the call microphone. The rear-feed microphone is located at the sound hole. The structural design does not seem to be special. It should be Bose has a greater advantage in noise reduction algorithms. The noise reduction DSP comes from ADI, and the bluetooth main control chip is Qualcomm QCC5127; the touch solution of the headset comes from Cypress, and the button battery comes from VARTA. The official advertised a single battery life of about 6 hours. More components customized by TI and other brands are used in the headset and charging case.

In addition, Bose QuietComfort Earbuds uses a new “shark fin” earmuffs. No. 1 earmuffs are adapted to the auricles of Orientals to improve wearing comfort and noise reduction. On the whole, Bose QuietComfort Earbuds use better materials, the internal circuit protection is in place, and the main active noise reduction function experience is excellent.

Source: 52audio

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