At its autumn full-scenario new product launch on September 25, Huawei officially released a new generation of top flagship earbuds – HUAWEI FreeBuds Pro 3, which is also the world’s first TWS earbuds to apply NearLink technology and bluetooth technology. It also brings many functional upgrades such as HD spatial audio 2.0, clear call 2.0, and smart dynamic noise cancellation 3.0. Through the super computing power support of the self-developed Kirin A2 chip, the sound quality, connection, call and noise cancellation experience are comprehensively improved.
We have previously teardown Huawei products including: Huawei FreeBuds SE 2, Huawei FreeBuds Pro 2+, Huawei FreeBuds Pro 2, Huawei FreeBuds 5, Huawei FreeBuds 4E, Huawei FreeBuds 4, Huawei Watch Ultimate, HUAWEI Watch Buds, HUAWEI Watch GT Cyber, HUAWEI Watch GT3, HUAWEI Band 7, HUAWEI Band B7 and HUAWEI Sound Joy. Let’s take a look at the detailed teardown report of HUAWEI FreeBuds Pro 3.
01/ HUAWEI FreeBuds Pro 3 Charging Case Teardown
Open the charging case and take out the internal charging bin.
The light guide column structure of the indicator light inside the casing.
The structure inside the bluetooth pairing function button.
There is a rubber ring seal on the edge of the function button, which also improves the feel of button feedback.
The front structure of the charging bin is equipped with a plastic integrated middle frame (gray) and functional FPC.
The structure on the back of the charging bin is equipped with a wireless charging receiving coil.
The motherboard is fixed with screws at the bottom of the charging bin.
Speakers for lookup function, set with sponge gasket seal.
The FPC is connected to the motherboard through the BTB connector.
The wireless charging receiving coil is welded to the main board, and the solder joints are fixed with glue.
The wireless charging coil is bent to match the appearance of the charging case.
Remove the wireless charging receiving coil and fix the coil on the magnetic shielding sticker.
Speaker back structure. The speakers are connected to the motherboard via elastic contacts.
Disassemble the FPC connector on the motherboard and separate the frame on the charging bin.
The structure of the fixed cable on the frame – the opening corresponds to the thermistor on the FPC, which is used to detect the internal battery temperature.
Thermistor on FPC.
The bottom structure of the charging bin has a Hall element at the end of the FPC.
The metal connector for charging earbuds is soldered directly to the motherboard.
Separate FPC from charging case. The circuit on the FPC side.
The circuit on the other side of the FPC.
Micro button for bluetooth pairing function control.
RGB LED indicator for feedback on bluetooth pairing and charging status.
The Hall element on the FPC is sealed with glue and is used to sense the magnetic field changes when the charging case is turned on/off, thereby notifying the charging case MCU and earbuds to pair or disconnect from the connected device.
The internal battery structure is fixed with glue. Lithium-ion polymer battery model: HB751834ENW-11, 510mAh/1.97Wh/3.87V, made in China.
The information on the internal battery core after tearing off the outer insulation protective film comes from ATL.
The battery is soldered to the wires, and the protection circuit is located on the motherboard.
The circuit and components on one side of the charging case motherboard are all coated with glue for protection, and the wireless SoC is protected by a shielding cover.
The circuitry on the other side of the motherboard.
The bluetooth antenna on the edge of the motherboard is used for wireless signal transmission.
Silk screen 4616 IC.
Silk screen YCQA T7CD IC.
Maxic MT5705 wireless charging receiving chip supports Qi protocol. It uses an embedded ARM Cortex M0 processor, 2KB SRAM, 8KB OTP, and fully complies with the latest WPC Qi specification of BPP (version 1.2.4). It can provide up to 5W output power, support output voltage of 5V and current of up to 1A, and AC to DC conversion efficiency of 95%.
The high efficiency of MT5705 ensures its very low temperature rise and heat generation, and its wide FOD setting range makes it easy to pass WPC’s BPP certification. MT5705 also has a complete over-voltage, over-current, and over-temperature protection mechanism, which is especially suitable for various low-power smart devices such as TWS charging bins.
Silk screen 1224 TVS tube for input overvoltage protection.
Silk screen NZDX9F IC.
Silk screen P14 MOS tube.
Silk screen N6S 7 IC.
Silk screen RZR GRP IC.
Renesas DA9168 battery charging management chip has built-in dual independent LDO and reverse boost functions. Supports the USB On-The-Go (USB-OTG) standard, has extremely low quiescent current consumption and a very compact footprint, making it ideal for a large number of space-conscious battery-powered consumer product applications.
Southchip SC8753 is an efficient direct charging chip specially designed for TWS charging bin. The device is paired with the South Core SC7289 linear charging chip (earphones) to achieve charging or bidirectional UART communication through a 2-contact connection.
SC8753 adopts Buck Boost topology, integrates MOSFET, has low quiescent current and light load PFM mode. It provides excellent power efficiency, current and voltage regulation whether the charging voltage is above, below or equal to the input voltage. It supports an input voltage range of 2.7V to 5.5V and an output voltage range of 3.0V to 5.2V. SC8753 supports CC/CV loop. During the trickle charging and CV charging stages, the charging parameters are controlled by the SC7289 in the headset. During the CC charging stage, the SC7289 is fully turned on, and the SC8753 controls the charging current in constant current mode and supports continuous charging current up to 750mA, with ultra-low heat dissipation and high charging safety. In communication mode, charging is suspended and the 2-wire power connection switches to the UART data connection. With two-way UART communication over the power line, the charging case and earbuds can exchange data and request fast charging.
The charging case has a built-in buck-boost charging circuit, and the output voltage can be adjusted according to the earbud battery voltage to achieve pass-through charging of earbuds. Improving the voltage conversion efficiency in the charging case also eliminates the loss of linear charging of the earbuds, avoids charging heat, and extends the battery life of the earbuds.
The another Southchip SC8753 buck-boost chip, and the two chips charge the two earbuds respectively.
After removing the shielding cover from the motherboard, the circuit below. Silk screen 2670F04UHMTB wireless SoC is used for wireless communication with mobile phones to implement search functions.
02/ HUAWEI FreeBuds Pro 3 Earbuds Teardown
Remove the earbud stem back cover. There is a cover plate inside the cavity, and LDS laser antenna is printed on a large area for wireless transmission.
Remove the plastic cover.
The bluetooth antenna corresponds to the connection point on the motherboard.
The internal structure of the cavity, the FPC is connected to the motherboard through the BTB connector.
Unhook the connector and take out the motherboard. The circuit on one side of the earbud motherboard.
The circuit on the other side of the earbud motherboard.
Silk screen 653510 PMIC.
Huawei self-developed Kirin A2 chip, SiP (System in Package) system-level packaging, and the silk screen model is still “Hi1132”. According to official reports, the signal transmission efficiency of the Kirin A2 chip has been increased by 4 times, achieving an 8M bluetooth physical transmission rate, thus bringing super-CD-level lossless transmission of audio signals. Equipped with Polar Code technology, the anti-interference capability is increased by 2 times, ensuring stable and lossless transmission. Adopting a dual DSP architecture, the computing power is increased by 50%, bringing more efficient signal processing capabilities, making spatial audio more immersive, noise cancellation more accurate, and calls purer.
Silk screen UF IC.
The MEMS microphone of Lasdiao S811 3216F9 is an external noise cancellation microphone, which is used for the noise cancellation function to pick up external environmental noise.
Silk screen mH 3aM IC.
AWINIC AW86862 pressure sensing IC has a size as small as 1.41mm × 1.41mm, which reduces the board area by 67% compared with the previous generation. It has pressure sensing signal acquisition, amplification and processing functions, and integrates an I²C communication module, a system control module, a power management module and an AFE module (including 2 analog input differential channels and multiplexers, 2-stage PGA, 11-bit offset calibration DAC, 14-bit ADC and intelligent press logic processing module).
ST LSM6DSV16BX 6-axis IMU and bone conduction two-in-one chip. The 6-axis IMU is used for spatial audio function; bone conduction is used for uplink call noise cancellation, and the software supports head tracking and VAD algorithms.
Silk screen GM KH 52 IC.
Metal dome for connecting bluetooth antenna.
Another metal dome connected to the bluetooth antenna.
The internal structure of the earbud stem cavity.
The FPC connects to the metal contacts at the end of the earbud stem for connecting to the charging case for charging.
The pressure sensor on the cavity wall supports pinch and slide control. According to 52audio, it uses NDT pressure-sensitive solution.
The acoustic structure of the external noise cancellation microphone is equipped with a sealed sponge pad and dust filter.
The call microphone has an acoustic structure and a physical anti-wind noise structure design to prevent direct blowing.
The front of call microphone acoustic structure.
The inner structure of the call microphone pickup hole on the casing is protected by a wire mesh.
Disassemble the earbud head cavity.
The magnets fixed on the cavity wall are used to adsorb and fix the charging case. Heterosexual design, better utilization of internal space.
The battery is fixed inside the front cavity through a bracket, and a large amount of glue is filled and sealed inside.
Disconnect the solder joints and remove the battery.
There is a steel shell button battery inside the earbud, with a QR code label affixed to one side.
The other side of the steel case button battery.
Product model number on the label on the side of the steel case button battery: HB110580ENW-11.
Battery rated capacity: 55.5mAh; charging limit voltage: 4.48V; nominal voltage: 3.89V.
Internal structure of the front cavity.
Take out the transparent stand.
Clean off the fixing sealant and take out the dynamic speaker. An 11mm super-magnetic woofer is used, which is responsible for the bass part and can extend down to 14Hz.
The back of the dynamic speaker.
After actual measurement, the size of the bass unit is about 11mm.
Take out the FPC inside the earbud. The circuit on the FPC side.
The circuit on the other side of the FPC.
The FPC board is protected by a shielding cover. After removing the shielding cover, the circuit below.
The bone conduction VPU with silk screen QR code is used to accurately identify bone conduction vibration sounds – improving the sound pickup effect and making the sound clearer during calls or videos.
WINSEMI WSDF2310 integrated lithium battery protection IC is a highly integrated solution for single-cell lithium-ion/lithium polymer rechargeable battery pack protection. WSDF2310 includes advanced power MOSFET, high-precision voltage detection circuit and delay circuit; it has overcharge, over-discharge, over-current, short-circuit and other protection functions required by the battery; it consumes very low power when working, and also support CTL shipping mode settings.
Southchip SC7289 linear charging IC with system power path management and I2C interface for portable applications with limited space. SC7289 supports Bypass mode, which can realize low-voltage direct charging on the headset. In transport mode, the SC7289 supports a low battery leakage current of 400nA, extending battery cycle life.
SC7289 adopts WCSP-12 1.55mm X 1.95mm ultra-small package and can be widely used in rechargeable battery packs with very small space constraints. SC7289 cooperates with the SC8753 buck-boost chip inside the charging case to support 10C direct charging and has good thermal performance. The charging efficiency can reach up to 94%, thus improving the overall battery life of the product.
SC7289 and SC8753 support load detection function, which can save the Hall switch for plug-in detection. Both SC8753 and SC7289 have built-in UART switches, eliminating the need for external load switches or MOS control. It also integrates charging case and headset communication functions.
Optical in-ear detection sensor is used to automatically pause playback when taken off and resume playback after wearing.
The MEMS microphone of Lasdiao S811 is used to pick up sound from inside the ear canal. Three microphones + bone conduction CPU unit provide accurate sound pickup.
The earbud micro-plate tweeter – According to the official introduction, it uses a Halbach magnet array, which has better transient performance and the treble can extend upward to 48kHz. Bass unit + tweeter unit, combined with advanced digital crossover technology and 1.5Mbps lossless transmission, provide real and good sound across the entire link.
On the back of the micro-planar tweeter, the model information G35 MA1 is screen-printed.
After actual measurement, the length of the micro-planar tweeter is approximately 4.42mm, the height is approximately 2.97mm, and the thickness is approximately 1.88mm.
All components of HUAWEI FreeBuds Pro 3 true wireless noise cancellation earphones.
HUAWEI FreeBuds Pro 3 continues the design style of the series, but has been further optimized. The charging case size has been reduced by 4.5% again, making it more compact and portable. The earbuds adopt a smooth and round high-gloss texture, are lighter in weight than the previous model, and have 4 pairs of silicone eartips of different sizes, providing a more comfortable wearing experience. The earbud stem pressure-sensitive buttons have also been upgraded with a groove design for more precise touch control.
The charging case has a built-in 510mAh lithium battery, and the battery cells are from ATL. Supports both wired and wireless ways to charge the battery. Wired charging uses the Renesas DA9168 battery charging management chip; wireless charging uses the Maxic MT5705 wireless charging receiving chip. Two Southchip SC8753 buck-boost converters are used to charge the two earbuds through. It is also equipped with speakers and a wireless SoC internally for wireless communication with mobile phones to implement search functions.
The earbud is equipped with an 11mm dynamic woofer + micro-planar tweeter – the low-frequency can extend down to 14Hz, and the treble can extend up to 48kHz. Built-in three MEMS microphones + bone conduction VPU units for precise sound pickup for noise cancellation and voice call functions. It uses an optical in-ear detection sensor to automatically pause playback when taking off the earbuds and resume playback after wearing them. Uses pressure sensing sensor and AWINIC AW86862 pressure sensing IC to achieve precise and convenient pressure sensing control.
The main control uses Huawei’s self-developed SiP packaged Kirin A2 chip, which improves transmission efficiency by 4 times, anti-interference capability by 2 times, and computing power by 50%, providing strong support for the operation of various functions of the earbuds. It also uses ST LSM6DSV16BX 6-axis IMU and bone conduction two-in-one chip for spatial audio and call noise cancellation functions. The earbud has a built-in 55.5mAh 3.89V high-voltage steel case button battery and use the WINSEMI WSDF2310 integrated lithium battery protection IC. Southchip SC7289 linear charging IC, combined with the SC8753 buck-boost chip in the charging case, achieves direct-through high-rate and ultra-high efficiency charging.