OnePlus Buds Pro is OnePlus’ latest TWS earbuds in 2021, and it is also OnePlus‘s first true wireless earphones that supports noise reduction. OnePlus Buds Pro has two color schemes, each with completely different materials, and the craftsmanship is very delicate. At the same time, the earphone itself uses matte and metal texture, which collides with a strong design language.
In appearance, the charging case uses a square flip design, with the word “ONEPLUS” printed in the middle of the lid. The black version is mainly matte texture, and the white version uses piano paint. The earphone part adopts the high-gloss nano-NCVM coating process, as well as spraying and laser carving process polishing, so that it shows two different textures.
In terms of configuration, it has a built-in 11mm large unit, bluetooth 5.2 main control chip, supports LHDC audio codec, and supports personalized listening and Dolby panoramic sound effects. The newly-added intelligent active noise reduction function has a maximum noise reduction depth of 40dB, and supports transparent mode and three-microphone call noise reduction function. In other respects, it uses pressure-sensitive buttons, supports IP55 dustproof and waterproof, supports fast charging, wireless charging, and has a maximum battery life of 28 hours.
52audio also disassembled OnePlus Buds Z, OnePlus Buds true wireless earphones, OnePlus Bullets Wireless 2 and OnePlus Bullets Wireless Z Bass Edition neck-mounted bluetooth earphones, and OnePlus Bullets 2T Type-C earphones. Let’s take a look at the appearance design and internal structure configuration of this product.
|1. OnePlus Buds Pro Charging case teardown
After unpacking, we have learned about the overall appearance design and part of the structural location of this product. Let’s enter the disassembly part below to take a look at the internal design of this product.
Pry open the charging cockpit, there is an FPC cable connected to the motherboard inside the cockpit.
The flat cable is connected through the ZIF connector, which is easy to assemble. The ZIF connector comes from OCN, model: OK-F401-06125.
The FPC cable is connected to the charging pins on the left and right sides.
The bluetooth pairing button keycap is sealed and fixed by white glue.
The metal cover on the back of the charging contact is reinforced and fixed by a plastic column by heat fusion.
Charging case internal circuit.
The circuit board is coated with three anti-paint protection.
The Type-C charging interface small board is connected to the motherboard through a flat cable and a ZIF connector, and the flat cable is fixed on the motherboard with white glue. The ZIF connector comes from OCN, model: OK-F501-12325.
The LED indicator cable is connected to the motherboard through the ZIF connector. The ZIF connector is also from OCN, model: OK-F401-06125.
The wire of the wireless charging receiving coil is soldered to the main board, and the solder joints are coated with white glue to protect and fix.
The battery wires are soldered to the motherboard, and the solder joints are protected and fixed with white glue.
The main internal components of charging case.
The wireless charging receiving coil is fixed on the magnetic barrier sticker.
Wireless charging receiving coil.
Rechargeable lithium-ion battery model: 631940, rated capacity: 520mAh/1.976Wh, typical capacity: 525mAh/1.995Wh, charging limit voltage: 4.35V, nominal voltage: 3.80V, high-voltage battery, manufacturer: Chongqing VDL Electronics Co.,Ltd..
A sponge cushion is arranged in the battery frame to protect and fix the battery.
An indicator light cable is fixed on the side of the frame.
There are two LED indicators of different colors under the opening.
The silkscreen information on the battery cell is consistent with the external label information.
The battery protection circuit is arranged on the main board.
On the back of the Type-C power input interface small board, there is a ZIF connector on the small board, which is connected to the main board through a flat cable. The ZIF connector comes from OCN, model: OK-F501-12325.
An insulating rubber shield is provided on the other side of the power input interface.
The overvoltage protection IC of the silk screen 6M30P9, on the right is a TVS overvoltage protection tube.
Silkscreen MA’s IC.
charging case The front circuit of the motherboard.
The back of the motherboard exposes copper and immersion gold to help dissipate heat, and there are only two capacitors on the back.
ConvenientPower CPS3008 wireless power receiving and charging management chip, a single chip supports 5W wireless charging receiving, using WLCSP30 package.
Nuvoton MS51TC0AE microcontroller is an enhanced 8-bit 8051-core microcontroller with flash. The operating frequency is up to 24 MHz, and it supports a voltage range of 2.4 V to 5.5 V. It is used for charging case control.
Silkscreen S1 JY IC.
Prisemi P14C5N overvoltage and overcurrent protection IC is an overvoltage and overcurrent protection switch with adjustable OVLO threshold voltage and adjustable current limit threshold. At the same time, in order to deal with different adapter types, the adjustable over-current response time is specially customized, which is perfectly adapted to various charger types.
Willsemi WS4612 power distribution switch is a P-MOSFET high-side switch with ultra-low on-resistance. Integrated current limit function for power supply protection; also integrated reverse protection function to protect equipment and loads.
Silk-screen eCRF IC.
Silkscreen 8691W IC.
Silk screen AM CF IC.
Silkscreen CUYCOC’s IC.
The iCM Chuangxin Micro CM1112-WAE lithium battery protection IC of the silk screen 1112WAE.
The CM1112 series two-in-one protection chip is specially designed for the TWS headset charging compartment battery. It has a built-in high-precision voltage detection circuit and a delay circuit. By detecting the voltage and current of the battery, it can protect the battery from overcharge, overdischarge, and overcurrent. .
ICM CM1112 series products are ultra-small and ultra-thin DFN2.2*2.9*0.5mm package, which can achieve ultra-low 1.5uA static working power consumption and 10nA sleep power consumption, and integrate discrete NMOS with built-in ESD protection, which is very suitable for applications Lithium battery protection in TWS headset charging compartments, smart watches and other wearable devices.
According to 52audio, there are already products such as OnePlus Buds Z, OnePlus Buds true wireless earphones, OPPO Enco W31 true wireless earphones and Skullcandy Sesh Small Magic Bean true wireless bluetooth headphones that have adopted a large number of ICM lithium battery protection ICs.
|2. OnePlus Buds Pro earbuds teardown
Disassemble and enter the earphone part, first pry the earphone along the mold line.
The front and rear cavities inside the cavity are connected by a flat cable.
The front cavity is sealed with a cover plate to form an independent sound cavity structure.
Inside the back cavity are the main board and the battery unit, and the main board is covered by a sponge pad.
Multiple BTB connectors under the sponge pad are connected to the motherboard.
Pick up the BTB connector and coaxial cable one by one. The BTB connector comes from Yaqi Technology.
Take out the main components in the back cavity.
A capacitive in-ear detection sensor is fixed on the wall of the back cavity.
The in-ear sensor detects the flat cable and bluetooth coaxial cable.
Inside the back cavity is the double-sided tape to fix the battery, and under the double-sided tape is the feedback microphone.
The battery is isolated by high temperature insulation tape around it, and it is fixed on the main board with double-sided tape.
The silk-screen information 1056PF4-R-A3 on the battery FPC cable.
Lithium-ion soft-pack button battery model: 1056PF4, rated voltage 3.85V, rated capacity: 0.142Wh.
The front circuit of the motherboard, the middle three BTB connectors are from OCN, which are used to connect the front cavity speaker unit, the rear cavity in-ear detection unit and the earphone handle assembly. The models from top to bottom are OK-114GF012-35, OK-114GF016-35 and OK-114GF008-35.
According to 52audio, audio products under well-known brands such as Huawei, OPPO, JBL, Harman, Jabra, Amazom, Xiaomi, and Baidu have adopted OCN connectors.
The circuit on the back of the motherboard has multiple test points under the battery, and the edges are components such as step-down inductors and crystal oscillators.
Silkscreen DA’s iCM CM1123-DAC lithium battery protection IC.
CM1123-DAC has a built-in high-precision voltage detection circuit and delay circuit, which can protect the battery from overcharge, overdischarge, and overcurrent by detecting the voltage and current of the battery. It is suitable for the protection circuit of single-cell Li-ion/Li-polymer rechargeable batteries.
The IC of silk screen AH.
BES BES2500YP Ultra-low-power bluetooth audio SoC, supports dual-mode bluetooth 5.2, adaptive ANC active noise reduction function, and integrates high-fidelity audio DAC and ADC. By integrating the high-performance dual-core STAR-MC1 MCU subsystem and the ultra-low-power Sensor Hub subsystem, the power consumption is greatly reduced, and it also has powerful application processing capabilities. And through the BES patented IBRT technology to optimize the TWS application, improve the RF performance in the TWS system.
According to 52audio, the current BES2500 series main control chip has been adopted by many TWS headset products under brands such as OPPO and Honor. There are also true wireless headsets from brands such as Samsung, Xiaomi, OPPO, JBL, 1MORE, Baidu, OnePlus, Transsion, etc. that have adopted a large number of BES solutions.
TPS SY5500 bluetooth headset charging and communication solution. SY5500 is a chip specially designed for TWS earphones, providing a perfect solution for charging and isolating communication. The chip integrates linear charge management, discharge protection, single-wire two-way data communication (headphone compartment and headset) and I2C communication interface, which is convenient for users to realize headset charge and discharge management and protocol communication.
According to 52audio, the TPS power management chip has been adopted by many well-known brands such as BULL, Marshall, Soundcore, JBL , OPPO, Xiaomi, Baidu, 1More, 233621, Transsion, Sabbat, Creative, OnePlus, etc.
GOODiX GH6212, an all-in-one interactive sensor with functions such as pressure sensing, touch and wearing detection. It is used for in-ear detection and pressure sensing functions on this product.
The in-ear detection unit FPC is equipped with a feedforward noise reduction microphone at the end.
The FPC cable is fixed on the wall of the back cavity of the earphone by glue.
Laser carving R124 ADMF MEMS microphone, used for noise reduction function to pick up external environmental noise.
The feed-forward microphone inside the cavity has an opening and is covered by a fine dust-proof net.
Pry open the bottom cover of the earphone handle and take out the internal components. The internal components of the earphone handle are fixed on a transparent frame.
The earphone handle cover and the inside of the microphone windproof structure.
On the outside of the earphone handle cover and the microphone windproof structure, there is a magnet to help attract to the charging case.
A bluetooth antenna is attached to one side of the transparent frame.
The FPC cable on the other side is connected to the pickup microphone at the rear.
A pressure sensor is fixed on the other side, and there is a piece of black rubber that conducts pressure on the pressure sensor.
The front of the FPC circuit on the transparent plastic frame.
On the back of the FPC circuit on the transparent plastic frame, the bluetooth coaxial cable is soldered to the FPC.
The pressure sensor is New Degree PCB Sensor, model: PT061. It adopts a plug-in solution, is easy to integrate, and has the advantages of high sensitivity and wide response area. Support multiple control modes of single-click, double-click, triple-click, and long-press.
The milky white double-sided tape inside the transparent plastic frame is used to fix the pressure sensor.
The internal structure of the front cavity of the earphone, the charging contacts and the solder joints of the speaker are coated with a large amount of glue for protection.
Remove the glue and disconnect the cable to expose the metal contacts.
Remove the speaker, the pressure relief hole on the cavity wall, the inside is covered by a fine dust-proof net.
The loudspeaker is fixed inside the transparent cavity, and the inside is a layer of independent transparent cavity.
Take out the speaker unit, the sound cavity tuning hole in the cavity, and the inside is protected by a fine dust-proof net.
Inside the sound tube, a back-feed noise reduction microphone unit is provided for picking up the internal noise of the ear canal.
OnePlus Buds Pro true wireless noise reduction headphones dynamic driver front, dome metal evaporation.
The back of the dynamic driver.
After actual measurement, the size of the OnePlus Buds Pro speaker unit is about 11mm.
All components of OnePlus Buds Pro true wireless noise-canceling headphones.
OnePlus Buds Pro true wireless noise reduction headphones have a square design in the charging case, and the body is treated with a matte process, and the overall volume is very small. The earphone is a handle-shaped in-ear design, and the curve of the body is fit to the ear canal, which ensures the comfort and stability of wearing. The earphone handle design is more unique, using high-gloss nano-NCVM coating process, and after two processes of spraying and laser carving, showing a metal-like texture, with strong recognition.
In terms of internal circuit, the charging case uses Type-C interface input power; supports wireless charging function, the internal battery is charged by the ConvenientPower CPS3008 wireless power receiving chip, and the power management function is integrated. The built-in lithium battery has a capacity of 520mAh and comes from VDL. The iCM CM1112 series two-in-one protection chip provides overcharge, overdischarge, and overcurrent protection. Willsemi WS4612 power distribution switch, integrated current limit and reverse protection function, used to protect power supply and equipment. Nuvoton MS51TC0AE microcontroller, used for charging case control. And Prisemi P14C5N overvoltage and overcurrent protection IC, etc.
Inside the OnePlus Buds Pro earphones, the front cavity is sealed with a cover plate to form an independent sound cavity structure. In addition to the speakers inside the front cavity, there are charging contacts and a rear-feed noise reduction microphone, which are connected to the back cavity main board through a flat cable and a BTB connector. The back of the motherboard is fixed with a soft-pack button battery with tape, and a large-area capacitive in-ear detection sensor is installed on the wall of the back cavity. The inner cable of the earphone handle is fixed on the transparent frame and is also connected to the motherboard through the BTB. The cable is connected with a bluetooth antenna, a pressure sensor and a call microphone.
On the motherboard, the main control chip is BES BES2500YP ultra-low power bluetooth audio SoC, supports dual-mode bluetooth 5.2, adaptive ANC active noise reduction function, and integrates high-fidelity audio DAC and ADC. TPS SY5500 bluetooth headset charging and communication solution, used for headset charging and discharging management and protocol communication. GOODiX GH6212 all-in-one interactive sensor for in-ear detection and pressure-sensitive buttons. And iCM CM1123-DAC lithium battery protection, etc.