On October 15th, OnePlus held a new product launch conference, and the new flagship mobile phone OnePlus 8T was unveiled as scheduled. At the press conference, OnePlus also released the new true wireless bluetooth earphones – OnePlus Buds Z, with a new in-ear design and the brand’s iconic CD texture on the touch area. Compared with the OnePlus Buds previously released by OnePlus, the OnePlus Buds Z earphones use nano-coating, support IP55 waterproof and sweat resistance, the earphones are lighter, and may be more suitable for sports wear as a whole. The price is also reduced to $49.99.
The OnePlus Buds Z earphones has a built-in 10mm dynamic unit, supports Dolby sound effects, has in-ear detection, call noise reduction, and fast charging. The functional experience is basically the same as that of OnePlus Buds. The new Charging case uses a capsule-style flip design, and the shell is smooth, not the BabySkin touch of the previous OnePlus Buds. A single battery life of the earphones is about 5 hours, and a 10-minute fast charge can provide 3 hours of battery life.
In addition, OnePlus has also collaborated with artist Steven Harrington to launch a customized version of OnePlus Buds Z, which incorporates graffiti design elements and has a more personalized appearance. The configuration should be no different from the regular version.
OnePlus currently sells audio products including neck-mounted bluetooth earphones OnePlus Bullets Z and wired earphones OnePlus Bullets. Let’s take a look at 52audio’s detailed disassembly of OnePlus Buds Z true wireless bluetooth earphoness!
01/ OnePlus Buds Z charging case teardown
After the previous unboxing, we have had a preliminary impression of the appearance of the OnePlus Buds Z earphones. Let’s take a look at its internal structure and power management system through disassembly.
Pry open the charging compartment and connect multiple physical buckles inside.
Inside the charging compartment, there is a structurally strengthened design, and two magnets are used to adsorb the lid.
Charging case internal structure display. The battery is fixed on a bracket, underneath is the motherboard circuit.
The hall element of AR0S1 silkscreen at the opening of the box cover. The magnetic field changes when the charging case cover is opened and closed will be sensed by the Hall element, and the charging case MCU and earphone will be notified to pair or disconnect with the connected device.
The white bracket also holds the Pogo Pin for charging the earphones, and two magnets are used to fix the earphones.
The battery is pasted on the bracket with double-sided tape.
Below the round foam are the fixing screws of the bracket and the motherboard.
Remove the screws, take out the white bracket, and display the internal structure of the charging case.
Displayed on one side of the white stand.
The white stand is displayed on the other side.
The PCBA is fixed on the shell by two screws.
The hood for the indicator light position inside the shell.
The internal structure of the charging case back button.
Internal circuit display of charging case.
The charging case internal circuit is displayed on the other side.
The FPC where the indicator light and the Hall element are located is connected to the motherboard through a connector.
FPC display where indicator light and Hall element are located.
Close-up of two LED indicators.
The other side of FPC is shown.
Charging case main circuit display.
On the other side of the charging case main circuit, copper vias are exposed at the power management IC for heat dissipation.
The Type-C charging interface comes from SHENZHEN KRCONN TECHNOLOGY CO., LTD.
The SY8801 chip specially designed by Siyuan Semiconductor for the TWS earphones charging compartment is designed to ensure safe and high reliability (support 28V input withstand voltage, built-in full-featured charging and discharging overvoltage, overcurrent, overtemperature, short circuit protection, etc. Function), also integrated I2C communication function and internal communication isolation function. Through the I2C interface, the MCU of the system can read and configure the internal functions of the power supply and the parameters of battery charging and discharging management, and easily realize such as NTC protection, segmented adjustment of battery current, TWS earphone storage, storage detection, and automatic power output. And other functions.
The internal communication isolation module integrated by SY8801 greatly optimizes the functional design of the smart TWS charging compartment, without complicated peripheral circuits, and the MCU can be realized by connecting and controlling the SY8801. Not only can it realize the function of charging the earphones, but also the data communication transmission can be carried out through the power source POGO PIN connected with the earphones, which includes functions such as uploading the power of the charging compartment, clearing the pairing of the earphones in the charging compartment, restoring factory settings, and upgrading the earphone software.
According to 52audio, Siyuan Semiconductor’s TWS earphones charging box power management chip has been adopted by many well-known brands such as OPPO, Xiaomi, Baidu, 233621, Transsion, Sabbat, Creative, and Sony Ericsson.
The ICM CM1112 series two-in-one protection chip is specially designed for the TWS earphones charging compartment battery. It has a built-in high-precision voltage detection circuit and a delay circuit. By detecting the battery voltage and current, the battery can be overcharged, overdischarged, overcurrent, etc. protection.
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 for TWS earphones charging compartments, smart watches and other wearable devices.
According to 52audio, there are already OnePlus OnePlus Buds true wireless earphoness, OPPO Enco W31 true wireless earphoness and Skullcandy Sesh true wireless bluetooth earphoness that have adopted a large number of ICM’s lithium battery protection ICs.
Various safety certification information on the battery insulation packaging.
For the battery information on the other side, the manufacturer is Chongqing VDL Electronics Co., Ltd., model: 782127, rated capascity: 450mAh/1.71Wh, nominal voltage: 3.8V, limited charging voltage: 4.5V.
According to 52audio, well-known brands such as Huawei, Xiaomi, Meizu, OPPO, etc. have adopted a large number of VDL Electronics batteries.
The information on the battery cell is consistent with the label.
The wires are connected to the positive and negative poles of the battery, and the battery protection IC is on the motherboard.
Cmsemicon CMS8S5880 single chip, used for charging case control. CMS8S5880 is an enhanced Flash MCU with 1T 8051 core, operating voltage 2.1V-4.5V, main frequency up to 24MHz, I/O up to 18, ADC, PWM, 2 UART, 1 SPI, 1 I2C, sleep state The lower quiescent current is less than 6uA, and it can work from -40°C to 105°C. Packages such as TSSOP20/QFN20 are available.
The IC of the silk screen 91ZP.
The IC of the silk screen 02AIN.
The IC of silkscreen NP6822.
The silver Pogo Pin for charging the earphone and the magnet for fixing the earphone.
The jog button is welded on the motherboard.
02/ OnePlus Buds Z earbuds teardown
Compared with the OnePlus Buds, the OnePlus Buds Z true wireless bluetooth earphones adopts an in-ear design, supports IP55 waterproof and sweat resistance, and retains the in-ear detection function, but the hardware configuration of the speaker unit and call noise reduction is also different. Let’s watch the disassembly!
OnePlus Buds Z is an in-ear design, which goes deeper into the ear canal when worn, and the shell of the sound hole is relatively slender, which can reduce discomfort; the free silicone earplugs can have a certain sound insulation effect.
earphone handle close-up. The touch area retains the unique CD texture design. The outer side of the earphone handle is a flat surface, and the opening above is the sound pickup hole of the call noise reduction microphone.
The sound pickup hole of the call microphone at the bottom of the earphone handle.
Pressure relief hole at the sound cavity.
Silver charging contacts on the inside of the shell.
Pressure relief/tuning hole near the sound hole.
The metal dust-proof net at the sound hole prevents foreign matter from entering.
Disassemble the earphone along the parting line of the sound cavity shell.
Close-up of the FPC connection in the sound cavity, fixed with fiber cloth.
The speaker unit is connected to the FPC in the sound cavity through a wire, and the FPC is connected to the battery FPC through a connector.
In the layout of the shell, the positive and negative electrodes of the battery are welded to the FPC.
Below the FPC is the battery of the earphones.
Solder the solder joints between the battery wires and the FPC.
The label information on the battery comes from Chongqing VDL Electronics Co., Ltd., model: 1063 PF3, rated voltage: 3.8V, rated capacity: 40mAh/0.152Wh.
The positive and negative leads of the battery are welded on the nickel sheet, which is located on the same side of the battery.
The size of the battery and the coin are compared.
Take out the battery and look at the structure inside the casing. It can be seen that there are perfect insulation protection measures around the battery and its bottom.
The battery is fixed on a white bracket.
Into the ear to detect the position of the FPC.
Close-up of the in-ear detection patch inside the cavity.
Remove the insulating plastic sheet separating the battery and the motherboard.
Use glue to reinforce the connection between FPC and motherboard.
The display on the FPC side connects the battery and the FPC in the sound cavity, and integrates in-ear detection.
Display on the other side of FPC.
The Hall element with silk-screen AL0 is used to more accurately determine whether the earphones is placed in the charging box.
The top structure of the earphone handle is displayed.
Dust net inside the pressure relief hole.
Disassemble the bottom of the earphone handle and take out the strip-shaped motherboard.
The foil used to detect touch control is connected with a metal shrapnel on the main board.
The structure inside the earphones is displayed.
Go back to the sound cavity and continue dismantling. Solder down the FPC, revealing the Pogo Pin for charging the earphones battery, and the magnet that attracts the charging cockpit in the middle.
The location of the other magnet.
The speaker unit is fixed with glue.
The size of the speaker unit is about 10mm, consistent with the publicity.
The size comparison of the strip-shaped motherboard and a dollar coin.
Circuit display on the motherboard side.
The circuit on the other side of the motherboard is displayed, and there is a QR code sticker on the main control chip.
A large amount of glue is used to seal the communication microphone at the bottom of the motherboard and the shell.
Remove the shell by heating, and there is a dust net inside.
Laser carving R027 AD1F’s MEMS silicon microphone is mainly used to pick up human voice and environmental sound during calls.
The MEMS silicon microphone of laser carving R033 AD1F is mainly used for environmental sound during calls. The main control chip compares two sets of voice information and uses related algorithms to extract human voices, thereby achieving the effect of noise reduction in calls.
On the other side of the motherboard is the protective cover and pickup hole of the microphone.
The main control chip of the OnePlus Buds Z true wireless bluetooth earphones is Bestechnic (BES) BES2300IU2. BES2300 has multiple versions and different configurations with different suffixes. Products using the BES2300IU2 model are basically at this price.
The BES2300 series is a fully integrated adaptive active noise reduction solution that supports bluetooth 5.0, IBRT low-frequency forwarding technology and dual-mode bluetooth 4.2. It also supports the third-generation FWS full wireless stereo technology, dual microphones, etc., using 28nm HKMG CMOS process, BGA package . BES2300 supports high-performance adaptive active noise reduction technology, which allows high-end active noise reduction earphones to use a fully integrated chip to achieve high sound quality and active noise reduction.
In addition, BES2300 also supports external heart rate sensors, acceleration sensors and other external sensor devices and eMMC flash memory, which can achieve the purpose of playing music on external storage devices. BES2300 can output sound to earphones and home audio, and can also record from an external microphone.
According to 52audio, a large number of true wireless earphoness from brands such as Huawei, Samsung, Xiaomi, OPPO, JBL, Wanmo, Honor, Baidu, OnePlus, and Transsion have adopted BES solutions.
A close-up of the ceramic bluetooth antenna for signal transmission.
Connect the metal shrapnel to the touch sensing area.
GOODiX’s GH610 in-ear detection and touch 2 in 1 solution. GOODiX GH61x series chips, using human capacitance detection patented technology, can assist true wireless earphoness to achieve automatic sleep, automatic wake-up, master-slave switching, automatic music start and stop functions, and improve user experience. At the same time, it supports touch, sliding volume adjustment and other rich Human-computer interaction function.
The GH61x series adopts dual-channel in-ear detection and the characteristic that the capacitance detection scheme only responds to electrodes, making it have a lower false recognition rate than traditional optical detection schemes. The chip integrates PMU and MCU, the algorithm runs independently on the chip, and reports events directly to the main control without the main control for data processing.
According to 52audio, TWS earphoness of OPPO, vivo, OnePlus, realme, Baidu and other brands also use GOODiX’s in-ear detection and touch 2-in-1 solution.
GOODiX GH61x block diagram.
The battery protection IC of the silk screen OKA4.
HYPWR HP4554 Lithium battery charging IC with high voltage input, simplified peripheral components, input protection voltage 6.8V, maximum withstand voltage 24V.
HYPWR HP4554 detailed information.
All parts disassembled.
The OnePlus Buds Z charging case adopts a new capsule-like appearance with a clamshell design. The smooth shell is not the BabySkin touch that was the main feature of OnePlus Buds; the earphone also adopts an in-ear design, and the touch area retains the iconic CD texture. The sound cavity is smaller and lighter in weight, supporting IP55 waterproof and sweat resistant.
In terms of internal circuits, the OnePlus Buds Z charging case uses Type-C interface input power, Type-C connector comes from SHENZHEN KRCONN TECHNOLOGY CO., LTD; Thinkplus Semiconductor SY8801 charging chamber chip, supports 28V input withstand voltage, built-in full-featured charging and discharging Over voltage, over current, over temperature, short circuit protection and other functions, SY8801 also integrates I2C communication function and internal communication isolation function. Through the I2C interface, Cmsemicon CMS8S5880MCU can read and configure the internal functions of the power supply and the parameters of battery charge and discharge management to achieve more control functions. The soft pack battery comes from Chongqing VDL Electronics Co., Ltd, with a capacity of 450mAh, and ICM CM1112 is responsible for overcharge, overdischarge, overcurrent protection, etc.
OnePlus Buds Z does not use a three-mic call noise reduction solution but a dual-mics solution. The internal structural design of the earphones is much simplified compared to OnePlus Buds. The bluetooth main control chip is the BES BES2300IU2, which is widely used in products of the same price. It also uses a patch ceramic bluetooth antenna to transmit data; the in-ear detection and touch 2 in 1 solution is still GOODiX GH610, and the earphones has a Hall element for more precision Detect the status of the earphone in/out of the charging box. The battery in the earphones is also from Chongqing Zijian, with a capacity of 40mAh. It is charged by HYPWR HP4554 and supports fast charging. The battery can provide 3 hours of battery life after 10 minutes of charging.
In addition, the OnePlus Buds Z speaker unit is a 10mm woofer, which is smaller than the 13.4mm dynamic unit built into the OnePlus Buds, but both support Dolby Atmos. From the OnePlus Buds Z, it can be seen that mobile phone manufacturers have a better balance between product differentiation, cost control and user core experience.