OPPO Enco Air2 earbuds and charging case have the characteristics of “beautiful appearance, exquisite design, and can provide 24 hours of long battery life in daily use, without getting tired for a long time.” As an upgraded product of OPPO Enco Air, I was impressed by its outstanding performance, but also curious about the internal structure of the product.
Next, we will teardown the OPPO Enco Air2 true wireless earbuds to see what combination of components and chips are used inside the product to bring us a good listening experience.
|1. OPPO Enco Air2 charging case teardown
After reading the exquisite appearance of the OPPO Enco Air2 true wireless earphones, let’s teardown the product and take a look at the internal structure of the product. First we start teardown from the charging case.
First, pry open the earphone cockpit along the parting line to separate the earphone cockpit and the charging case.
On the back of the earphone cockpit, it is fixed inside the earphone charging case through a buckle. There are also 2 magnets in the earphone cockpit for attracting the earphone.
Internal structure of charging case bottom case.
The inner structure of the charging case hinge, the use of the hinge structure can create a crisp opening and closing paragraph feeling.
Take out the earphone cockpit bracket.
There is a soft light structure in the place corresponding to the charging case LED light, which is used to make the light of the LED light softer.
The front of the earphone cockpit bracket is fixed with the battery, the integrated LED light and the FPC cable of the Hall element.
On the back of the earphone cockpit bracket, there is a metal sheet for charging the earphone.
The main board of the charging case, the important components are fixed with a large amount of glue to prevent loosening due to vibration.
The main board of the charging case is fixed on the headphone cockpit bracket by screws, and the main board of the charging case is coated with white glue to fix the main board.
The SS881A is one of the products of the SinhMicro POWR MCU SS881X series, with rich interface functions and flexible configuration modes. Different low power consumption options are supported, suitable for portable electronic products that require battery charging and intelligent control, and the charging voltage and current of the battery can be flexibly configured through software. At the same time, it also has built-in perfect protection functions, and the chip itself has passed the IEC62368 certification. Using SinhMicro’s MCU can bring a streamlined peripheral, excellent performance and flexible and convenient development to products such as TWS earphones.
The Type-C charging socket is fixed on the charging motherboard with black glue, and the laser engraves “EBAT1A”.
Regulator IC with silkscreen “905 S7”.
Screen-printed “24AF” TVS protection tube for input overvoltage protection.
Silkscreen “1HGBJ” IC.
The hall element with silk-screen “mH1n”, the magnetic field change when the charging case cover is opened/closed will be sensed by the hall element, and then the charging case MCU and earphones will be notified to pair or disconnect from the connected device.
The LED light used to indicate the working status of the charging case is surrounded by a black gasket to prevent light leakage.
The metal dome used to charge the earphone in the headset cockpit bracket.
Remove the charging case mainboard and the back of the charging case mainboard.
The front of the charging case motherboard. The FPC cable connecting the Hall element and the LED light is soldered on the motherboard.
The boost IC of ETA ETA1061, a high-efficiency synchronous rectification boost converter, has a true shutdown function inside, and does not require an external MOS tube control circuit to disconnect the load, which can achieve true shutdown and short circuit protection. The switching frequency of the ETA1061 is up to 1.4MHz, it can use small package inductors and ceramic capacitors, and the built-in synchronous rectifier can provide high efficiency. At the same time, the current mode compensation is integrated inside the chip, which can reduce the number of peripheral components.
The ETA1061 integrates short-circuit protection function, and provides SOT23 and DFN2*2 packages. There are 3.3V, 5V, and adjustable output voltage versions, which can be selected for different applications. Combined with the advantages of ultra-low quiescent current of 1μA, ETA1061 is ideal for device applications requiring low standby power consumption and small size, such as TWS headset charging case and other IoT devices.
According to 52audio, the audio products of Huawei, Xiaomi, Honor, OnePlus, realme, Edifier, 1MORE, Soundcore, UGREEN, RAPOO, Philips and many other brands have adopted the ETAsolutions power management solution.
OPPO Enco Air2 true wireless earphones battery information, the battery is from VDL, model 761832A, rated capacity 440mAh/1.07Wh, typical capacity 450mAh/1.71Wh, charging voltage 4.35V, nominal voltage 3.80V.
|2. OPPO Enco Air2 earphones teardown
After reading the teardown of the OPPO Enco Air2 charging case, let’s take a look at the teardown of the OPPO Enco Air2 earphopnes.
First, separate the front shell and the rear shell of the headphone head along the parting line.
The soft pack battery is arranged in the back cavity of the earphone head.
The dynamic unit of the OPPO Enco Air2 earbuds is fixed on the front shell of the headphone head using transparent glue and connected to the soft pack battery through a cable.
Detach the dynamic unit from the front of the headphone head.
The internal structure of the front shell of the headphone head, the large hole is the sound outlet hole of the speaker, the small hole is the pressure relief hole of the earphone, and the two openings are equipped with dustproof nets to prevent foreign objects from entering the earphone cavity.
The OPPO Enco Air2 earphones dynamic driver uses a composite titanium-plated diaphragm, which doubles the sound energy released by the previous generation.
After actual measurement, the dynamic driver size of OPPO Enco Air2 earphones is about 12.91mm.
Remove the earphone battery from the back cavity of the earphone head.
The internal structure of the back cavity of the headphone head is equipped with magnets for the adsorption of earphone and charging cockpit. In the back cavity of the headphone head, there is also a “C”-shaped bass duct structure designed with a bass port, which is used to provide a large sound cavity volume for the speaker and make the bass more rhythmic.
The noise-cancelling microphone pickup hole on the back cavity of the headphone head is provided with a fine dust-proof net.
The opening in the back cavity of the headphone head is used to pass the FPC cable connecting the motherboard and the battery.
Tear off the outer label of the battery, label information, model 105530, rated voltage 3.85V, rated capacity 0.103Wh.
Next, we open the back panel of the earphone handle and take a look at the earphone motherboard.
There is a capacitive touch patch in the back cover of the earphone handle, which is used to realize the touch function of the earphone. On the outer ring of the touch detection patch is the earphone’s bluetooth antenna, which is connected through the metal contacts on the motherboard.
The main board of the earphone handle is fixed on the earphone handle shell with a large amount of transparent glue.
The microphone pickup hole on the main board is equipped with a dust-proof net and a gasket to improve the sound-receiving performance while preventing dust.
The front of the headphone handle motherboard.
The back of the headphone handle motherboard.
The charging contacts soldered on the bottom of the earphone motherboard are used to charge the earphone.
BES BES2500 series bluetooth audio SoC is a new generation of BES bluetooth audio SoC, all support Bluetooth 5.2, and different suffixes have different configurations and functions. BES BES2500IUC/IU/IZ series, supports Bluetooth 5.2, ultra-low noise floor, 512K SRAM, 2M/4M FLASH, it is a cost-effective solution.
According to 52audio, the BES2500 series has been used in many products of Xiaomi, Samsung, OPPO, Honor and other brands. BES’ bluetooth audio solution has been widely adopted by Samsung, Xiaomi, OPPO, JBL, 1MORE, Honor, Baidu, OnePlus and other brands of true wireless earphones.
Connect the metal dome of the bluetooth antenna and the touch-sensing FPC.
A touch-sensing IC with silkscreen “31BP 7210F”.
TPS SY8602 is a single-cell lithium battery linear charging IC with constant current/voltage and integrated high voltage input. The IC can withstand input voltages up to 28V. To prevent excessive power consumption, the charging function will be turned off when the input voltage is higher than the 10V overvoltage protection threshold. Input voltage withstand capability up to 28V eliminates the need for input overvoltage protection circuitry for low voltage chargers.
The TPS SY8602 integrates an anti-reverse charging circuit inside and does not require an external isolation diode. The built-in thermal decay control can intelligently adjust the charging current to improve the reliability of the IC. SY8602 presets 4.2V/4.35V charging float voltage, and constant current charging current and charging cut-off current can be set by external resistors, especially suitable for the application requirements of portable products and other small lithium battery products. The SY8602 chip has passed the latest IEC62368-1 safety regulation certification, which provides a reliable guarantee for users to achieve high-quality product design.
According to the dismantling of I Love Audio Network, the TPS power management chip has been adopted by Xiaomi, OPPO, OnePlus, realme, Transsion, 1MORE, Baidu, Edifier, JBL, HARMAN, Lenovo, Monster and other brands.
The 26.000MHZ crystal oscillator provides the clock for the bluetooth chip.
Laser engraved “R19G 0D0B” MEMS microphone, used to pick up voice calls.
All components of OPPO Enco Air2 true wireless earphones.
In appearance, the OPPO Enco Air2 earbuds and charging case continue the classic design of OPPO Enco Air, with a smaller and lighter volume, and a new touch area indicator. In terms of functional configuration, it is equipped with a new unit, adopts the new Enco Live tuning, supports Bluetooth 5.2, AI call noise reduction, double-click remote control to take pictures, and has a 24-hour comprehensive battery life.
In the internal configuration of the charging case, the SinhMicro SS881A power microcontroller is used, which has rich interface functions and flexible configuration modes, supports different low-power options, and is suitable for portable electronic products that require battery charging and intelligent control. SS881A cooperates with ETA ETA1061’s high-efficiency synchronous rectification boost converter to provide powerful protection for earphones charging and discharging. The charging case battery comes from VDL, model 761832A, with a rated capacity of 440mAh/1.07Wh to provide earphones with an additional 18 hours of battery life.
At the same time, the charging case is also equipped with a Hall element to sense the opening and closing of the charging case, realizing the function of “open the box and pair devices automatically” of the earphones.
In the structure of OPPO Enco Air2 earbuds, the back cavity of the headphone is equipped with a “C”-shaped bass duct structure with a bass port design, which is used to provide a large sound cavity volume for the speaker and make the bass more rhythmic. The 12.91mm composite titanium-coated diaphragm dynamic driver provides a more surging listening experience.
The bluetooth SoC of earphones adopts BES BES2500 series bluetooth audio SoC, which is a new generation of BES bluetooth audio SoC. Both of them support Bluetooth 5.2. Different suffixes have different configurations and functions. BES BES2500IUC/IU/IZ series, supports Bluetooth 5.2, ultra-low noise floor, 512K SRAM, 2M/4M FLASH, it is a cost-effective solution. The benefits of using BES2500 series bluetooth audio SoCs are reflected in actual use, earphones have lower latency and a more cost-effective listening experience. The charging part is a linear charging IC using TPS SY8602, which integrates an anti-reverse charging circuit and does not require an external isolation diode. The built-in thermal decay control can intelligently adjust the charging current to improve the reliability of the IC.