In terms of functional configuration, OPPO Enco Free 3 is equipped with OPPO’s first bamboo fiber diaphragm speaker unit, which greatly improves the high-frequency delicate of hearing sense and brings pure timbre. And a new customized natural bamboo rhyme tuning style, presenting a real, clear and pure natural hearing sense . Support Golden Hearing 2.0, customize listening compensation scheme, and realize personalized high-quality audio experience. OPPO Alive Audio spatial sound effect function, providing 360° surround sound effect. The earbud chip operates independently and is not limited to the use of bluetooth devices.
The bluetooth chip has been upgraded to Bluetooth V5.3, which provides faster and more stable wireless transmission, supports LDAC codec, and has obtained Hi-Res wireless audio certification. In terms of noise cancellation, it supports multi-scenario smart noise cancellation, ANC smart recognizes noise cancellation scenes and noise characteristics, matches the best noise cancellation effect, and has obtained TÜV Rheinland’s high-performance noise cancellation certification. Supports DNN call noise cancellation and AI smart wind noise algorithm to meet the needs of voice calls and windy scenes. In other aspects, it also supports low-latency game mode and dual-device connection, which can provide a single 7-hour battery life and a comprehensive 30-hour battery life.
We have teardown OPPO products before: OPPO Enco Air 3, OPPO Enco Air2 Pro, OPPO Enco Free 2, OPPO ENCO X2, OPPO Enco X, OPPO Enco R, OPPO ENCO Air 2i, OPPO Enco Air 2, OPPO Watch SE. Let’s take a look at the detailed teardown report of this product.
01/ OPPO Enco Free3 charging case teardown
Disassemble the charging case and take out the internal charging cockpit.
The bottom structure of the charging cockpit, the main board is fixed by screws.
The side structure of the charging cockpit is divided into upper and lower layers. The battery is fixed inside the cockpit and is wrapped in sponge to provide good protection.
The structure on the other side of the charging cockpit is connected to the Hall element through the FPC.
After separating the upper and lower cavities of the cockpit, the bottom structure of the upper cavity. There are three magnets fixed to absorb the charging case cover and earbuds.
The top structure of the lower frame is fixed with Hall elements.
Remove the screws, melt the solder joints between the earbud charging connector and the main board, and remove the main board unit.
The circuits on the motherboard side.
The circuit on the other side of the motherboard, the battery wire and the Hall element FPC are welded on the motherboard.
Silkscreen T18 018 TVS tube for input overvoltage protection.
LED indicators for feedback of bluetooth pairing and charging status.
Silkscreen R200 fuse.
TPS SY8815 bluetooth headset charging case solution, specially designed for bluetooth headphones, internally integrates a charging module and a discharging module. The charging current can be adjusted externally. The discharge module integrates two output current limiting switches, provides independent load presence detection and load insertion detection, and supports output current detection at the same time.
SY8815 discharge enable control, MCU can flexibly control the discharge function of the chip directly through EN. SY8815 integrates a single-line status code output, which is convenient for the chip to report the chip status to the MCU. SY8815 is very suitable for the design of bluetooth headset charging case, which greatly simplifies the peripheral circuit and components, and provides an easy-to-use solution for the application of charging case.
The peripheral power inductor of the power management chip cooperates with the power management chip to charge and discharge the battery.
Screen printing UwG voltage regulator IC.
XySemi XB5152J2SZ integrated lithium battery protection IC. The XB5152 ZR series products are highly integrated solutions for Li-ion/polymer battery protection. Contains advanced power MOSFET, high precision voltage detection circuit and delay circuit. Housed in an ultra-small SOT23-5 package with only two peripheral devices, it is an ideal solution for limited space.
The MCU microcontroller with silk screen printing AY0020801 is used for the overall control of the charging case.
Hall element FPC circuit.
The hall element with screen printing 8891q is used to sense the magnetic field change when the charging case is turned on/off, and then notify the charging case MCU and earbuds to pair or disconnect with the connected device, so as to realize automatic charging when entering the warehouse, and the function of connecting when the cover is opened.
The information on the label of the built-in rechargeable lithium-ion battery in the charging case, model: 761832A, rated capacity: 440mAh 1.67Wh, typical capacity: 450mAh 1.71Wh, charging limit voltage: 4.35Vdc, nominal voltage: 3.80Vdc, manufacturer: Chongqing VDL Electronics Co., Ltd., made in China.
Tear off the outer label, and the silk screen information on the inner cell, model: 761832APF3.
02/ OPPO Enco Free 3 earbuds teardown
Remove the back cover of the headset stem,
There is an FPC bluetooth antenna and a touch detection patch on the inside of the cover, and the silk screen model “SN-LHZ-R-V7”.
The internal structure of the headset stem is provided with a motherboard unit. The FPC of the internal components of the earbud head is connected to the motherboard through the BTB connector.
Flip open the connector and remove the motherboard.
FPC is connected to the BTB connector of the motherboard, model: OK-128GM016/2-35, from OCN.
Microphone acoustic structure, L-shaped anti-wind noise design, reduce the impact of wind noise.
The circuit on one side of the earbud motherboard.
The circuit on the other side of the earbud motherboard.
Screen printing 5CTR QAB0 touch detection IC.
The 24.000MHz crystal oscillator provides the clock for the bluetooth chip.
BES BES2600YUC ultra-low power Bluetooth audio SoC, supports dual-mode Bluetooth 5.3, LE Audio and multi-point connections. The chip has built-in dual-core STAR-MC1 CPU, BES self-developed dual-core BECO NPU, integrated 4MB/8MB Flash, high-performance PMU and Charger. Support adaptive leakage/wearing/environment/semi-open ANC noise cancellation and triple-mic AI ENC calls, with powerful application processing capabilities, effectively improving the single battery life of the earbuds.
Scientic SDHK1608HB4R7MT fully magnetically shielded precision wound inductors have significant advantages such as good efficiency, low noise floor, high sensitivity, and anti-magnetic interference. The top is high-density magnetic powder, which has higher magnetic permeability than traditional precision-wound inductors. The fully-enclosed magnetic shielding structure makes the magnetic force lines closer and optimizes the spatial interference to surrounding devices.
Metal dome connector to connect the bluetooth antenna.
Connect the metal dome of the touch detection patch.
BTB connector for FPC, model: OK-128GF016/2-35, from OCN.
The MEMS microphone of laser carving MF06 D138 is used for voice calls, voice control, noise cancellation and other functions to pick up sound, from MEMSensing.
Disassemble the earbud head cavity along the parting line.
The internal structure of the front cavity of the earbud, the battery is fixed by the frame.
Remove the battery and the fixing frame.
The inner structure of the frame is sealed with the front cavity, and the gap forms a bass duct, which effectively enhances the sense of low-frequency volume.
Sensors for the in-ear detection function are attached to the cavity wall.
Take out the battery, disconnect the nickel sheet of the battery and the FPC solder joint, and the circuit on the FPC side.
The circuit on the other side of the FPC.
The FPC board is equipped with WINSEMI WSDF23B2N2H lithium battery protection IC. It adopts DFN-1*1 ultra-small package, and has all the protection functions required by the battery, such as overcharge, overdischarge, overcurrent, and short circuit. Support CTL shipping mode, the standby current is less than 10nA during operation.
Button battery model: 115560, nominal voltage: 3.85V, energy: 0.165Wh, from VDL.
Take out the speaker. The internal structure of the front cavity of the earbuds is designed with a front cavity sound filtering system specially developed for the bamboo fiber diaphragm to improve high-frequency performance.
Take out the sound filter structure, and the in-ear detection sensor is pasted on the wall of the cavity below. There is a noise cancellation microphone inside the sound pipe.
Take out the FPC and noise cancellation microphone.
The FPC inside the earbud head and the connected component circuit.
The front diaphragm of the speaker unit is made of bamboo fiber material to make the treble dome, which greatly improves the high-frequency delicate hearing and effectively suppresses distortion.
After actual measurement, the speaker size is about 12.29mm.
The MEMS microphone of laser engraving ME48 D159 is used to pick up environmental noise from the ear. Combined with the microphone on the headset stem to pick up sound cooperatively and the noise cancellation algorithm, it can realize clear voice call effect and immersive music experience.
All components of OPPO Enco Free 3 true wireless noise cancellation earbuds.
03/ Summary
In terms of appearance design of OPPO Enco Free 3, the charging case is small and portable, with a round texture and a double-layer transparent shell design. The inner layer of the case cover is designed with texture, and the opening of the cover adopts a smiling curve, which makes the look and feel more lively and interesting. The handle-stem in-ear earbuds have a round body without edges and corners, making them comfortable to wear.
In terms of internal structure configuration, the built-in battery of the charging case is well protected, with a capacity of 440mAh, which comes from VDL. The motherboard adopts XySemi XB5152J2SZ integrated lithium battery protection IC to be responsible for battery charge and discharge protection. The TPS SY8815 charging case solution is responsible for the charge and discharge management of the battery. The charging current can be adjusted externally, and the discharging module integrates two output current limiting switches. And an MCU is responsible for the overall control of the charging case.
The earbuds is equipped with a bamboo fiber diaphragm dynamic driver, which is matched with a front cavity sound filter system and a rear cavity bass tube to comprehensively improve the high frequency and low frequency effects. A single earbud uses two MEMS microphones to pick up sound. The earbud has a built-in VDL 0.165Wh soft pack button battery, and uses WINSEMI WSDF23B2N2H lithium battery protection IC. The main control chip is BES BES2600YUC ultra-low power bluetooth audio SoC, which supports dual-mode Bluetooth 5.3, LE Audio and multi-point connections. Support adaptive ANC and AI call noise cancellation. The periphery adopts Scientic SDHK1608HB4R7MT fully magnetically shielded precision winding inductor to power the internal circuit.
Source: 52audio
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