As a senior HiFi audio brand in China, FiiO’s products cover lossless music players, headphone amplifiers, bluetooth audio receivers, earphones and many other categories. Provide easy-to-use, fun and pleasant-sounding audio products for consumers who love music and pursue fashion and high-quality life.
FiiO FW5 is FiiO’s new generation flagship TWS earbuds. The appearance adopts the design of FiiO FD5/FD7/FDX series, which is very characteristic and recognizable. In terms of functional configuration, it inherits FiiO’s pursuit of high-quality audio experience, integrates high-end bluetooth chip, independent DAC chip and professional acoustic architecture, and provides a full-link HiFi experience.
The earbud is equipped with an acoustic structure of a dynamic driver and two armature drivers to ensure low-frequency extension and mid-to-high frequency detail performance. It adopts Qualcomm QCC5141 bluetooth audio SoC, obtained Snapdragon Sound certification, and supports aptX Adaptive and LHDC high-definition bluetooth formats. The built-in independent DAC chip provides high-performance decoding capability, high signal-to-noise ratio, high dynamic range and low distortion. Built-in dual microphone units, support cVc echo cancellation and noise reduction technology, provide clear calls. It also supports independent volume control, IPX4 waterproof, a single battery life of up to 7 hours, and a comprehensive battery life of 21 hours.
We have teardown the FiiO UTWS5, FiiO EH3 NC, FiiO M3 Pro player, FiiO μBTR bluetooth audio receiver, FiiO UTWS1 bluetooth receiver and other products before. Let’s take a look at the detailed teardown report of this product.
01/ FiiO FW5 charging case teardown
Teardown the snap-fit charging case shell, and take out the charging cockpit structure.
The bottom structure of the charging cockpit, the main board is fixed by screws, and the battery is attached to the main board.
The LED indicator light structure on the front of the cockpit.
Remove the battery, the main board structure below, and the battery wires are soldered to the main board.
Remove the screws, take out the motherboard unit, and connect an FPC cable to the indicator light and the Hall element.
Remove all the components on the charging cockpit, and there are three magnets on the bottom of the cockpit to absorb the charging case cover and earbuds.
The circuit on the side of the motherboard of the charging case.
The circuit on the other side of the charging case motherboard has reserved pads for wireless charging components.
TPS SY8821 power management SoC, internally integrates charging module and 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. The chip integrates NTC protection function to charge and discharge the battery more safely.
SY8821 can match the requirements of all bluetooth masters for power characteristics. 5V normal open and drop voltage modes are optional, the output power consumption is as low as 3uA, and 1~4 lights can be flexibly configured. There is no need to customize the part number, buttons and Hall control are optional. Without an external MCU, a single chip can realize the application design of the charging compartment, which greatly reduces the risk of stocking up.
According to 52audio, TPS power management chips have been adopted by Xiaomi, OPPO, OnePlus, realme, 1MORE, Baidu, Edifier, JBL, HARMAN, Lenovo and other brands.
The integrated power inductor is responsible for the charge and discharge management of the battery with the power management chip.
Screen printing 1802U overvoltage and overcurrent protection IC.
Silkscreen Z35 1Y IC.
Pogo Pin connector for charging/communicating earbuds.
The motherboard is connected to the ZIF connector of the cable.
The side circuit overview of the Flat cable.
The circuit on the other side of the Flat cable.
Four LED indicators are used to feedback the remaining power and charging status of the charging case.
The Hall element of silk screen 6207 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 the connected device.
The charging case built-in lithium battery. Battery model: SUNDA 602328, capacity: 380mAh 1.4Wh, voltage: 3.7V, production date: September 20, 2022.
The battery protection board circuit is equipped with Y1AE lithium battery protection IC and 8205A MOS tube.
02/ FiiO FW5 earbuds teardown
Enter the teardown part of the earbuds and remove the cover on the back of the earbud.
The FPC antenna is set on the inside of the cover, the silk screen model is “FW5-ANT-L-V01”, and the exposed copper is connected to the main board.
The main board inside the headphone cavity is fixed by screws, and there is a BTB connector on the main board to connect other components, and the main control is covered with a sponge pad for isolation.
Remove the screws, flip open the connectors, and take out the motherboard. A battery is fixed under the main board, and the battery is welded to the main board through wires.
The microphone unit structure on the wall of the earbud cavity, the independent cavity is sealed to improve the sound collection performance.
The circuits on the motherboard side.
The circuits on the other side of the motherboard.
BTB connector socket for connecting cables. As far as we know, from OCN, model number: OK-114GF008-04.
Qualcomm QCC5141 bluetooth Audio SoC is an ultra-low power single-chip solution. It adopts WLCSP package and has smaller volume. Supports Bluetooth 5.2 and Qualcomm Snapdragon Sound technology with programmable DSP, optimized for true wireless earbuds and hearing devices.
Qualcomm QCC5141 combines high-performance audio with low power consumption, supports 24bit/96KHz high-resolution audio and aptX/aptX-Adaptive codec. It supports aptX Voice optimized call voice and the eighth-generation Qualcomm cVc echo cancellation and noise suppression technology. Support Qualcomm’s adaptive active noise cancellation function (not yet applied to FiiO FW5), including feedforward, feedback, hybrid and adaptive, and support third-party innovation through Qualcomm extensions.
According to 52audio, there are currently TWS earbuds, over-ear headphones, neck-mounted bluetooth earphones, smart speakers, smart audio glasses and other audio products that have adopted Qualcomm bluetooth audio SoC.
The crystal oscillator that provides the clock for the bluetooth chip.
The MEMS microphone of Leidiao FI4J is used for the call noise reduction function to pick up the environmental noise.
The silk screen 6AJI Q1J memory is used to store bluetooth configuration and other information.
An LED indicator for feedback of bluetooth pairing and charging status.
The metal dome used to connect the FPC bluetooth antenna.
The micro buttons on the side of the motherboard are used to control various functions.
AKM AK4332 low power DAC chip is a low power consumption advanced 32-bit high sound quality mono audio DAC. Built-in headphone amplifier with four types of 32-bit digital filters for better sound quality, low distortion characteristics and wide dynamic range. AK4332 accepts PCM data, PDM data and DSD data. Adopt 30-Pin CSP package, small size, save space.
Screen printing 1N B1 lithium battery protection IC.
Screen printing 3C regulator IC.
Another laser engraving FI4J MEMS microphone is used for voice call pickup.
Take out the battery, the internal structure of the front cavity of the earbuds.
The steel shell button battery is used inside the earphone, which is wrapped and protected by high-temperature insulating tape.
Tear off the tape wrap, and disconnect the cable that connects the battery to the motherboard.
The earbud has a built-in steel shell button battery model: CP1254AA, voltage: 3.7V, engraved with a QR code for product traceability.
Remove the middle frame of the earbuds.
The speaker wire inside the headphone cavity and the power input unit cable are connected to the FPC board, and then connected to the main board through the cable.
Open the connector and take out the speaker and FPC board.
There are two armature drivers inside the sound tube, which are respectively connected to the FPC small board through enamelled copper wires. By placing it close to the tuning nozzle and closer to the eardrum during use, it can effectively reduce the loss of high frequency transmission.
The front of the dynamic driver adopts DLC dome + PU overhang diaphragm, which provides better dynamic response, sound field, transient response and resolution for earbuds.
On the back of the dynamic driver, there is a tuning hole in the middle, which is protected by a dust filter.
After actual measurement, the size of the speaker is about 10.48mm.
FPC small board circuit.
Female BTB connector for connecting the power input unit, from OCN, model: OK-114GF008-04.
The male BTB connector for connecting the motherboard, model: OK-114GM008-04, from OCN.
Take out the armature driver and the power input unit, and there are opposite-sex magnets inlaid on the wall of the cavity for adsorption and fixation with the charging case. The inside of the tuning hole and the sound outlet are protected by waterproof and sound-permeable mesh.
Metal connector for earbud charging/communication.
The BTB connector male seat connecting the connector cable to the FPC small board, model: OK-114GM008-04, from OCN.
The two armature drivers inside the earbuds are fixed together by glue.
The armature driver sound hole.
The two armature drivers use the same model, laser engraving model: 33518, from Knowles.
All components of FiiO FW5 true wireless earphones.
In terms of appearance, the charging case of FiiO FW5 has a matte texture, the body curve is round and comfortable to hold, and the design of 4 indicator lights can provide more intuitive feedback on the remaining power information. The bean-shaped in-ear earbuds are treated with two kinds of metal-like and frosted processes, which effectively improve the product texture and recognition. Equipped with 6 pairs of silicone eartips to meet individual needs, the HS18 eartips provide a more comfortable wearing experience.
In terms of internal structure and configuration, the charging case includes a motherboard, a battery and an FPC cable connecting the indicator light and the Hall element. The built-in lithium battery has a capacity of 380mAh and is equipped with a battery protection board for protection. The TPS SY8821 power management SoC is used on the main board to manage the charging and discharging of the battery. The charging current can be adjusted externally. The discharging module integrates two output current limiting switches and NTC protection function to charge and discharge the battery more safely.
The internal structure design of the earbud is layered and orderly, using 10mm DLC dome + PU suspension edge diaphragm dynamic driver + two Knowles armature drivers. Two MEMS microphones are used for voice call pickup. The main control chip is Qualcomm QCC5141 bluetooth audio SoC, which supports Bluetooth 5.2 and Qualcomm Snapdragon Sound technology, and has the characteristics of high-performance audio and low power consumption. The independent DAC adopts the AKM AK4332 chip and built-in headphone amplifier to provide better sound quality, achieve low distortion characteristics and wide dynamic range.