Belkin SOUNDFORM Freedom true wireless headset is the second product launched by Belkin after entering the TWS headset field. The main selling point is to support the Apple Find My function, which can track and locate the charging case location in real time through the “Find My” APP on Apple iPhone and iPad. You can also make the headset play a prompt tone, which is convenient for users to quickly find the location of the headset when they have forgotten the location of the headset.
In terms of appearance design, both the SOUNDFORM Freedom charging case and earphones use piano baking varnish and matte two processes, which not only enhance the product texture, but also bring a comfortable holding and wearing experience. In terms of configuration, it adopts 7mm double-layer composite drive unit, equipped with Qualcomm’s new generation bluetooth chip, supports bluetooth 5.2, AptX technology, dual-mic call noise reduction, IPX5 anti-sweat and splash-proof, wireless charging and other functions, with 36 hours of super long Battery life.
52audio also disassembled Belkin SOUNDFORM ELITE smart speakers and Belkin ROCKSTAR Apple Lightning headphones. Let’s take a look at the internal structure of this product.
|1 Belkin SOUNDFORM Freedom unboxing
The packaging box continues Belkin’s classic design style, with a large frontal display of the product appearance. The information has the “belkin” brand LOGO, product name: SOUNDFORM Freedom true wireless headset, three product features highlights: Belkin’s iconic sound, clear call, 8+28h battery life, and the Apple Find My logo at the bottom right.
On the back of the box, the product features are introduced in detail, and there are pictures of models wearing scenes.
At the bottom of the box are part of the information and various certification marks of product distributor Belkin Trading (Shanghai) Co., Ltd.
The accessories in the box include USB-A to Type-C charging cable, two pairs of silicone eartips of different sizes, product manual and user guide.
The charging case adopts a square design, piano paint process, and the “belkin” brand LOGO is engraved on the top.
The bottom of the charging case shows part of the product parameter information, product model: AUC002, input: 5V-1000mA, charging voltage 3.7V, capacity 520mAh/1.924Wh. The small hole on the right is the sound hole of the Find My function.
The charging case has a chamfer at the front opening for easy opening. There is an indicator light at the bottom for feedback of the charging case status.
There is a Type-C charging interface and a function button on the back of the charging case, which are used to restore factory settings and turn on/off the Find My function.
Open the charging case, the headset is placed flat in the charging case, and it is attracted by a magnet.
Numerous certification marks are printed on the inside of the charging case cover.
A wireless charging logo is designed between the two headset cockpits.
Metal thimble for charging earphones.
The overall appearance of Belkin SOUNDFORM Freedom true wireless earbuds.
After actual measurement, the overall weight of the SOUNDFORM Freedom true wireless headset is about 59.6g.
The charging case weighs about 48.9g.
The weight of the two headphones is approximately 10.6g.
Use a portable power tester to perform a wired charging test on SOUNDFORM Freedom. The charging power is about 2.79W.
Use a portable power tester to perform a wireless charging test on SOUNDFORM Freedom. The charging power is about 2.15W.
|2. Belkin SOUNDFORM Freedom teardown
After unpacking, we have learned about the overall appearance design of SOUNDFORM Freedom. Let’s enter the disassembly part to take a look at the internal design of this product.
Charging case teardown
Pry open the headset charging case and take out the charging cockpit.
The inner structure of the function keys is provided with a sponge cushion for buffering.
A fine dust-proof net is arranged inside the prompt sound opening.
Indicator light guide.
At the bottom of the cockpit of the charging box, there is a circular wireless charging receiving coil.
On the back of the cockpit, the Type-C charging interface is set on the motherboard.
The battery unit can be seen from the front.
A small buzzer board is fixed on the side of the charging cockpit.
The components are connected to the motherboard through wire connectors.
The charging case cockpit motherboard circuit.
The wireless charging receiving coil is provided with magnetic isolation stickers and fixed on the plastic plate.
The wireless charging receiving coil is fixed to the plastic plate.
Circuit on the motherboard side.
Circuit on the other side of the motherboard.
Type-C charging interface female socket, through-hole welding.
Pogo pin for charging earphones.
The voltage regulator IC of silk screen D00S.
Two LPSemi LPM2301 2.6A PMOS with silk-screen printing A1SHB are the higher current version in the industry, with enough margin to ensure safety. It is packaged in SOT-23 and used as a switch for charging the earphones.
Nuvoton Nuvoton N76E003AQ20 main control single-chip microcomputer, used for lid opening detection and power display functions.
COPO CP2021 highly integrated 2.5W wireless charging receiver chip, in line with WPC 1.2.4 version Qi protocol. The output voltage is 5V, and the output current is adjustable, up to 500mA; integrated external power input detection function; integrated over-temperature, over-voltage and output over-current protection; integrated temperature monitoring, charging completion and multi-function NTC control for host failure control foot.
According to 52audio, the COPO wireless charging receiving solution has been widely adopted by Haylou, OPPO, Edifier, Realme, Baseus, Sabbat, omthing, iWALK and other brands of TWS headsets.
COPO CP2021 detailed information.
LY ICP1106 power management chip integrates switch charging, Boost synchronous boost, power path management, binaural independent plug detection, two-way communication, OVP, OCP protection and other functions, with powerful performance, high integration, simple peripheral circuits, etc.
The charging voltage, charging current, and output voltage of ICP1106 can be flexibly configured through I2C, which can conveniently realize TWS fast charging and efficient charging; at the same time, it supports two communication modes of power line carrier two-way communication and UART two-way communication, which can reliably meet the requirements of charging warehouse and The information interaction requirement of the headset realizes the intelligent control of the headset and the charging compartment.
ICP1106 also supports transportation mode, the standby power consumption can be as low as 1uA, and supports 0V, 2.4V, battery voltage and other voltage output standby modes. With its powerful functions and unique technology, ICP1106 has been recognized by a large number of customers once it was launched. There will be more product applications to meet with you, let us look forward to it.
In the cockpit bottom structure, four magnets are used to absorb the earphones and charging case cover.
Lithium-ion soft pack battery model ZWD802030K, capacity: 520mAh/1.924Wh, voltage 4.2V/3.7V.
The battery is equipped with an integrated circuit protection board, which is responsible for protection functions such as overcharge, overdischarge, and overcurrent.
The front of the buzzer small board is used to send out the prompt tone of the search function.
The back of the buzzer board.
Another PCB board in the charging case is the bluetooth search module, which is connected to the main board through the ZIF connector.
Front circuit of small board.
Ceramic bluetooth antenna.
The regulator IC of silk screen 7TW.
IC with silk-screened QR code.
Nordic N52832 multi-protocol general-purpose SoC, supports bluetooth 5.0, supports NFC, ANT and 2.4 GHz proprietary protocols, and is used for long-distance positioning of the “Find My” function and reading of information after loss. Its core is the ARM Cortex M4 CPU running at 64MHz, which can handle demanding applications and communication tasks in a short period of time so that the CPU can continue to process more tasks or return to sleep mode, thus saving valuable battery energy.
All SoCs in the nRF52832 and nRF52 series are basic flash memory, which is very suitable for device firmware upgrade (DFU). DFU provides full flexibility and control for the firmware running in your product, and can enable new security updates, fix errors, and add features on site.
According to 52audio, Apple AirTag wireless tracker also uses this chip, and Apple HomePod mini smart speaker also uses the Nordic nRF52 series chip.
The crystal oscillator of the laser carving T048A provides the clock for the Nordic N52832 multi-protocol universal SoC.
The SOUNDFORM Freedom earphone is a handle-shaped in-ear design, and the overall appearance is very distinctive. The curve of the headphone head adopts an elliptical design, without any prominent structural design around it, and it fits closely to the ear canal, and is comfortable and stable.
The handle of the earphone is an elliptical cylinder with a “belkin” brand LOGO on the side.
The bottom of the headset is equipped with a tapered structure cover, the middle is the call microphone, and there is an indicator light next to it.
The back of the headset is also the touch operation area.
The microphone opening on the side of the earphone head is used for call noise reduction function, which is covered with a metal dust-proof net to prevent foreign objects from entering the cavity.
There are two gold-plated charging contacts on the inside of the earphone, and the optical sensor opens the window in the middle.
Sound cavity pressure relief hole.
The sound mouth of the earphone is protected by a metal mesh cover to prevent foreign objects from entering the sound cavity.
Pry the earphones along the parting line.
The battery cell is welded to the FPC board through wires, and the internal components of the front cavity are connected to the FPC board through the BTB connector. All glued and fixed.
Open the BTB connector, the internal structure of the back cavity.
The internal structure of the front cavity, the speaker is welded to the FPC board through a wire.
Remove the FPC board, below is the window of the ear detection sensor and the magnet used to adsorb the charging case.
The loudspeaker is fixed in the output tube by a large amount of glue.
The FPC board circuit in the front cavity, the optical sensor is protected by a rubber cover to prevent light leakage and improve accuracy.
Optical in-ear detection sensor.
After actual measurement, the size of the speaker unit is about 7mm.
The rear cavity battery and the FPC board are connected to the main board unit in the earphone handle through a flat cable and BTB.
Touch sensor on the back cavity wall.
On the side of the battery is a call noise reduction microphone, which is covered by a rubber cover to improve the radio performance.
The MEMS silicon microphone of LaserDiao MC50 is used for call noise reduction function.
The integrated battery protection IC of silk screen 9u13.
The IC of silk screen C1.
A steel button battery is used inside the earphone.
The two-dimensional code is printed on the front of the steel shell button battery.
The back side is connected by a nickel sheet. There is no clear silk-screened battery information.
Touch the foil and use double-sided tape to fix it inside the housing.
Remove the motherboard from the earphone handle.
Comparison of the size of the motherboard and the RMB coin.
Circuit on the motherboard side.
Circuit on the other side of the motherboard.
The call microphone and LED indicator at the bottom of the earphone handle are connected to the motherboard through an FPC cable.
SINOMCU MC9934 8-bit single-chip microcomputer, used to trigger a reset and send a bluetooth signal again when the bluetooth headset fails to connect to ensure that the bluetooth does not crash. At the same time, it has ultra-low standby power consumption and extends the battery life of the bluetooth headset.
MC9934 adopts DFN8 package, has 8-bit CPU core, 1K×14-bit OTP type program memory and 50-byte SRAM general data memory; built-in high-frequency and low-frequency RC oscillator, used as the system clock source at high or low frequency ; There are two working modes: running mode and sleep mode; internally equipped with self-oscillating watchdog counter and timer.
The touch IC of the silk screen 7812C detects the touch operation on the earphone handle housing.
Ceramic bluetooth antenna.
Qualcomm QCC3040 bluetooth audio SoC, QCC304X series bluetooth audio SoC supports bluetooth 5.2, supports Qualcomm aptX™ Adaptive codec, can automatically adjust based on the type of content played on the terminal to provide the best sound quality or low latency, bring Immersive video and gaming wireless listening experience.
This series of chips also supports the new Qualcomm TrueWireless™ Mirroring technology, and the left and right earbuds can be quickly switched in multiple usage scenarios. In addition, Qualcomm QCC304x series bluetooth audio SoC also supports cVc call noise reduction technology, which can wake up the phone’s voice assistant through touch or button.
According to 52audio, well-known brands such as Anker, Bose, Beyerdynamic, B&O, Cleer, Edifier, Klipsch, Libratone, Xiaomi, Microsoft, OPPO, vivo, Sony, 1MORE and other well-known brands have adopted a large number of Qualcomm bluetooth audio SoCs.
Qualcomm QCC3040 detailed information.
All components of Belkin SOUNDFORM Freedom true wireless earbuds.
Belkin SOUNDFORM Freedom true wireless earphones are designed with a piano paint process, and the overall appearance is very clean and has a strong texture. The headset has an almost elliptical curve that fits closely with the ear canal when worn, providing a comfortable and stable wearing experience.
In terms of internal circuits, the charging case is composed of three parts: the main board, the bluetooth module and the buzzer board. The charging case has a built-in 520mAh lithium-ion battery, is equipped with a circuit protection board, and supports input power in both wired and wireless modes. The wired input uses the LY ICP1106 power management chip, and the wireless uses the COPO CP2021 wireless charging and receiving chip. Nuvoton N76E003AQ20 main control single-chip microcomputer, used for functions such as lid opening detection and power display. And two LPSemi LPM2301 2.6A PMOS, used to charge the headset switch.
The bluetooth search module of the charging box is equipped with a ceramic Bluetooth antenna and a Nordic N52832 multi-protocol universal SoC, supports Bluetooth 5.0, supports NFC, ANT and 2.4 GHz proprietary protocols, and is used for long-distance positioning and lost information for the “Find My” function Read.y” function Read.
In the Belkin SOUNDFORM Freedom earbuds part, the speakers in the front cavity and the charging board are connected to the FPC board in the rear cavity through the flat cable and BTB, and then to the main board through the flat cable and BTB. The rear cavity cable is connected with a battery, a touch sensor and a call noise reduction microphone. The motherboard uses Qualcomm QCC3040 bluetooth audio SoC, supports bluetooth 5.2, and supports Qualcomm’s multiple audio technologies. SINOMUC MC9934 8-bit single-chip microcomputer, used to trigger a reset to re-transmit the bluetooth signal when the bluetooth headset fails to connect to ensure that the Bluetooth does not crash.