omthing is a sub-brand of 1MORE Acoustics, focusing on providing users with smart digital and peripheral products that combine simple design and high practicability. Recently, omthing launched the first TWS headset product that supports active noise reduction——omthing AirFree 2 true wireless earphones, which has been fully upgraded in terms of appearance, texture and functional configuration.
The omthing AirFree 2 uses a contrasting color design, and the overall look is simple and stylish. The earphone is a handle-shaped in-ear design, and the body is small and light. The functional configuration is equipped with a 7mm graphene diaphragm dynamic driver and a Qualcomm QCC3040 bluetooth chip. Supports bluetooth 5.2, AAC, aptX high-quality decoding, active noise reduction (ANC), four-mic smart call noise reduction and wireless charging, etc.
52audio also teardown the omthing AirFree Pods and omthing AirFree true wireless bluetooth headset. Let’s take a look at the detailed dismantling report of this product.
|1. omthing AirFree 2 Charging case teardown
After unpacking, I learned about the appearance design of this product in detail. Let’s go to the disassembly and take a look at the internal structure configuration~
Pry open the charging cockpit, the components in the charging case are not fixed on the cockpit, but in the charging case housing.
At the bottom of the cockpit, there are four magnets for attracting earphones and charging case.
The charging case adopts a spring to increase the damping feel at the rotating shaft of the charging case.
The bottom frame of the cavity is fixed on the shell by four screws.
Remove the screws and take out the components in the charging case.
The main board unit is fixed on the top of the frame, and there is an FPC cable attached to the bottom of the main board, which is connected to the main board through the ZIF connector, and the two ends of the cable are charging thimble.
The bottom is the wireless charging receiving coil, and the battery is in the middle position, which plays a very good protective role.
The front LED indicator is also set on the FPC cable.
On the back is the Type-C charging interface.
Main board, battery and wireless charging receiving coil circuit.
FPC cable circuit.
LED indicator, supports multiple colors, used for feedback of charging case status.
Bluetooth pairing function button.
The Hall element of silkscreen 8691C notifies the headset to connect/disconnect with the paired device by sensing the magnetic field change (Hall effect) when the charging case cover is opened/closed.
Pogo pin connector for charging the headset.
Lithium-ion soft pack battery model 751830PL, rated capacity: 410mAh/1.51Wh, rated voltage: 3.7V.
The battery is equipped with a circuit protection board and an integrated protection IC, and there is a thermistor on the protection board for temperature detection.
The charging case front circuit of the motherboard.
The charging case circuit on the back of the motherboard.
ST STM8S003F3 is an 8-bit MCU with 8KB flash memory, 16MHz CPU, integrated EEPROM, used for charging case control.
The LPSemi LP5305 overvoltage and overcurrent protection IC also supports front-end protection of the lithium battery charger, disconnecting the charger input when the battery is overvoltage, providing a complete and comprehensive protection function.
According to 52audio, audio products from brands such as Xiaomi, OPPO, Huawei, Lenovo, Motorola, Realme, Edifier, QCY, JLab, Skullcandy, Boltune and other brands have adopted a large number of LPSemi power management solutions.
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 easily 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 information interaction needs of the charging compartment and the headset, and realize 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. 52audio learned in the previous disassembly that Belkin SOUNDFORM Freedom true wireless headphones also use this product.
The 2R2 inductor cooperates with ICP1106 for battery charge and discharge management.
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 pin for host fault control.
According to 52audio, the COPO wireless charging receiving solution has been widely adopted by Haylou, OPPO, Edifier, Realme, Baseus, Belkin, Sabbat, omthing, iWALK and other brands of TWS headsets.
|2. omthing AirFree 2 earphones teardown
Pry the earphones along the parting line.
The speaker, battery, and light sensor in the headphone head are connected to an FPC cable, and then connected to the motherboard.
The FPC cable is fixed on the cavity wall by double-sided adhesive, and the via hole is connected to the main board.
The circuit on the back of the FPC cable in the headphone head is reinforced and protected by transparent glue for the soldering points of the wires. The end uses a BTB connector to connect to the motherboard.
A battery protection IC with silk screen BE is set at the solder joint of the battery wire.
The back of the FPC cable.
Infrared optical distance sensor, used for in-ear detection function, realizes automatic pause when taking off, and automatic resume playing when worn.
The black filter of the optical in-ear detection sensor in the front cavity.
There is a baffle in the back cavity to isolate the main board and the battery.
On the front of the speaker unit, glue is fixed into the earphone cavity and protected by a metal shell.
The back of the speaker unit is provided with a tuning hole and is protected by a dust-proof net.
After actual measurement, the size of the speaker unit is about 7mm.
A steel button battery is used in the earphone, and a cushion is attached to one side of the battery.
Insulating tape is attached to the positive and negative nickel sheets. No parameter information is marked on the battery.
Pry open the back cover of the earphone and the internal structure of the cavity.
Take out the main board and the internal structure of the earphone handle cavity.
A shielding sticker is affixed to the main control chip on the cavity wall, and the bottom charging contact is directly welded to the main board.
The inner structure of the earphone handle cover, and the microphone acoustic structure at both ends, improve the sound reception performance. There is a bluetooth antenna and a touch sensor in the middle.
The front circuit of the headset motherboard.
The circuit on the back of the headset motherboard.
LY ICP1205 is a linear charging IC that supports two-way power line communication. It is a headphone analog front end tailored for the TWS headphone system. ICP1205 integrates functions such as programmable linear charging, power path management, carrier and transparent communication, headset transportation mode, etc., with extremely low operating power consumption and standby functions. The chip supports multiple complete protection functions, and supports bluetooth master firmware upgrade and data transmission functions.
At the same time, ICP1205 is matched with ICP1106 to support efficient charging mode. The output voltage of the charging compartment can be adjusted according to the voltage of the headset battery, increasing the conversion rate of the charging compartment battery by about 20%. It provides assistance for TWS earphones with long standby time, reduces the size of the charging compartment, and saves battery costs.
Silkscreen CI’s IC.
Silkscreen 0v48 IC.
Qualcomm QCC3040 BGA package ultra-low power bluetooth audio SoC. QCC304x supports bluetooth V5.2, supports Qualcomm aptX™ Adaptive audio coding, and integrates enhanced features such as stability, good sound quality, scalability, low latency and low bit rate audio transmission.
QCC304x chips can integrate active noise reduction technology and support cVc call noise reduction. Support Qualcomm TrueWireless™ Mirroring technology, left and right earbuds can be quickly switched in multiple usage scenarios. Voice assistant that supports touch or key to wake up the phone.
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.
The crystal oscillator of LaserDiao UB provides the clock for the bluetooth chip.
CHIPRISE BH7133B touch IC.
Laser carving 2122 7X04 MEMS microphone, used for voice call pickup, comes from Xingang Electronics. Two LED indicators are set up and down the microphone to indicate the working status of the headset.
Connect the metal dome of the touch sensor.
Xingang Electronics 2718 progressive sound noise reduction microphone, model SA2718T421-NB01, is used for active noise reduction and call noise reduction to pick up external environmental noise.
All components of omthing AirFree 2 true wireless noise canceling headphones.
The omthing AirFree 2 true wireless noise-cancelling headphones have a two-color collision design in appearance, which is simple and fashionable, and makes the whole machine more lively and unrestrained. The handle-shaped in-ear earphones are small and lightweight, weighing only 4.1g, and are matched with an ergonomic body curve design. They fit tightly and comfortably with the ear canal and are not easy to fall off.
In terms of internal circuits, the charging case supports two power input modes, wired and wireless. The cable uses Type-C interface input power. The LY ICP1106 power management chip provides charge and discharge management for the built-in 410mAh battery. It also supports transportation mode, and the standby power consumption can be as low as 1uA. Wireless charging uses COPO CP2021 high-integration 2.5W wireless charging receiver chip. It is also equipped with LPSemi LP5305 overvoltage and overcurrent protection IC, ST STM8S003F3 MCU microcontroller and so on.
In the omthing AirFree 2 headset part, the 7mm speaker, steel button battery, and infrared optical sensor in the headphone head are connected to an FPC cable, and then connected to the motherboard through the BTB connector. On the main board, LY ICP1205 linear charging IC is used to charge the built-in battery. The main control is Qualcomm QCC3040 low energy bluetooth audio SoC, bluetooth 5.2, supports aptX Adaptive audio coding, supports active noise reduction, cVc call noise reduction and other functions. And CHIPRISE BH7133B touch detection IC, etc.