boAt Airdopes 131 true wireless earphones teardown

boAt is a local brand of consumer digital products in India. Its products include earphones, speakers, wearable products, speakers, travel chargers and high-end cables. Relying on strong manufacturing capabilities in China, with good product positioning, good customers With a sense of experience, superior competitive performance and price, 2020 ranks first in the Indian personal audio market share.

boAt Airdopes 131 is a product of boAt’s Airdopes true wireless headset series. It adopts a handle-shaped semi-in-ear design, a 13mm moving coil unit, bluetooth 5.0 audio chip, support for multi-function control, wake-up voice assistant, etc. Function, with an overall battery life of 3+12 hours. Let’s take a look at the internal structure configuration of this product.

|1. boAt Airdopes 131 Charging case teardown

After reading the unpacking, we learned in detail about the design of this product, and now we will enter the disassembly part.

Pry open the charging case cockpit and take out the internal structure.

One FPC cable is provided in the circuit on one side of the charging cockpit.

The circuit on the other side of the charging cockpit is fixed with a battery unit.

The main board is fixed at the bottom of the cockpit by screws, the FPC cable is connected to the main board through the ZIF connector, and the battery wire is welded to the main board.

Remove the motherboard and battery, two circular magnets on the cockpit are used to attract the earphones. The middle FPC board is a Hall element, which is used for automatic connection when opening the cover.

FPC cable circuit.

3 LED indicators of different colors.

For the Hall element of silk-screen Hv1SA, the magnetic field changes when the charging case cover is opened and closed will be sensed by the Hall element, and then the charging case will be notified that the MCU and headset are paired or disconnected with the connected device.

The main configuration in the charging case.

charging case Built-in battery model: crx 802040, capacity: 650mAh/2.405Wh, voltage: 3.7V.

The wire connected with the main board is welded on the nickel sheet, and the protection chip is arranged on the main board.

The circuit on the front of the motherboard.

The circuit on the back of the motherboard.

Type-C charging interface female socket.

INJOINIC IP6816 TWS headset charging compartment management SoC is a multifunctional power management SoC that integrates Qi wireless charging and receiving, 5V boost converter, lithium battery charging management, and battery power indicator. It supports automatic detection of dual-channel headsets independently in storage, 1 -4LED breathing light effect and 188 digital tube power display, while supporting customized 5V communication function, providing a complete power solution for wireless charging TWS bluetooth headset charging compartment.

The high integration and rich functions of IP6816 enable it to require very few peripheral components in application, and effectively reduce the size of the overall solution and reduce the BOM cost.

According to 52audio, there are already a large number of TWS headset charging cases of Edifier, JLab, HiBy, Baseus, Pioneer, PIHEN, BULL, AUKEY, MPOW and other brands that use INJOINIC power management solutions.

2R2 boost inductor, used to boost the battery output to charge the earphones.

ZIF connector, connect the Hall element FPC cable.

There is a lithium battery protection IC with silk screen 345EB at the position of the battery wire welding point, which is used for battery overvoltage, overcurrent and short circuit protection.

The pogo pin connector on the motherboard for charging the headset.

|2. boAt Airdopes 131 earphones teardown

Pry open the earphone cavity along the parting line.

The loudspeaker in the front cavity is fixed by glue, and there are multiple tuning holes on the right side, which are protected by a dust-proof net.

The soft-packed battery is placed in the back cavity and wrapped with yellow insulating tape.

Take out the speaker, the pressure relief hole of the front cavity is protected by a fine dust-proof net.

The front of the speaker.

After actual measurement, the speaker size is about 13mm.

The battery and the speaker are respectively soldered to the motherboard through wires, and the solder joints are glued for insulation reinforcement.

The magnet on the cavity wall is used to adsorb the charging case.

The headset has a built-in soft pack battery model JYZ501012, rated capacity: 40mAh/0.148Wh, rated voltage: 3.7V, from Shenzhen Jin Yu Zhou energy Co., Ltd..

The front circuit of the headset motherboard.

The circuit on the back of the headset motherboard.

The micro buttons on the main board are used for various control functions.

Laser carving MC48 B113’s MEMS silicon microphone is used for voice call pickup. There are two LED indicators of different colors on the left.

JL AD6976D bluetooth audio SoC, can support bluetooth 5.1, support AAC, SBC codec. Built-in 32-bit DSP, the processor runs at a frequency of up to 160MHz, supports noise suppression and echo cancellation, and supports multi-band equalizers. Support single/dual microphone noise reduction, this product adopts dual-mic noise reduction scheme and Jerry’s self-developed dual-mic ENC noise reduction algorithm. Support two-way analog microphone amplification, built-in microphone bias. Built-in dual touch function.

JL AD6976D supports 24/48KHz audio, built-in step-down circuit and voltage regulator circuit, used for internal digital and analog circuit power supply. Adopt 4*4mm QFN32 package.

According to 52audio, the bluetooth audio products of F&D, Tezo, Philips, Motorola, Amazon, Lenovo, MAOKING, Xiaomi, Baseus, SOAIY, MEES and other brands have adopted the JL solution. JL also released the AC700N series TWS solution this year.

Ceramic bluetooth antenna on the motherboard.

The metal copper pillar connector at the end of the motherboard for charging the earphones.

The 24.000MHZ crystal oscillator provides the clock for the bluetooth chip.

Silkscreen XBac’s integrated lithium battery protection IC.

All components of boat Airdopes 131 true wireless earphones.

|3. Summary

The boAt Airdopes 131 true wireless headset adopts an ergonomic semi-in-ear design with a weight of only 3.8g, providing a very comfortable wearing experience. The vertical charging case can be turned on with one hand, and the 3 LED indicators can provide more intuitive feedback on the charging case status.

The internal circuit of the charging case is very streamlined, with a built-in 650mAh soft-pack battery. Using Type-C interface input power, INJOINIC IP6816 power management SoC provides a complete TWS headset charging bin solution. It integrates a 5V boost converter, lithium battery charging management, supports automatic detection of dual-channel earphones, independent warehousing, 1-4 LED breathing light effects and 188 digital tube power display, and supports customized 5V communication functions. Only a few peripheral components are required, which effectively reduces the size of the overall solution and reduces the BOM cost. To

The boAt Airdopes 131 headset uses a 13mm large dynamic driver and a 40mAh soft pack battery inside. The main control chip is AD6976D8 bluetooth audio SoC, supports bluetooth 5.1, supports AAC encoding and decoding, noise suppression and echo cancellation, and has built-in dual touch functions. A MEMS microphone for voice call function.

Source: 52audio