In recent years, Lenovo has not only worked hard on its main business PC computer, but also introduced terminal products such as smart phones, bluetooth headsets, smart speakers, and smart wearable devices. In the field of TWS earbuds, Lenovo has launched a number of series of products, which have a very good sales performance due to their high cost performance.
Lenovo QT83 is a handle-shaped semi-in-ear TWS earbuds of Lenovo, which has a light and comfortable wearing experience. The headset has a built-in bluetooth 5.0 chip, supports dual-channel connection, and supports single and dual ear mode. The headset adopts touch operation, supports a variety of control modes, plus and minus volume, voice wake-up and other functions.
Previously, 52audio had teardown the Lenovo TC03, Lenovo ThinkPlus TrackPods, Lenovo S1, Lenovo ThinkPad bluetooth speaker. Let’s take a look at the dismantling report of this product.
|1. Lenovo QT83 Charging case teardown
Enter the disassembly part, pry open the charging cockpit, and take out the internal structure.
The main board is fixed at the bottom of the charging cockpit, and a battery unit is arranged on one side.
An FPC cable on the other side is provided with LED indicators and Hall elements.
The motherboard is fixed on the bottom of the charging case with screws, and the FPC cable is connected to the motherboard through the ZIF connector.
Remove the screws, open the cable, and remove the motherboard and battery unit.
The end of the FPC cable is fixed by the positioning column.
A circular magnet used to attract headphones.
A square magnet used to adsorb the charging case cover.
The FPC cable circuit is equipped with three LED indicators and one Hall element.
Silk-screened Hall element of Hy9tA. Charging case The magnetic field changes when the lid is opened and closed will be sensed by the Hall element, and the charging case will be notified that the MCU and headset are paired or disconnected with the connected device.
The charging case is a circuit on one side of the main board, and the Type-C charging interface is soldered in the middle of the main board.
A list of the circuits on the other side of the main board, and the positive and negative wires of the battery are welded to the main board.
Injoinic IP5516 charging case management SoC, integrating MCU, boost converter, lithium battery charging management, battery power indicator, 5V one-way communication and other functions, provides a complete power solution for the TWS bluetooth headset charging bin.
IP5516 supports 300mA synchronous boost output, 500mA linear charging, adaptive input current, supports high-voltage platform battery, built-in ADC to calculate battery power, supports 1-4 LEDs or 5-6pin 188 digital tube power display. The high integration and rich functions of IP5516 enable it to require very few peripheral components during application, and effectively reduce the size of the overall solution and reduce the BOM cost.
According to 52audio, TWS headset charging cases of Edifier, Nokia, JLab, Hiby, Baseus, Pioneer, PIHEN and other brands have adopted Injoinic power management solutions.
2R2 boost inductor, used to boost the battery output to charge the earphones.
Type-C charging interface female socket.
The silkscreen 350EB lithium battery protection IC is used for battery overvoltage, overcurrent and short circuit protection.
Pogo pin connector for charging the earphones.
Lithium-ion soft pack battery model: crx 802040, capacity: 650mAh/2.405Wh, voltage: 3.7V, factory date: October 20, 2020.
The wires are welded to the positive and negative nickel sheets of the battery, and the battery protection chip is on the charging case circuit board.
|2. Lenovo QT83 earphones teardown
Enter the earphone part and pry open the earphone cavity along the moulding line.
Speaker unit in the front cavity.
Inside the back cavity is a soft pack battery.
Take out the battery to see the main board unit. The speaker and battery wires are soldered to the motherboard.
The speaker is fixed in the front cavity by double-sided tape.
A close-up of the inside of the pressure relief hole in the front cavity, protected by a fine dust-proof net.
The size of the speaker is compared with the RMB coin.
After actual measurement, the size of the speaker unit is about 13mm, which is consistent with the official publicity.
Lithium-ion soft pack battery model: YD501012, capacity: 40mAh, voltage: 3.7V.
The magnet inside the earphone is used to attract the charging case.
Take out the motherboard, a close-up of the conductive cloth at the bottom of the earphone, for touch operation.
Circuit on the motherboard side.
Circuit on the other side of the motherboard.
A close-up of the connector at the end of the motherboard that is used to charge the headset.
Close-up of ceramic bluetooth antenna, used for bluetooth signal transmission.
BLUETRUM AB5376A bluetooth audio SoC, AB5376A is mainly aimed at the TWS headset market, the chip has a 32-bit RISC-V processor, supports DSP instruction set, and the maximum operating frequency is 125MHz. The chip adopts QFN20 3×3 small package, which is suitable for all kinds of TWS small earphones.
AB5376A is specially designed for TWS earphone applications. The chip is highly integrated and the PCB peripheral materials are streamlined. Built-in 5V charging contact single-wire communication, built-in lithium battery charging management circuit, suitable for smart charging warehouse applications. The communication protocol supports bluetooth 5.0 EDR/BLE. Supports seamless switching between primary and secondary ears. The call part has a built-in single MIC ENC noise reduction/AEC echo cancellation algorithm. The original factory provides configurable programming tools to facilitate customers’ products to be quickly put into the market.
According to 52audio, brands such as Lenovo, Philips, 360, Transsion, Fantini, etc. have adopted BLUETRUM solutions in large numbers.
The MEMS microphone of LaserDiao MC39 B151 is used for voice call pickup.
Two LED indicators and microphones of different colors, surrounded by black sponge to prevent light leakage and sealing.
The metal piece connected to the touch sensor on the motherboard.
Laser carving LCC 26.000 crystal oscillator provides the clock for the bluetooth chip.
The IC of the silk screen 42396.
Silk-screen 350CB battery protection chip.
All components of Lenovo QT83 bluetooth headset.
In appearance, the charging case of the Lenovo QT83 bluetooth headset adopts a vertical rounded square design. The body feels smooth and round, and can be opened and closed with one hand. The three LED indicators provide more intuitive feedback on the remaining power of the charging case. The earphone is a handle-shaped semi-in-ear design, weighs only 3.9g, and is light and comfortable to wear; the earphone adopts touch operation and is convenient to use.
In terms of internal circuits, the charging case has a built-in 650mAh lithium-ion soft pack battery, the Type-C charging interface is used on the motherboard, the INJOINIC IP5516 charging case management SoC, integrated MCU, boost converter, lithium battery charging management, battery power indicator, 5V One-way communication and other functions provide a complete power solution for the charging case. An FPC cable connects the LED indicator and the Hall element for automatic connection/disconnection.
In the Lenovo QT83 headset part, a 13mm large dynamic driver and a 40mAh soft pack battery are used in the headphone head, which are connected to the motherboard through wires. On the motherboard, the main control chip is BLUETRUM AB5376A bluetooth audio SoC, supports bluetooth 5.0, supports seamless switching between main and sub headphones, and single MIC ENC noise reduction/AEC echo cancellation algorithm.