Google Pixel Buds 2 true wireless earbuds are the latest generation of TWS earbuds under Google. Compared with the previous generation, the wire is completely abandoned and a brand-new design has been made. The distinctive appearance also won the 2021 Red Dot Design Award, which has been loved by many consumers.
Google Pixel Buds 2 true wireless earphones are very unique in design. The charging case adopts a vertical oval shape, which is easy to open. The headset is shaped like a “snail” and is ergonomically designed to provide a very comfortable wearing experience. It is equipped with 12mm high-dynamic speakers, accelerometer, infrared detection sensor, supports Hey Google quick wake-up and real-time translation functions, supports wireless charging, and has a 24h overall battery life.
52audio also disassembled Google Pixel Buds bluetooth headset, Google PH-1 USB-C interface wired headset. Let’s take a look at the detailed dismantling report of this product.
|1. Google Pixel Buds 2 Charging case teardown
The unique and stylish design of Google Pixel Buds 2 true wireless earphones has become a factor for many consumers to buy, but what about the internal structure configuration? Let’s go to the dismantling part to find out.
The charging case cockpit is fixed by glue, and the cockpit is pried open after heating.
Take out the cockpit, there is a flat cable connected to the small power input board at the bottom of the shell.
There is a metal cover plate above the small power input board for isolation from the battery.
Power input small board structure.
Take out the internal bracket, the front is an LED indicator, the black shielding cover prevents light leakage.
LED indicator and light guide.
On the back is the bluetooth pairing function button.
Type-C charging port at the bottom.
The charging interface is provided with a sponge pad, which plays a role of dustproof and waterproof sealing.
Graphene heat dissipation stickers are affixed to the shell.
The cockpit main board is reinforced by metal sheets, and at the same time plays a role in enhancing heat dissipation.
Metal sheet front.
The back of the metal sheet. Cover with yellow insulating coating.
The bottom power input cable is connected to the motherboard through the BTB connector.
Front components on the cockpit.
On the back of the cockpit is the wireless charging receiver coil.
The transmitting coil of the wireless charger generates a certain current in the receiving coil through the electromagnetic induction effect based on a certain frequency of alternating current, thereby transferring the electric energy from the transmitting end to the receiving end, and then powering the battery in the TWS charging case.
On the bottom is a lithium-ion soft pack battery, silk screen Sunwoda.
The battery cable is connected to the motherboard through the BTB.
The battery is fixed on the cockpit bracket by double-sided sponge stickers.
Polymer soft pack battery model G1013-B, rated voltage: 3.8V, rated capacity 555mAh/2.11Wh.
It can be seen on the back that the polymer soft pack battery comes from ATL.
The battery protection board, the protection IC is coated with a large amount of black hard glue, and the chip information cannot be obtained.
Circuit on the motherboard side.
Circuit on the other side of the motherboard.
The voltage regulator transistor of the silk screen KF0.
Silk screen 120A IC.
TI BQ51003 wireless receiver power supply, in line with WPC V1.2 standards, is optimized for 2.5W applications. The overall peak AC/DC conversion efficiency is 93%. It integrates a fully synchronous rectifier, a low-dropout regulator, digital control, and precise voltage and Current loop, used for earphone wireless charging and receiving.
The IC of silkscreen NN7001.
The Maxim MAX8971 single-cell lithium battery DC-DC charger can provide a charging current of 1.55A to the battery, the input voltage can reach 7.5V, and it can withstand transient voltages up to 22V. Support protection functions such as low-voltage warning, charging fault timer, die temperature and battery temperature monitoring, and support I2C control. Used to charge the built-in battery.
Silkscreen 7048 A6F51AA IC.
The IC of silk screen R.
The IC of the silk screen qc DS.
ST STM32L431RC6 MCU, used for the whole machine control function. Built-in Cortex-M4 core.
|2. Google Pixel Buds 2 earbuds teardown
Pry the earphone back panel along the parting line.
The main board unit is fixed in the back cover.
The earphone uses a steel shell button battery, which is fixed on a transparent bracket, and the battery is covered with shielding insulation stickers.
Take out the battery, the internal structure of the cavity.
Transparent bracket, fixed by buckle.
The internal components of the front cavity. The unit and sensor in the cavity are fixed and reinforced with hard glue.
After actual measurement, the size of the speaker unit is about 12mm.
Two microphone units are arranged on both sides of the cavity wall, one of which is used for noise reduction in calls to pick up external environmental noise.
The other one is used for voice call pickup.
Laser carving G367 MEMS microphone.
The 1240 steel shell button battery comes from VARTA, with a rated voltage of 3.7V and a rated capacity of 0.2W.
Pry open the motherboard, below is the touch sensor patch and bluetooth antenna.
The inner structure of the cover, the edge of which is printed with LDS laser antenna.
The circuit on the side of the main board unit.
The circuit on the other side of the main board unit.
Capacitive touch sensor for touch operation.
ST STM32L431RC6 single-chip microcomputer, used for headset auxiliary function control.
Screen printing 6BT battery protection IC.
Screen printing 9Y1 battery protection tube.
Silk screen + AAAA IC.
Silk screen DSP D8S1B IC.
Metal shrapnel used to connect the laser antenna.
ST LSM6DSL, high-performance 6-axis sensor, integrated acceleration and gyroscope, used for tap touch function.
According to 52audio, audio products from brands such as Apple, Amazon, Samsung, Huawei, Xiaomi, vivo, and Edifier all use ST sensors.
Silkscreen 7048 IC.
ST LIS25BATR high-bandwidth voice acceleration sensor is applied to the voice detection function and call noise reduction function of earphones. Compared with the traditional dual Mic solution, the bone vibration sensor has better suppression of wind noise/environmental noise.
The IC of silk screen 091.
TI BQ25150 linear charging IC adopts a standard lithium-ion charging curve to charge the battery in three stages: precharge, constant current and constant voltage regulation. It supports up to 500mA of charging current and supports as low as 0.5mA of termination current to achieve the best Fully charged.
BES BES2300 series bluetooth audio SoC is a fully integrated adaptive active noise reduction solution that supports bluetooth 5.0, IBRT intelligent forwarding technology and dual-mode bluetooth 4.2. It also supports the third-generation TWS full wireless stereo technology, dual microphones, etc. The BES2300 series has multiple versions and different configurations with different suffixes.
The BES2300 series also supports external sensor devices such as heart rate sensors, acceleration sensors and eMMC flash memory, which can achieve the purpose of playing music on external storage devices. BES2300 can output sound to headphones and home audio, and can also record from an external microphone.
According to 52audio, there are already a large number of true wireless headsets from Samsung, Xiaomi, OPPO, JBL, 1MORE, Honor, Baidu, OnePlus, Transsion, Realme, Anker and other brands that have adopted the BES solution.
All components of Google Pixel Buds 2 true wireless earbuds.
Google Pixel Buds 2 true wireless earphones are designed with an oval shape in the charging case, small in size, and easy to open and close with one hand in a vertical structure. The earphones are very distinctive, light and stylish in appearance, very decorative to wear, ergonomic design, and also provide a very comfortable wearing experience. The overall design is highly recognizable in the current TWS headset market.
In terms of internal circuits, the internal structure of the charging case is complex and orderly, supporting both wired and wireless input modes. The cable uses Type-C interface to input power, and the built-in battery is charged by the Maxim MAX8971 single-cell lithium battery DC-DC charger. The wireless uses TI BQ51003 wireless receiver, which complies with WPC V1.2 standard, and the overall peak AC/DC conversion efficiency reaches 93%. ST STM32L431RC6 MCU is used for the whole machine control function. Built-in 3.8V high-voltage battery with a capacity of 555mAh, from ATL, provides longer battery life.
Google Pixel Buds 2 earphone part, the internal structure layout is regular, the components in the front cavity are connected to the back cavity main board through the cable and the BTB connector. The headset uses a 12mm dynamic drive unit, dual MEMS microphones, dual optical in-ear detection sensors, and a 0.2Wh VARTA steel shell button battery is protected by a transparent bracket to improve safety.
On the motherboard, the main control chip uses BES2300 series bluetooth audio SoC, bluetooth 5.0, supports the third-generation TWS full wireless stereo technology, dual microphones, etc. TI BQ25150 linear charging IC supports up to 500mA of charging current and as low as 0.5mA of termination current to fully charge the built-in battery. ST STM32L431RC6 single-chip microcomputer, used for headset auxiliary function control. ST’s two acceleration sensors are used for touch and voice interaction functions.