Google Pixel Buds is the first generation of bluetooth earphones launched by Google. Its charging case is wrapped in fabric material. There is a lanyard connection between the left and right earphones, and there is a wire inside to transmit audio signals. The earphones look like an in-ear design, but they are The state of semi in-ear is a more distinctive product.
Google Pixel Buds have built-in 40 languages and can perform 1-to-1 real-time translation; the headset supports touch operation, long press the headset to wake up the Google Assistant and achieve voice interaction with the phone; the headset also supports swiping forwards and backwards to adjust the volume , And click pause/play, double click to switch to the next song. Pixel Buds has a battery life of 5 hours per use, and a total battery life of about 24 hours with the charging case. The listing price of this product that year was $159. To
52audio has disassembled Google PH-1 wired earphones before. The appearance design of Pixel Buds earphones continues the style of this product. Let’s take a look at the detailed dismantling.
| 1. Google Pixel Buds appearance display
The charging case has a square appearance, and the surface is a layer of fabric texture material, which is more resistant to dirt and non-slip.
There is a Google letter “G” Logo in the middle of the lid.
The USB Type-C charging interface is on the back of the fuselage, and there is a protective part on the outer ring to avoid damage to the housing by plugging and unplugging the charging cable.
Use a portable power tester to perform a wired charging test on Google Pixel Buds bluetooth headphones. The charging power is about 2.3W.
The internal layout of the charging case is shown, the earphone is magnetically attracted in the groove, and the lanyard can be wound on the shell.
The magnet that attracts the lid of the box is painted black to make it more concealed.
The groove for fixing the earphone has charging contacts inside. The earphone is adsorbed by a magnet, and the L/R left and right logos are printed on the magnet.
There is a sticker inside the lid to show how the lanyard is wound.
The quick pairing button on the charging cockpit shell.
Hidden indicator light design in the charging cockpit shell.
The headset and charging case weigh a total of 58.4g.
The individual weight of the charging case is 44.7g.
The left and right earphones and lanyard weigh 13.6g.
Google Pixel Buds bluetooth earphones.
| 2. Google Pixel Buds charging case teardown
Pry open the charging cockpit, the side is fixed by multiple physical buckles.
The internal structure of the charging case is shown. The battery is at the bottom, and there is a circle of foam buffer at the contact position of the case; the motherboard is fixed with multiple screws.
A plastic part is fixed at the charging interface to improve the stability of the plugging and unplugging of the charging cable.
The charging cockpit shell after taking out the main board circuit. The upper left corner is the shell of the button, and the upper right corner is the light guide plate of the indicator light.
One side of charging case internal circuit.
Charging case The other side of the internal circuit.
The Pogo Pin for charging the headset is on a separate PCB and is connected to the motherboard through the FPC and connector.
A close-up of the gold-plated Pogo Pin charging the earphones, with dust and waterproof rubber rings.
The built-in soft pack battery comes from ATL, model 632235, with a rated voltage of 3.8V and an energy of 2.39Wh.
Battery protection board.
The battery is fixed on the motherboard with double-sided tape. Remove the battery and see that there is no IC on the back of the motherboard.
Circuit on the other side of the motherboard.
The USB Type-C charging interface is soldered to the motherboard via a through hole, with a dustproof and waterproof rubber ring.
TI (Texas Instruments) BQ24392 USB2.0 switch, with charger detection function, supports overvoltage protection.
Active-Semi (acquired by Qorvo) ACT2801 mobile power solution for charging case battery charging and headset charging.
Details of ACT2801.
TI TPS70618 6.5V input linear regulator, output voltage 1.8V.
The MOS tube of silk-screened PDUS is used for power supply switching.
Cypress CY8C4146FNI-S433 PSoC, built-in ARM Cortex-M0 core, used for charging case internal control function.
Cypress CY8C4146 detailed information.
TI LP55231 9 output LED driver with built-in charge pump.
A Hall element on the top of the circuit board.
TLV431 and a triode provide power for the Hall element.
Multiple LED indicators, outer ring foam to avoid light leakage from the shell.
SMD jog button.
| 3. Google Pixel Buds earphones teardown
Let’s continue to disassemble the earphone part of Google Pixel Buds. There is a lanyard between the left and right earphones (in fact, it is also a data cable). If there is no charging case, there is no need to worry about the earphones being out of place.
Plastic parts used to adjust the length of the lanyard.
As shown in the figure, the length of the part where the lanyard passes through the earphone can be adjusted, and it can be adjusted according to the auricle when wearing it, which has a better fixing effect. The design is very clever.
The earphone shell is round and engraved with Google’s letter “G” Logo.
An opening is provided where the lanyard passes through the earphone shell.
The pickup hole of the call microphone.
The charging contacts on the inner shell of the earphone.
The circular pressure relief/tuning hole on the shell is printed with L/R logo.
The dust-proof net at the position of the sound mouth prevents foreign objects from entering.
The pickup hole of another call microphone.
The cover can be removed to heat the earphone shell. A headset is a motherboard circuit, and a headset is a button battery.
One side of button battery.
One side of the motherboard circuit.
Let’s take a look at the internal structure on the side of the battery.
The label information on the side of the battery is a rechargeable lithium-ion battery with a capacity of 120mAh and an energy of 0.44Wh.
The battery model is 318000800522, assembled in China.
The positive and negative nickel sheets of the battery are welded to a PCB with multiple wires underneath, and the solder joints are reinforced with glue.
Lithium battery protection IC of silk screen 5Z 7IC.
The size comparison of button battery and RMB coin.
The button battery comes from VARTA, model CP1654A3, with a diameter of 16mm, a height of 5.4mm, a rated voltage of 3.7V, and an energy of 0.4Wh.
According to 52audio, many world-renowned brands, including Apple, Samsung, Sony, BOSE, B&O, Microsoft, Amazon, and Jlab, have adopted VARTA button batteries in large numbers.
The other side of the PCB.
The internal structure of the cavity is displayed. The speaker unit is an independent structure and will be disassembled below.
The shell of the other earphone, the middle area is the touch pad, and the outside is the LDS bluetooth antenna.
The internal structure of the headset is displayed.
Comparison of the size of the headset motherboard and RMB coin.
The circuit on the motherboard side is displayed, and the internal circuit is connected through the FPC and the connector.
Circuit on the other side of the motherboard.
Qualcomm CSR8675 supports bluetooth V5.0 and includes an upgraded digital signal processor core. Compared with the previous generation of 80MIPS DSP, its processing performance is as high as 120MIPS. Therefore, the new Qualcomm CSR8675 can support advanced audio processing algorithms to provide superior audio processing algorithms. High-quality enhanced audio performance. In addition, SoC supports 24bit digital audio. This high-performance core enables devices based on the CSR8675 platform to output high-definition audio, which is a classic product of the generation.
According to 52audio, well-known brands such as Anker, Bose, Beyerdynamic, B&O, Cleer, Edifier, Xiaomi, Microsoft, OPPO, vivo, Sony, and 1More have adopted Qualcomm’s bluetooth audio SoC in large numbers.
The external storage of the silk screen 6340D U64M is used to store bluetooth configuration information and so on.
Maxim MAX8971G switch charging IC, used to charge the built-in battery of the headset, supports a single-cell lithium battery, and supports I2C control.
Maxim MAX8971G details.
TI TPS62743 ultra-low power consumption synchronous rectification step-down converter, used for battery step-down to power the internal chip of the headset.
TI BQ27421 fuel gauge chip, built-in current detection resistor, used to monitor battery power.
An acceleration sensor is used for the tap control function of the headset.
Silkscreen 202 201 IC.
Silkscreen 3324T 1737 IC.
Cypress CY8C4146FNI-S433 PSoC, used for touch detection and in-ear detection functions.
Connect the Pogo Pin of the bluetooth antenna.
The internal structure after removing the motherboard.
There is a fixed baffle at the call microphone position.
After removing the baffle, you can see the microphone, and there is a cushion foam at the contact position of the baffle.
Laser carving S1902 8000 MEMS silicon microphone.
At the location of the other silicon microphone, the two microphones are placed opposite each other.
Disassemble the independent cavity of the speaker unit.
The plastic part for fixing the speaker unit.
The pressure relief hole of the front cavity, and the FPC for ear detection is on the inside of the side shell.
One side of the Dynamic driver diaphragm.
Code information on the Dynamic driver magnet, MP1120B.
The speaker unit is about 12.7mm in diameter.
All components of Google Pixel Buds bluetooth headset.
Google Pixel Buds is the first generation of bluetooth headsets launched by Google. There is a wired connection between the left and right earphones. One side is a bluetooth chip and one side is a battery. They are not true wireless earphones. The earphones look like an in-ear design, but they are semi-in when worn. -In the state of ear, the lanyard can be adjusted in length and used as ear flaps for easy wearing, or hung on the neck; the Charging case is wrapped in fabric material, the buttons and indicators on the inside are hidden design, and the structure design is also convenient for earphone placement. It is a very distinctive product.
In terms of internal circuits, the charging case inputs power through the USB Type-C interface. TI BQ24392 has a charger detection function and supports over-voltage protection. The ACT2801 power management chip is responsible for stepping down the charging case battery and boosting the headset for charging; soft pack battery From ATL, the energy is 2.39Wh; Cypress CY8C4146FNI-S433 PSoC is responsible for the overall control of the charging case; TI LP55231 is used to drive the LED indicator, and there are Hall elements for opening and connecting function.
In the earphone part, Google Pixel Buds uses the Qualcomm CSR8675 bluetooth master chip, supports bluetooth V5.0, supports 24bit digital audio, is a generation of classic products, transmits bluetooth signals through the LDS antenna; Maxim MAX8971G switch charging IC is used to charge the built-in battery, TI TPS62743 is used to step-down battery output to power the internal chip of the headset. The button battery comes from VARTA with a capacity of 120mAh; the headset has a built-in 12.7mm dynamic speaker, which supports two interactive methods of tapping and touch. It has an in-ear detection function, where tapping The control is realized by the acceleration sensor, and the touch and ear detection adopt the capacitive solution. The control chip is Cypress CY8C4146FNI-S433; the headset has two built-in silicon microphones for call pickup; the overall design is unique and the materials used are good.