With the release of Apple‘s first-generation AirPods true wireless earphones, it has led to the rapid rise of the TWS earbuds market. The entire industry chain has been greatly improved from appearance design to battery, charging, and chip solutions.
Subsequently, Apple has successively released multiple generations of products such as AirPods 2, AirPods Pro and AirPods 3. The product performance has been gradually improved, and the functions have been continuously enriched, which is deeply recognized by consumers. Apple products continue to top the list of TWS earbuds.
After three years, Apple AirPods Pro 2 finally arrived as scheduled at Apple’s autumn conference. The appearance continues the simple design style of Apple AirPods Pro, and the configuration adopts the newly upgraded H2 chip, which supports Bluetooth 5.3. The ability of active noise cancellation has been greatly enhanced, and an adaptive transparency mode has been added, which can suppress high-volume noise in the environment and reduce more external noise. Secondly, the charging case has a built-in U1 chip, which supports the personalized spatial audio technology of precise positioning and dynamic head tracking, bringing a personalized and immersive audio experience.
At the same time, earphones and charging case are equipped with IPX4 sweat and water resistance. In terms of battery life, when ANC is turned on, a single battery life can reach 6 hours, which is 33% higher than that of Apple AirPods Pro. The comprehensive battery life is up to 30 hours, which is 6 hours more than AirPods Pro. Apple has also added support for charging with Apple Watch chargers and MagSafe chargers, and has optimized touch operations for easy manipulation of playback functions on the headset stem.
01/ Apple AirPods Pro 2 charging case teardown
We separate the lower part of the charging case. It can be seen that the lower shell and the middle frame are connected by two cables, and the cables are respectively connected to the lightning interface and the wireless charging coil.
Internal structure of charging case.
The lightning port inside the lower casing is wrapped by a metal casing fixing and fixed with screws.
The cable of the lower shell is connected with the main board of the upper shell through the cable socket, and the soft glue is reinforced.
The button FPC on the inner side of the lower casing and the wireless charging coil. The charging coil is attached to the inner wall with hard glue, which is difficult to disassemble and the structure is irreversible.
Magnet for MagSafe wireless charging.
Indicator light on the other side inside the lower housing.
The upper casing structure is shown on one side.
The upper casing structure is shown on the other side.
The middle frame approximates a sandwich structure. The charging case is equipped with two upper and lower batteries, and the motherboard is in the middle of the two batteries, making full use of the internal space.
The wireless charging coil is fixed inside the case by glue.
The screw next to the metal case holder that wraps the Lightning port.
The charging case pairing buttons.
Metal brackets that hold the speaker.
Balance air hole position, attached with metal mesh and a layer of milky glue.
Structural fixing brackets. It integrates the functions of lanyard hole, speaker fixing ring and charging interface fixing ring.
The structural fixing bracket is shown on the other side.
Gasket inside the button hole.
The edge of the motherboard is welded with a metal sheet, which is in contact with the socket shrapnel and grounded.
Schematic diagram of the shrapnel connected to the female seat.
Charging case speaker.
Separate the internal structure of the charging compartment.
The bottom structure of the charging cabin covers a large area with graphene heat dissipation stickers.
Magnets inside the charging compartment.
The internal structure of the charging compartment.
A magnet for attaching earphones.
Hall element, used to detect the opening and closing status of the charging case.
Magnets on both sides of the charging cockpit bracket.
The overall structure is displayed on one side.
The overall structure is shown on the other side.
A shield with a QR code printed on it.
Separate all components in the charging case.
The cable on the back of the earphone cockpit.
The cable solder joints are reinforced with glue.
A BTB cable interface is connected below the Hall element.
Remove the metal protective cover.
Hall structure display.
FPC cable structure.
Speaker for making sound.
A QR code is printed on the T-iron on the back of the speaker.
The wireless charging coil is connected to the motherboard through the FPC cable.
The micro switch for the pairing key of the charging case.
Thermal protection device from Bourns for wireless charging coil temperature detection.
Wireless charging receiver circuit.
BROADCOM 59356A2KUBG wireless charging management IC in BGA package.
Silkscreen 5LJ IC.
The battery packs are connected by cables.
A metal shield is soldered to the back of the battery connector.
Below the shield is a glued and sealed element.
Rechargeable Li-polymer Battery Information: Model A2798, Made in China, Charging Limit Voltage: 4.35 Vdc, Nominal Voltage: 3.82Vdc, Rated Capacity: 523mAh (PS: Total capacity of two Li-polymer batteries in parallel), from Sunwoda electronic.
The lithium polymer battery has an independent protection circuit, and there are two batteries, each with a protection circuit. The IC on the protection board is also covered with a translucent hard glue.
Built-in motherboard circuit structure.
The circuit structure on the other side of the built-in motherboard.
The bluetooth antenna on one end of the motherboard of the charging case.
Bluetooth antenna on the other side.
NORDIC NRF52832, multi-protocol Bluetooth 5, ANT/ANT+ and 2.4G private protocol wireless RF SoC chip, supports NFC function. Built-in 64MHz Cortex-M4F processor core, using WLCSP3.0*3.2mm package, the peripheral components are simplified.
A chip with a QR code on the surface, silkscreen 2ZRT, and Apple’s custom ultra-wideband chip. According to 52audio, it has been widely used in Apple iPhone and HomePod Mini smart speakers, and is an important part of Apple’s future product ecosystem.
The ultra-wideband chip has the characteristics of strong anti-interference ability and high positioning accuracy, and the transmission distance is about 10 meters. The US FCC (Federal Communications Commission) has allocated the 3.1GHz~10.6GHz frequency band for UWB, and occupying such a large bandwidth is also one of the reasons why some countries and regions have banned UWB technology.
An Apple custom chip, silkscreen 343S00562.
ST STM32L496WGY6P ultra-low power Arm Cortex-M4 32-bit MCU+FPU.
Silkscreen FMM IC.
Silkscreen C1IUE IC.
Silkscreen AKN’s IC, from Maxim, model MAX98357B, is a Class D audio amplifier used to drive the voice coil to sound. According to 52audio, its function in this charging case is to play the sound to find the location.
NXP 610A3B USB charging IC.
Silkscreen memory IC of E8ELW.
Silkscreen 2878 IC.
Silkscreen 8L22B7 and 451C ICs.
Silkscreen 22F208 IC.
An overview of the internal material structure of the Apple AirPods Pro 2 charging case.
02/ Apple AirPods Pro 2 earphones teardown
In the teardown part of the earphone part, 52audio teardown earphones as much as possible without damage and recovery. First disassemble along the center line of the earphone.
The cables of the Apple H2 SIP System in Package are connected to the speakers and battery units of the head cover through sockets.
The earphone is assembled from three parts: earphone head, headset stem, and bottom cover.
According to 52audio, this is a special-shaped iron block that is not small in size. It is magnetically fixed with the charging case magnet, and the center of gravity of the earphone is adjusted so that the center of gravity will not be too far out or too far inward. It acts as a counterweight to make the earphone stay in the ear more stably.
The earphone shaped metal block.
Remove the H2 system package (System in Package) cable, and separate the earphone head cover. The inside of the head cover includes the battery, earphone unit, feedback microphone and other sensor components.
Remove the battery unit.
The coin cell battery is from Samsung SDI, model number A2731. The rated capacity is 49.7mAh/0.182Wh, and the rated voltage is 3.66V.
The contact surface of one end of the FPC cable in the earphone cavity.
Internal structure of earphone cavity.
Separate the protective bracket inside the earphone cavity.
The button battery in the earphone cavity is wrapped around the FPC cable.
A fixed metal shield located inside the sound mouth of the earphone cavity.
The FPC cable is fixed inside the cavity bracket.
Then remove the speaker unit.
The FPC cables are arranged in a surrounding arrangement inside the earphone cavity, and the infrared distance sensor is fixed inside the earphone shell.
Infrared distance sensor inside earphone for wear detection function.
The sensor is windowed and uses black plastic to block visible light.
A metal protective frame is set around the noise cancellation microphone.
The bent iron wire is used to fix the earphone silicone eartips, and at the same time, it plays the role of fixing the noise cancellation microphone.
Plastic bumps on both sides to hold the dimples inside the silicone eartips.
A metal protective cover is arranged above the noise cancellation microphone.
The front of the speaker unit is a black diaphragm.
The back of the speaker unit.
After actual measurement, the diameter of the AirPods Pro 2 earphone speaker unit is about 11mm.
Tuning holes around the speaker unit.
The earphone’s built-in battery and speakers are soldered to the cable.
The H2 packaged system chip inside the earphone.
Pick apart the coaxial antenna connector.
Apple H2 System in Package front.
Coaxial antenna connection plug.
The cable is fixed with glue.
A whole cable runs through the entire inner wall of the headphone holder.
Bottom pickup microphone.
A touch sensor is arranged on the side of the internal components of the back panel and below.
Backplane internal components back. This is earphone’s separate bluetooth antenna.
Touch the structure on the other side of the IC.
Metal contact surface with protective foam placed under it.
Below the touch sensor is an IC with a silkscreen QR code.
Remove the touch sensor.
Laser carving S 289 noise cancellation microphone.
A chip is also soldered on the sensor cable.
Back of Apple H2 System in Package.
The acceleration sensor cooperates with the optical sensor to detect the wearing state of the user. On the right is the Bluetooth antenna socket.
All components of Apple AirPods Pro 2 true wireless noise cancellation earphones.
Apple AirPods Pro 2 inherits Apple’s consistent design style in appearance. The pure white integrated design is very simple and has a very overall sense. The earphones have a short handle in-ear design, and the headset stem and earphone cavity are integrally formed and feel smooth. The openings and sensor positions on the earphones have been adjusted, adding XS size eartips. The charging case adopts an oval shape with a simple design, and the openings are all functional openings. Such as the newly added lanyard hole and the bottom speaker hole.
AirPods Pro 2 takes a whole new way of interacting. Volume adjustment is achieved by touching the built-in touch-sensitive sensor and sliding the grooved area of the headset stem. The overall design and manufacturing level of earphones is still high. The internal components are neat and orderly, the component materials are high-quality, the production process is excellent, and the sealing performance is good.
The earphones use the Apple H2 chip SIP package, with an acceleration sensor, and an optical sensor to detect the user’s wearing state to achieve head tracking. Using Apple’s custom 11mm high-amplitude dynamic driver, covering the black diaphragm. A single earphone has 3 built-in MEMS microphones for adaptive equalization, voice calls and other functions. The earphone uses a Samsung SDI model A2731 button battery with a capacity of 49.7mAh.
We learned that the internal components of the AirPods Pro 2 charging case use a structural fixing bracket, which integrates the functions of a lanyard hole, a speaker fixing ring, and a charging interface fixing ring. The wireless charging coil is pasted on the back of the charging case. There is a built-in NORDIC NRF52832, which supports Bluetooth low energy consumption, ANT/ANT+ protocol, 2.4G private protocol and NFC, etc., to realize long-distance positioning of charging case and information reading after loss. On this basis, AirPods Pro 2 is also equipped with Apple’s self-developed ultra-wideband chip for near-field direction and distance positioning. The combination of Bluetooth and UWB precise positioning technologies can help users find charging cases. The built-in lithium battery capacity of the charging case is 523mAh, which is from Sunwoda Electronics. The wireless charging solution adopts Broadcom 59356A2KUBG wireless charging management IC, and the wired charging adopts NXP 610A3B USB charging IC. ST L496WGY6P ultra-low power MCU+FPU.
Comparing AirPods Pro, the same thing is that both are equipped with outward-facing microphones (beam-forming microphones), inward-facing microphones and call microphones (beam-forming microphones). Outward-facing microphones are so-called feed-forward microphones that pick up ambient noise. Inward-facing microphones are so-called feedback microphones, which are optimized by detecting listening. The two are combined with the high-integration, high-performance H2 packaging system with real-time detection output, and the ultimate noise cancellation effect is achieved.
At the same time, AirPods Pro 2 adopts a short headset stem in-ear design and is integrated with the earphone cavity. The battery uses a button lithium battery, and the charging case uses two batteries in parallel, both of which support wireless charging. The package includes eartips and a USB-C to Lightning cable.
The difference is that the AirPods Pro 2 has a new upgraded H2 chip that supports Bluetooth 5.3. Cooperate with custom speaker drivers and amplifiers to reduce distortion and greatly improve sound quality. The newly designed inward-facing microphone and the voice enhancement algorithm make the recognition and sound transmission more natural, and the tuning achieves more delicate and rich sound quality. ANC mode is added, and the official claim that the noise cancellation effect is doubled compared to the previous generation. Optimize the position of the noise cancellation microphone and the rear air vent inside the earphone to quickly detect the in-ear sound and quickly cancel it. Added XS eartips, built-in U1 chip in charging case and built-in speaker and lanyard hole. In addition, when the battery capacity is almost the same as that of the previous generation, with the lower power consumption of the H2 chip, the overall battery life of AirPods Pro 2 has increased by about 6 hours compared with the previous generation.