PHILIPS is a large multinational company that has launched many home audio, headphones and wireless speaker products for the audio market. Bluetooth headsets cover various forms such as TWS true wireless earphones, head-mounted bluetooth headphones, neck-mounted bluetooth headphones, etc., each with its own distinctive design and rich functions.
With the popularity of noise-canceling headphones, Philips has also successively launched a number of products equipped with active noise-canceling functions. The one that 52audio will disassemble this time is PHILIPS TAH9505. This product is equipped with hybrid active noise reduction technology, supports active noise reduction function, and has an ambient sound mode; it adopts 40mm driver, bluetooth 5.0 technology, and has obtained Hi-Res high-resolution audio certification; physical buttons + touch operation mode, improve Convenience of interaction; battery life reached 27 hours.
Before 52audio teardown the Philips TAT2205, Philips SHB4385 and Philips TAT1285, this time let us take a look at the internal structure of this head-mounted noise-cancelling headphones!
| PHILIPS TAH9505 headphones teardown
Coming to the disassembly part, first remove the snap-fit earmuffs.
Inside the earmuffs, glue is fixed with a layer of dustproof cotton.
The noise-reducing microphone on the sound cavity cover is also covered with a sponge pad.
Back-feed noise reduction microphone, used for speaker output sound collection.
The front of the noise reduction microphone is covered with dustproof cotton.
Remove the screw to open the left ear cavity, which contains the battery unit.
The wire adapter board is fixed by screws, and the battery, the speaker, the noise reduction microphone and the wire extending from the right ear are welded. The wire is connected by welding through a small board, which is convenient for assembly.
The battery unit is fixed by a card slot and glue.
The feed-forward noise reduction microphone is located in a separate cavity, sealed with blue glue, and screwed on the wall of the earphone cavity.
Noise reduction microphone unit.
The other side of the noise reduction microphone unit is covered by a dust-proof net.
The back of the electret noise reduction microphone.
The front of the electret noise reduction microphone.
On the front of the adapter board, dozens of wires are soldered, and the solder joints are full and round.
The back of the adapter board is soldered through holes without any components.
Battery unit, lithium-ion soft pack battery model AEC653440, rated voltage: 4.2V, rated capacity: 900mAh; from AEC.
The battery protection board is responsible for the overcharge, overdischarge and overcurrent protection of the battery, and has the thermistor to detect the battery temperature.
The tuning hole of the sound cavity is covered by a fine dust-proof net inside and protected by a sponge cover outside.
Open the sound cavity and solder the wires to the speaker PCB board.
The back of the speaker, silk screen SY 201209 B1.
The front of the speaker.
According to the actual measurement by Woai Audio Network, the size of the speaker unit is about 40mm, which is consistent with the official publicity.
Coming to the right cavity, the structure of the sound cavity cover is the same as that on the left.
Right ear noise-canceling microphone.
Open the right ear cavity, connect the speaker wire via hole to the motherboard, and seal it with glue.
In the internal structure of the right ear cavity, the main board adapts to the sound cavity structure of the speaker unit, using an irregular crescent-shaped main board, and the inner side of the back board is covered with a PCB touch pad.
The motherboard and the touchpad are connected through a flat cable and a socket.
Indicator light guide.
The right ear feedforward noise reduction microphone has the same structure as the left ear.
Right ear feed-forward noise-canceling microphone.
Electret microphone for voice call function.
Take out the motherboard and touchpad.
Components on the front of the motherboard.
Components on the back of the motherboard.
The power button, ANC noise reduction switch, voice assistant button, and the three patch buttons on the motherboard are of the same specification.
Two LED indicators of different colors.
Type-C charging interface female socket.
2.5mm audio input interface female socket.
LPS LP5300 input overvoltage protection IC, the highest input withstand voltage up to 36V, to prevent input overvoltage from damaging the internal components of the headphone.
According to 52audio, TWS headset charging boxes of well-known brands such as Edifier, JLab, Xiaomi, Motorola, OPPO, QCY, Lenovo, Honor, etc. have adopted a large number of LPS power solutions.
LPS LP3980 3.3V low-noise ultra-high-speed linear regulator, with a maximum output current of 500mA, used to power other chips.
Details of LPS LP3980.
LPS LP28300A 2A Li-ion battery charger. A 500KHz synchronous buck converter topology is used to reduce power consumption during charging. Low power consumption, built-in MOS tube can reduce the volume of the charging circuit. The LP28300 includes a complete charge termination circuit, automatic charging.
Details of LPS LP28300A.
TI TPS62231 1.8V synchronous switch buck converter, which supplies power to the chip on the headset.
TI TPS62236 1.85V synchronous switch buck converter, which supplies power to the chip on the headset.
The IC of silk screen TBKP.
Two step-down inductors.
Onboard bluetooth antenna.
BES BES2300ZP main control chip, fully integrated adaptive active noise reduction solution, supports bluetooth 5.0, IBRT low-frequency forwarding technology and dual-mode bluetooth 4.2, it also supports the third generation of FWS full wireless stereo technology, dual microphones, etc., using 28nm HKMG CMOS process , BGA package. BES2300 supports high-performance adaptive active noise reduction technology, which allows high-end active noise reduction headphones to use a fully integrated chip to achieve high sound quality and active noise reduction.
In addition, BES2300 also supports external heart rate sensors, acceleration sensors and other external sensor devices 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 brands such as Huawei, Samsung, Xiaomi, OPPO, JBL, 1MORE, Honor, Baidu, and OnePlus that have adopted the BES solution.
A close-up of the 26.000MHz crystal oscillator, which provides a clock for the bluetooth chip.
ST STM32F031G6 has 32 KB flash memory, 48 MHz CPU, mainstream ARM Cortex-M0 access line MCU for motor control.
The STM32F031x4/x6 microcontroller integrates a high-performance ARM Cortex-M032-bit RISC core that runs at a frequency of up to 48 MHz, high-speed embedded memory (up to 32 KB of flash memory and 4 KB of SRAM), and a wide range of enhanced Peripherals and I/O. All devices provide standard communication interfaces (one I2C, one SPI/I2S and one USART), one 12-bit ADC, up to five general-purpose 16-bit timers, one 32-bit timer and one advanced control PWM timer.
SGMICRO SGM4564 four-channel level conversion communication IC, used for chip communication under different power supply voltages.
Silk screen 11.289MHz crystal oscillator.
YAMAHA YMU831 digital noise reduction IC, built-in DSP digital signal processing technology. Call/music processing IC for mobile terminals, with dual microphone noise reduction for calls, active noise reduction for earphones, enhancing the call experience, unique Yamaha professional DSP, optimizing music processing.
fortemedia FL123CE, microphone ADC conversion chip, supports analog microphone array, converts analog sound signals into digital signals and sends them to YMU831 for noise reduction processing.
RUNIC RS550 is a high performance 4PST (4 Pole Single Throw) normally closed depletion mode isolation switch. The depletion mode technology allows the device to conduct signals when no VCC is available, and isolate the signals when VCC is present. The main application scenario is audio systems such as noise reduction headphones.
RUNIC RS550 detailed information.
The IC of silk screen TBKP.
Silk screen 4R7 inductor.
The TVS with silk screen 7A is used for input overvoltage protection. The TVS below the picture is also used for overvoltage protection of the data pin.
The front of the circular touchpad.
The back of the round trackpad.
The touch IC of the silk screen CST812S is used to detect the touch operation of the headset.
The cable socket for connecting the touchpad to the motherboard.
The internal structure of the function keys.
The pressure relief hole in the right ear cavity is covered by an internal dust-proof net to ensure air circulation in the cavity.
All components of PHILIPS TAH9505 head-mounted noise-cancelling headphones.
PHILIPS TAH9505 head-mounted noise-cancelling headphones adopt a ring-shaped connection structure on the appearance of the head beam and ear shell. The ear shells and ear cups are also circular in design. With the integrated design of the head beam, the overall look is very simple and stylish. And has a strong integration. The ear shell supports four-way rotation up, down, left, and right, with a telescopic structure to adjust the size to improve personalized wearing comfort.
In terms of internal structural configuration, in addition to the speaker unit, there are a battery unit and two noise-reducing microphones in the left earphone, which are connected to the right earphone through a wire adapter board. The battery capacity is 900mAh, equipped with circuit protection, from AEC. The right earphone has a motherboard unit and a touchpad, which are connected through a cable and a connector, and three microphones, two for active noise reduction and one for voice calls.
On the motherboard, the main control chip uses BES BES2300ZP bluetooth audio SOC, fully integrated adaptive active noise reduction scheme, supports bluetooth 5.0, supports the third generation of FWS full wireless stereo technology, dual microphones, etc.; YAMAHA YMU831 digital noise reduction IC, built-in DSP Digital signal processing technology, with dual microphone noise reduction for calls, and active earphone noise reduction. Equipped with fortemedia FL123CE, microphone ADC conversion chip, which converts analog sound signals into digital signals and sends them to YMU831 for noise reduction processing.
ST STM32F031G6 microcontroller is used for reset, power supply, clock management and other functions; SGMICRO SGM4564 four-channel level conversion communication IC for chip communication under different supply voltages; LPS LP5300 input overvoltage protection IC, LP3980 3.3V low Noise ultra-high-speed linear regulator, LP28300A 2A lithium-ion battery charger; RUNIC RS550 isolation switch; TI TPS62231 1.8V synchronous switch buck converter, TPS62236 1.85V synchronous switch buck converter, etc.