The realme brand was established in May 2018, focusing on the production of smartphones and IoT products. With its “dare to leapfrog” brand attitude and cost-effective products, it has attracted many young consumer groups. Previously, 52audio teardowned the realme Buds Q true wireless bluetooth earbuds, and the unique cobblestone design of the headset left a deep impression on us at the time. When the realme Buds Q2 true wireless earphones were released, 52audio had already paid attention to this product.
Recently, 52audio got the realme Buds Q2 true wireless earphones and teardowned them. In appearance, the compact and lightweight design of realme Buds Q is continued, with black and light blue colors. The functional configuration is equipped with a 10mm bass dynamic driver, supports DBB enhancement technology, supports high-definition call noise cancelling, low-latency game mode, and has a 20-hour battery life. Let’s take a look at the teardown report.
$21 – Check last price on: AliExpress, Amazon US, Amazon Germany, other Amazon countries
|1. realme Buds Q2 charging case teardown
After seeing the unpacking of the previous product, I believe that my friends already have an impression of the appearance of the realme Buds Q2 true wireless earphones. Next, we will enter the teardown link. First, let’s take a look at the internal power management system of the teardown charging case.
First, pry open the earphone cockpit along the parting line to separate the earphone cockpit and charging case.
The bottom case of the charging case is assembled with the earphone cockpit through snaps.
The battery is attached to the back of the mainboard of the charging case, and the mainboard is fixed to the back of the earphone cockpit by screws.
Screws that secure the motherboard.
Unscrew the screw to separate the charging case motherboard and the earphone cockpit.
At the bottom of the headphone cockpit, there are two magnets for attaching the earphone.
There is a magnet at the bottom of the two earphone cockpits for adsorbing earphones, and the magnets are fixed with glue.
The light guide structure at the position of the indicator light of the charging case prevents light leakage.
Remove the battery, the battery is fixed on the bottom of the motherboard with foam glue, and connected to the motherboard through wires.
The front of the charging case motherboard.
The back of the charging case motherboard.
The charging case battery is from ZWD, model ZWD802028, the rated battery capacity is 400mAh/1.480Wh, the rated voltage is 4.2V, and the rated working voltage is 3.7V.
Screen-printed BZ’s TVS diode for power input protection.
The LPS LP5305 overvoltage and overcurrent protection IC is used to protect low voltage systems from abnormally high input voltages. During operation, the IC continuously checks the input voltage, input current and battery voltage. When the protection state occurs, the power MOS will be turned off at the same time.
The LP5305 is a safety device that ensures accident prevention. If the input voltage exceeds the OVP threshold voltage level, the power MOS will turn off within 1μs. The current limit is adjustable with an external resistor between ISET and GND. And the current is also limited to prevent the battery from charging too much current. The LP5305 also monitors the Li-Ion battery voltage, when the battery voltage exceeds 4.35V, the IC will turn off the MOS. Additional features include overtemperature protection and undervoltage lockout (UVLO). The LP5305 is available in a space saving DFN-8 package.
According to 52audio, a large number of audio products from Xiaomi, OPPO, Huawei, Lenovo, Motorola, realme, Edifier, QCY, JLab, Skullcandy, Boltune and other brands have adopted the LPS power management solution.
The LPS LP28055 is a complete constant current/constant voltage linear charger for single-cell Li-ion batteries. The LP28055 is available in an ESOP8 package with low external component count, making it ideal for portable applications. Due to the internal MOSFET architecture, no external sense resistor and no blocking diode are required.
The LP28055 features thermal feedback regulation that adjusts the charge current to limit the die temperature during high power operation or high ambient temperature. The charge voltage is fixed at 4.2V, and the charge current can be set externally to ISET with a single resistor. After reaching the final float voltage, the LP28055 automatically terminates the charge cycle when the charge current drops to 1/10 of the set current value.
When input power is removed, the LP28055 automatically enters a low current state, reducing battery drain current to less than 1µA. Other features include a charge current monitor, undervoltage lockout, automatic recharge, and a status pin to indicate charge termination and presence of input voltage.
According to 52audio, a large number of audio products from Xiaomi, OPPO, Huawei, Lenovo, Motorola, realme, Edifier, QCY, JLab, Skullcandy, Boltune and other brands have adopted the LPS power management solution.
The LPS LP6260 ultra-low static current synchronous boost converter is used to boost the built-in battery in the charging case to charge the earphones.
The LP6260 has a TRUE true shutdown function, which can disconnect the input and output under shutdown and output short-circuit conditions, and the 1.2MHZ switching frequency can use small inductors and capacitors. The switch pin adopts a high-voltage 9V process, which can effectively absorb the high-voltage peak of the production capacity when the earphone is unplugged and plugged. At the same time, the LP6260 has no whistling sound within the range of full load capacity (especially light load).
The LP6260 consumes only 1UA of quiescent current under light load conditions, achieves up to 75% efficiency under 20uA load, and up to 93% conversion efficiency from 3.3V to 5V under 200mA load.
According to 52audio, a large number of audio products from Xiaomi, OPPO, Huawei, Lenovo, Motorola, realme, Edifier, QCY, JLab, Skullcandy, Boltune and other brands have adopted the LPS power management solution.
Small volume boost inductor.
8205 NMOS tube.
Silkscreen AZ2 025 lithium battery protection IC.
Pogo pin connector for charging earphone.
|2. realme Buds Q2 earbuds teardown
After reading the realme Buds Q2 charging case, let’s take a look at the internal structure of the realme Buds Q2 earbuds.
Remove the earphone back cover along the mold line, and install the main board on the earphone back cover.
The soft pack battery is installed in the front cavity of the earphone.
The soft pack battery is connected to the ZIF connector on the motherboard through the FPC cable.
Remove the earphone motherboard from the rear cover.
There is a capacitive touch patch in the back cover of the earphone, which is used to realize the touch function of the earphone. On the outer ring of the touch detection patch is the earphone’s bluetooth antenna, which is connected through the metal contacts on the motherboard.
The front circuit of the earphone motherboard.
The circuit on the back of the earphone motherboard.
The patch for earphone in-ear monitoring is used for earphone wearing detection, and realizes the function of putting on earphone to play songs and taking off the pause function.
BES WT230 supports Bluetooth 5.0 dual-mode, integrates high-performance Cortex-M4F core audio and voice application SoC, integrates high-performance audio decoder and headphone output without DC blocking capacitor, built-in Flash and MCU can support product personalized settings.
According to 52audio, the BES2500 series has been adopted by many products of Xiaomi, Samsung, OPPO, Honor and other brands. BES’ bluetooth audio solution has been widely adopted by true wireless earbuds of Samsung, Xiaomi, OPPO, JBL, 1MORE, Honor, Baidu, OnePlus, Transsion and other brands.
Laser carving R101 ADWD’s MEMS microphone for voice pickup.
The 26.000MHZ crystal oscillator provides the clock for the bluetooth chip.
LONGWECHIP LW8661S single-button touch detection chip. Low power consumption, fast response, strong power supply noise suppression and high consistency.
LWS661S has a built-in tax voltage circuit to provide stable voltage for the touch sensing circuit, and the stable touch detection effect can widely meet the needs of different applications. This touch detection chip is specially designed to replace traditional buttons, and the size of the touch detection PAD can be designed within a reasonable range according to different sensitivities. Low power torr and working voltage are the characteristics of this touch chip for DC or AC applications.
According to 52audio, there are still Soundcore LIFE A2 NC+ and omthing AirFree earbuds that use LONGWECHIP’s touch detection chip.
SINOMUC MC9934 8-bit microcontroller is used to trigger reset to transmit bluetooth signal again when the connection of bluetooth earphone fails to ensure that bluetooth does not crash. At the same time, it has ultra-low standby power consumption, extending the battery life of bluetooth headphones.
MC9934 adopts DFN8 package, has 8-bit CPU core, 1K×14-bit OTP type program memory and 50-byte SRAM general-purpose data memory. Built-in high and low frequency RC oscillators are used as the clock source for the system at high or low frequencies. It has two working modes: run mode and sleep mode. There are also self-oscillating watchdog counters and timers inside.
Hypower HP4554high input voltage charger with overvoltage protection, input withstand voltage 24V, 6.8V overvoltage protection, programmable charging current and termination charging current, used for earphone built-in battery charging.
Connect the metal dome on the touch area of the earphone cover.
earphone soft pack battery, from ZWD, model 541112, rated battery capacity 0.15Wh.
Then let’s take a look at the layout of the earphone cavity. The components inside the cavity are fixed by glue. Inside the earphone cavity, the right side is the magnet that adsorbs the charging case, the left side is the speaker unit, and the middle of the magnet and the speaker is the small board where the charging contacts are located, both of which are connected to the main board by wires.
Take out the circuit inside the earphone cavity.
Internal structure of earphone cavity.
Earphone circuit.
The front of the dynamic driver has a metal protective case.
The back of the dynamic driver.
Two charging metal contacts on the earphone circuit are used to charge the earphones.
After actual measurement, the dynamic unit size of realme Buds Q2 earbuds is about 10.07mm.
All components of realme Buds Q2 true wireless earphones.
|3. Summary
In terms of appearance, the realme Buds Q2 true wireless earbuds continue the compact and lightweight design of the realme Buds Q. The back of earbuds adopts the “kaleidoscope” dazzling film technology, presenting a unique visual perception. The charging case still adopts a pebble-like design, which is simple and stylish. The charging case battery is from ZWD, model ZWD802028, the rated battery capacity is 400mAh/1.480Wh, the rated voltage is 4.2v, and the rated working voltage is 3.7v.
In the dismantling of the charging case, we found that the mainboard of the charging case uses 3 LPS power ICs. They are: LPS LP5305 over-voltage and over-current protection IC, which can realize over-temperature protection and under-voltage lockout. The LPS LP28055’s 1A Li-ion battery linear charging IC features thermal feedback regulation that adjusts the charging current to limit chip temperature during high power operation or high ambient temperature. The LPS LP6260 is a synchronous boost converter with ultra-low quiescent current and shutdown that disconnects the input and output during shutdown and output short-circuit conditions. The LP6260 consumes only 1uA of quiescent current at light load conditions and can achieve up to 75% efficiency at 20uA load. The device achieves up to 93% efficiency with a 3.3 V to 5V transition at a 200mA load. The above-mentioned three LPS power ICs work together to provide a guarantee for earphones to realize the function of charging for 10 minutes and lasting for 2 hours.
Other configurations on the motherboard of the charging case include a soft pack battery from ZWD, model ZWD802028, with a rated battery capacity of 400mAh/1.480Wh, which can provide up to 20 hours of battery life with earphones.
In the internal configuration of earbuds, 10mm bass dynamic driver is used to bring a more powerful bass experience. In terms of bluetooth functions, BES WT230 bluetooth SoC is adopted, which supports Bluetooth 5.0 dual-mode, and integrates high-performance Cortex-M4F core audio and voice application SoC. Features such as HD call noise cancelling and low-latency game mode. In terms of touch, the earbuds adopts the LONGWECHIP LW8661S single-button touch detection chip, which has the characteristics of low power consumption, fast response, strong power noise suppression and high consistency, and can realize the quick response of the earphone to touch control.
The earbuds use SINOMUC MC9934 8-bit single-chip microcomputer, which is used to trigger the reset to transmit the bluetooth signal again when the earphones fails in the connection, so as to ensure that the bluetooth does not crash. At the same time, it has ultra-low standby power consumption, extending the battery life of the bluetooth headphones. In terms of battery life, the earbuds battery also uses a ZWD soft pack battery with a rated battery capacity of 0.15Wh, providing a single 6-hour battery life. Adopt Hypower HP4554 high input voltage charger with overvoltage protection, input withstand voltage 24V, 6.8V overvoltage protection, charging current and termination charging current are programmable, used for earphones built-in battery charging.
Source: 52audio
Check the realme Buds Q2 price:
- Check price on AliExpress
- Check price on Amazon US
- Check price on Amazon Germany
- Check price on other Amazon countries
