Teardown Report: Belkin MFM Certified Two-in-One 20W Wireless Charger
Apple iPhone 12 adopts the new MagSafe magnetic wireless charging method for wireless charging and supports up to 15W wireless fast charging. This new wireless charging method immediately detonated the third-party wireless charging market, and various styles of magnetic wireless chargers have been come up one after another. But no matter how it is designed, the charging power is only 7.5W at most.
However, the MagSafe magnetic wireless charging module certified by Apple’s MFM (Made for MagSafe) has been mass-produced. Brands such as Belkin, which has long-term cooperation with Apple, have designed various wireless charger products based on this module. Today, the ChargerLAB disassembled the Belkin MFM certified two-in-one wireless charger. This product can charge iPhone 12 and AirPods simultaneously, and the power is 15W and 5W respectively. So let’s take a look at the details of this product.
1. The appearance of the Belkin 2-in-1 wireless charger
The front center of the box is printed with a picture of when this wireless charger is using, which can wirelessly charge the iPhone 12 and the AirPods simultaneously. The logo of Belkin and the 15W logo printed on the top, the name of the product and the MFM certification logo printed on the bottom.
The product bullet points and product schematic diagram are printed on the back, iPhone 12 can be charged wirelessly no matter which direction it rotates.
A list of Apple applicable devices printed on the side, including iPhone 12 series models, AirPods series and official MagSafe cases.
The package contains a wireless charger, adapter and instruction manual.
The adapter adopts a “racetrack” design, with the logo of Belkin printed on the top, and comes with a DC output cable.
Technical specifications are marked on the charger input shell
Model: 2ACR040G CN
Input: 100-240V~50/60HZ 1.3A
Manufacturer: Qiaowei Technology Co., Ltd.
The cable is bound with a rubber ring, and the output side is a DC round port.
Belkin’s wireless charger consists of three parts: a chassis, a support rod, and a mobile phone magnetic wireless charging board, the design is immaculate and comfortable.
The support rod is bent, so that the magnetic wireless charging board has a certain inclination, and the experience of using it while charging is better.
The mobile phone wireless charging board has a magnetic design. The iPhone 12 can be attached when it is close to the board and can be wirelessly charged at any angle.
The pedestal shell is frosted, and the wireless charging area is concaved.
It will be more stable when the AirPods’ case is placed on top.
There is an LED indicator on the edge of the groove.
Belkin logo printed on the front.
Four anti-skid pads are stuck to the bottom of the pedestal, and product specifications are printed on the shell.
Input: 33W (15V2.17A)
Output: 5V-20W (iPhone: 15W, AirPods: 5W)
Products have passed CE, EAC, KC, NOM, NYCE, RoHS and other certifications.
Actual scenes of wireless charger, supporting simultaneously charge to iPhone 12 and AirPods.
2. Belkin 2-in-1 wireless charger and teardown
The pedestal is packaged with screws.
The outer shell can be opened by removing the screws.
A heat-dissipating aluminum plate is fixed on the bottom shell.
The other half of the shell is fixed with counterweights on both sides, and a PCB board is placed in the middle and fixed with screws.
There are thermistors and wireless charging coils on the front of the PCB board, and the solder joints on the PCB board are reinforced by injection molding.
Close-up of the PCB’s back, the corresponding parts of the coil and capacitor are hollowed out to help dissipate heat and reduce thickness.
After observation, it is found that there are two step-down circuits on this circuit board, which are used to power the wireless charging circuit of headphone and mobile phones—also, the headphone wireless charging circuit, which uses NuVolta wireless controller and driver. Next, let us start from the input end to know the information of each circuit.
Close-up of the DC input female.
Close-up of the input filter inductor.
The input protection tube adopts VS3510AE, with a withstand voltage of 30V, and PDFN3333 to package.
Details of Wei Zhao VS3510AE.
ChargerLAB found that the Miwu 3A1C seven-in-one multifunctional dongle, Xiaomi 55W vertical air-cooled wireless charger, Xiaomi smart tracking wireless charger, Turas 30W 1A1C USB PD fast charger, Xiaomi 30W vertical air-cooled wireless charger and other products also use VS3510AE by WeiZhao semiconductor.
The MPS MP2315 synchronous step-down converter has an input voltage of up to 24V and a maximum output current of 3A, providing power for headphones with step-down wireless charging.
Details of MPS MP2315.
10μH alloy step-down inductor.
AirPods wireless charging transmitter control chip adopts NuVolta Semiconductor NU1509, integrates ARM-M0 core, covers high-precision FOD algorithm, complies with WPC1.2.4 EPP protocol, controls high-precision PWM output, supports LED indication of charging status, it also has built-in fast charging protocol, and support complete and comprehensive protection to meet the customized needs of various customers.
Details of NuVolta NU1509.
NuVolta Semiconductor NU1009A, which is integrated power-level full-bridge MOS tube, used for wireless charging and transmission, has a built-in switching regulator and LDO to power main control IC, and built-in high-precision current detection and demodulation, I2C communication, which integrated complete protection functions.
Details of NuVolta NU1009A.
The special MPP wireless charging capacitor made by KYET(科雅), 0.4μF, withstand 100V voltage.
The wireless charging coil is tightly wound, and the thermistor is fixed in the center for temperature monitoring.
Close-up of the LED indicator.
The step-down chip on the other step-down circuit is attached with a thermal pad, and the step-down inductor covers the shield.
Remove the shield, the inductor also pasted with a graphite sticker.
Texas Instruments TPS54335A can input up to 28V, 3A output synchronous step-down converter, it has built-in switch tube, can adjust the operating frequency. For example, step down the input to power the mobile phone MagSafe magnetic wireless charging module.
Details of TI TPS54335A
15μH alloy step-down inductor.
Yongming (永铭) NPX series filter solid capacitors, the technical specification is 16V 330μF. This series of capacitors’ characteristics will be small size, low ESR, high allowable ripple current, and high reliability.
ChargerLAB found, NPX series solid capacitors have been previously used on SHARGE 100W 3C1A GaN fast Charger, Momax 65W 2C1A GaN fast charger, Baseus 45W 1A1C GaN charger, Nubi 65W GaN charger and other products, in addition, it also applied in PISEN, Benks on other brands of 20W mini-charger.
A filter inductor.
The wire on the back of the support rod is covered with the insulating tube.
Disassemble the magnetic wireless charging board, and fix the white plastic shell with screws.
The MagSafe magnetic wireless charging module is packaged in a black plastic shell and a metal shield.
Tear off the front plastic plate, you can see a cycle of magnets on the edge of the wireless charger, which is fixed by glue.
An induction coil is stuck to the plastic board.
A metal shield is arranged between the wireless charging coil and the PCB board, and the edge is fixed by spot-welded, and the corresponding PCB board is pasted with insulating paper.
The magnetic ring is made of 16 tiny magnets.
Take out the PCB board, and the insulating paper is also pasted on the metal shell.
All of the components on the PCB board are on the same side.
Close-up of filter inductor.
Load switch with 1324V mark.
Texas Instruments’ TPS61178, boost converter.
The diode with the X2 H1 mark, which is used to improve the boost conversion efficiency.
It’s a 3.3μH alloy inductor for boosting.
The step-down IC from MPS will power the wireless charging microcontroller.
It’s the Type-C port controller from Cypress CYPD2104.
The main control chip of the wireless charger adopts ST STM32F446MEY6, high-performance BUT basic series ARM Cortex-M4 MCU with DSP and FPU, with 512 KB Flash, 180 MHz CPU, ART accelerator and dual QSPI.
Details of ST STM32F446MEY6.
There is a crystal oscillator next to it to provide the clock for the main control chip.
ST STWPSPA1 is the customized wireless charging controller, packaged by CSP, driven by built-in power MOS tube, and simplified peripheral components. According to the iPhone12 MagSafe magnetic wireless charger IC-level analysis report, this controller also contains two power tubes and set up two power tubes to form an H bridge.
It can be seen from the DECAP diagram that there are two built-in MOS tubes on the right side of the STWPSPA1 chip, which form an H-bridge with the two external MOS tubes on the chip to drive the wireless charging coil.
Two coils drive MOS tube and five white NPO resonant capacitors.
The wireless charging coil is wound with Litz wire
After the entire teardown complete, let’s take a “family portrait.”
Summary of Teardown of ChargerLAB
Belkin’s two-in-one wireless charger has a minimalist design. It consists of three parts: the pedestal, the support rod and the wireless charging board designed by the MagSafe magnetic wireless charging module. The vertical structure does not take up too much space on the table. The mobile phone can be charged wirelessly. At the same time, it can be charged no matter how it is placed, so it will be more convenient to watch the drama while charging.
LargerLAB also found that on the bottom PCB board, the headphone wireless charging part adopts the NuVolta Semiconductor NU1509+NU1009A and the MPS MP2315 step-down voltage ship is used to power. Besides, the mobile phone wireless charger is powered by TI TPS54335A step-down voltage chip, and its circuit is also integrated on the board, the chip attached to a thermal pad, the inductance covers the shield, and the details are exquisite. The MagSafe magnetic wireless charging module for mobile phones is a standardized, mass-produced product, and the circuit and the components have not changed.
It is reported that Belkin’s wireless charger’s PCBA design was provided by NuVolta Semiconductor completely. It seems that NuVolt not only provided single-chip solutions, but has expanded to customization and development services.