Not long ago, Xiaomi just released a 65W dual-port GaN fast charger.
Yeah, the one we had tear it down several days ago.
You can click here to see it.
OK, back to our today’s charger, the ZMI 65W dual-port GaN fast charger.
So, what’s the difference between this charger and Xiaomi version?
ChargerLAB will disassemble it and tell you the answer.
The packaging of the charger is still the ZMI style.
It adopts small paper packaging, which is very environmentally friendly and easy to transport.
The charger is designed with folding pins and supports USB-A and USB-C.
Product specifications are printed on the back.
Model is HA729.
When you use one port, USB-A supports up to 18W.
USB-C supports up to 65W.
When you use dual ports, USB-A also supports 18W.
USB-C reduced to 45W.
Let’s unpack the box The box contains the charger, cable, and manual.
The length of the cable is about 1.5 meters (4.92 ft.)
Use ChargerLAB POWER-Z KM001C to test, It supports 20V5A 100W but only USB2.0 standard.
The charger is entirely black.
It has USB-A, USB-C and adopts foldable pins.
The upper side is bright, and the lower side is matted.
We can also see the 65W and GaN marks here.
Let’s see the charger pins side, We can find it supports 100-240V~ 50/60Hz
wide-voltage input and 1.7A current.
That means we can use it in most countries and regions around the world.
Next, let’s see the size of the charger.
Length, width, and height are about 72mm×31mm×31mm (2.83*1.22*1.22 inches).
Weight is about 104g (3.67oz).
Compare with Xiaomi 65W dual-port GaN charger.
Except for the colors and shell, it seems like the rest of the things are all the same.
But compare with Apple’s 61W charger, We can see how small ZMI charger is.
Let’s use ChargerLAB POWER-Z KT002 to test the supported protocol.
USB-A supports Apple 2.4A, Samsung 5V2A, DCP, QC2.0 and QC3.0 protocol.
USB-C supports Samsung 5V2A, DCP, QC2.0, QC3.0, PD3.0, PPS protocol.
In addition, the USB-C also supports 5V3A, 9V3A, 12V3A, 15V3A, 20V3.25A
five fixed PDOs and 5-11V5A & 5-20V3.25A two sets of PPS PDOs.
OK, time is up.
So, what is the internal structure of this charger?
Let’s find it out.
After cutting the shell, We can pull out the entire PCB module.
The charger module is covered with pure copper heat sink.
There is a plastic shell on the input end.
The contact adopts ENIG (electroless nickel immersion gold) design.
There are also heat sinks and isolation plates on the back of the motherboard.
The low-voltage side is wrapped by tape to enhance insulation effect.
The heat sink is soldered on the motherboard.
Continue to remove the heat sink.
There is a thermal pad between the components and the insulating board to help heat dissipation.
The input end is covered with a plastic plate, to support heat sink.
After our analysis, this charger uses a high-frequency QR flyback topology architecture.
This is master control chip, which uses GaN technology to achieve high-frequency switching and high efficiency.
And the charger adopts planar transformers to achieve the small size.
You can also see, The component layout of the entire PCB module
is very compact.
The output of USB-C is directly controlled by the protocol chip.
The output of USB-A has a step-down circuit.
We continue to remove the small board of input end.
“Design by Cuktech” printed on the PCB.
One of the PCB is responsible for the EMI filtering, and has fuse, safety capacitor
and common mode chock on it.
Another PCB has two rectifier bridges, which use to rectify high-voltage alternating current
into high-voltage direct current.
Remove two capacitors.
The big and small electrolytic capacitors for high-voltage filtering are from Aishi.
They are 400V 100μF and 400V 18μF.
It can form a π-type filter with the differential mode inductor.
The small capacitor is used for switching ripple current.
Large capacitor is used for rectification and filtering.
The master control chip adopts ON Semiconductor NCP1342.
This is also the most widely used chip for GaN chargers.
Then, here is the highly integrated GaN power chip of Navitas NV6115, which has built-in driver and GaN switch tube.
Navitas is the industry’s leading GaN chip manufacturer.
The industry’s first mass-produced GaN fast charger uses chip from Navitas.
The well-known brand, such as Xiaomi, OPPO, Lenovo, ANKER, Baseus, Belkin are all using it.
At present, its shipments have reached 20 million but zero failure rate, which is pretty awesome.
Here is an optocoupler for voltage feedback.
And two Y capacitors in series are next to it.
And then, let’s see this PCB of transformer.
This charger uses a planar transformer.
At present, the cost of planar transformers is higher than traditional transformers.
But for the small size, planar transformer is the best choice.
It also integrates a synchronous rectifier circuit on the PCB of transformer.
An MPS synchronous rectifier chip is on the secondary side.
Model is MP6908A.
Its maximum operating frequency can reach 600KHz, designed for GaN fast charging.
A synchronous rectifier MOS tube is next to it, from Toshiba.
On the other side is the protocol chip from Cypress CYPD3174.
This chip can control the output of USB-A and USB-C.
Cypress is also the supplier of Apple fast charging.
So does ZMI.
The VBUS switch tube of USB-C is also from Toshiba.
You can see that this interface is customized.
There are two solid capacitors next to USB-C, used for synchronous rectification and output filtering.
Let’s take a look at the USB-A output circuit.
It adopts a buck-boost chip from Southchip SC8721,
cooperates with Cypress’s protocol chip to achieve USB-A output.
This chip integrated four-channel H-bridge buck-boost switch tube.
And supports I2C bus to control output voltage and output current.
At the same time, the USB-A uses a Kemet tantalum capacitor to filter output,
which is expensive and usually only used on high-end power products.
The purpose of using it is also to make the charger smaller.
Dust-proof stickers are attached to the USB-A. There is a buck-boost inductor on the back of the small board.
Well, that will be today’s teardown of ZMI 65W dual-port GaN fast charger.
Compared with Xiaomi 65W dual-port GaN fast charger.
The difference will be appearance, especially color.
But its performance and architecture are exactly the same as Xiaomi version.
The PCB and main chips have not changed.
So anyway, you can choose color you’d like and buy which brand you’d like.
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and you can see the teardown of other Xiaomi or ZMI products on your right side.
See you next time.
Bye.