Disassembly report: Kosun Kexun Mini 20W PD fast charging charger

Recently, Kexun industry, a well-known power supply manufacturer in the industry, has launched a 65W Gan charger and a 20W Mini PD fast charger. The latter has a compact body and is compatible with all the mainstream fast charging protocols on the market. It can not only provide 20W fast charging for iPhone 12, but also support Huawei's new 22.5w high-voltage SCP fast charging, with very strong performance. Next, the charging head network will be disassembled in detail to see how the design materials are.


1 Appearance of Kexun Mini 20W charger


The charger is made of PC flame retardant white shell, with piano baking paint treatment on the surface. The edges and corners are smooth and the design is simple. Kosun brand is printed on the waist.


The input is equipped with fixed GB pin.


The charger parameter information is marked on the shell

Model: 620036

Input: 100-240V ~ 50 / 60Hz 0.7A

Output: 5v3a, 9v2.22a, 12v1.67a

Manufacturer: Shenzhen Kexun Industrial Co., Ltd

The product has passed 3C certification.

The output top surface is equipped with usb-c interface, and the orange red rubber core does not expose copper. The measured width of charger body is 30.16mm by vernier caliper.

The thickness is 30.2mm.

The height is 30.61mm.

Compared with apple 20W charger, the volume advantage is obvious.

The intuitive feeling of holding it in the hand.

The net weight of the charger is about 36g.

Using chargerlab power-z kt002 to detect usb-c port output protocol, the display supports apple 2.4a, Samsung 5v2a, DCP protocol, qc2.0 / 3.0, AFC, FCP, SCP, pe2.0, pd3.0 and PPS fast charging protocol.

Using this charger to charge Huawei P40 mobile phone, the screen of mobile phone shows "super fast charging", which successfully enters the high-voltage SCP fast charging mode.

The charging power measured by km001c is 8.92V 2.28a 20.35w.

2 Dismantling of Kexun Mini 20W charger

This charger adopts the popular combination welding design of multiple PCB boards, and the primary filter capacitors are insulated with yellow insulating tubes.


The output end of the small board split, you can further see that transformers, capacitors and other devices glued reinforcement.

 iPhone Adapter

The output end of the charger is provided with fuse and NTC surge suppression resistor.


A rectifier bridge is arranged on the back of the small board at the input end.


The specification of delay fuse is 2A 250V.


Wuxi silicon power sp6681 is a high integration, high performance current mode PWM controller, with low power consumption, wide supply voltage characteristics, suitable for wide output range of PD charger scheme. The controller is also an off-line flyback circuit with low cost and high performance price ratio. The control circuit has high conversion efficiency in the whole load range.

 iPhone Charger Adapter

Sp6681 provides complete protection functions, including cycle by cycle over-current, overload, external over temperature, output short circuit, over-voltage and VDD over-voltage protection. IC internal frequency conversion technology achieves excellent EMI effect, and internal frequency control technology minimizes the energy below 23khz to avoid noise. Adopt SOT23-6 package.


Summary of dismantling charging head net


Kexun Mini 20W charger body is square and small, the shell is smooth and white, the design is very simple. The charger supports 20W fast charging, which can meet the current hot 20W market demand; At the same time, it also supports Huawei's high-voltage SCP fast charging, which can carry out 22.5w fast charging for Huawei P40 and other new mobile phones. In addition, it also supports Q, AFC, FCP, pe2.0, PD and PPS fast charging protocols, so the overall compatibility is very good. In the case of mini charging, it has more advantages.


The switching power supply part of this charger uses silicon power sp6681 master control, with China Resources micro primary switch MOS, and silicon power secondary synchronous rectifier chip sp6518f. The copper leakage, tin addition and via treatment on the connecting board and output board help the chip heat dissipation. The output protocol chip adopts Zhirong sw2303, which is a high-performance protocol IC specially designed for 20W Mini charging. It supports private fast charging protocols such as SCP and vooc, and has obtained qc4 + certification, which is very reliable.