CX8850, 5V input 5V output, 3.6A multi port PD power charger solution, free CX8850 specifications, CX8850 samples, and DEMO board testing.

The CX8850 is applied to the Belkin 30W USB PDUSB PD dual port car charger solution. The appearance design of the Belkin car charger is simple, and the A port supports the APPLE2.4A protocol, which has good compatibility with digital products such as iPhone and iPad; At the same time, the USB-C port supports 18W PD fast charging, which can be used for flagship series phones of iPhone X/XS series, Samsung, Huawei, Xiaomi, and other brands. At the same time, the USB-A port and USB-C port are designed with independent outputs, which can still output full power when charging two devices, improving the user's charging experience.

1、 Belkin 30W USB PD Car Charging Appearance

The outer packaging of the product still adopts the traditional Belkin style, with a window design on the front, which allows you to see the approximate appearance of the internal product. This is a car charging set, which includes a USB-C charging cable in addition to the car charging body. As can be seen from the parameters on the left side of the packaging box, the cable is 1.5 meters long.

The back of the packaging box is printed with a detailed compatibility list for this car charger, including models such as Samsung Note9, Samsung S9/9+, Samsung Note8, Samsung S8/8+, LG G5/G6/G7, LG V35/V40, Google Pixel3/Pixel3 XL, Google Pixel2/Pixel2 XL, Google Pixel/Pixel XL, iPad Pro, etc.

Open the packaging box, and the charger and charging cable are fixed with a white plastic lining. The overall packaging is relatively light and the shock absorption effect is also good.

In addition to car charging and charging cables, there is also a user manual in the packaging box.

The USB-C to USB-C charging cable has the brand studio by belkin engraved on the interface, and is made of woven wire.

This car features a pure black body and a bright baking paint treatment on the surface, making it look very smooth. The side of the body is printed with the words' studio by belkin '.

From the parameter information on the charging body of the car, it can be seen that this product supports a maximum output of 30W. The product model is F8J251, with an input voltage of DC12V. The USB-A port outputs 5V/2.4A, and the USB-C port outputs 5V/3A and 9V/2A; The product has passed FCC certification.

The output USB-A interface and USB-C interface are designed side by side with black tongue design, and there is an LED indicator light next to them.

The size of the car charging output end is similar to a one yuan coin.

After connecting to the power supply, the LED indicator light turns green.

Using ChargerLAB POWER-Z KT001 to detect the output protocol of the USB-A port, it shows that it supports Apple 2.4A and does not support other fast charging.

Continue to perform protocol testing on the USB-C port, which shows support for the USB DCP charging protocol.

The PDO message display of the USB-C port supports USB PD3.0 fast charging, outputs 5V/3A, 9V/2A, and has a maximum power of 18W, which is consistent with the nominal parameters.

The net weight of the vehicle is approximately 26g.

2、 Belkin 30W USB PD Car Charging Disassembly

Belkin adopts Ultrasonic welding technology for the car charger shell, which is rare in the car charger products we disassembled. Generally, Ultrasonic welding is common in chargers with AC input. There is a white reflector next to the internal PCBA, which aims to gather LED light and make it shine through the small holes on the output panel.

Remove the internal PCB board. The back of the PCB board uses two main control chips and one protocol chip

The output protocol chip of the USB-C interface comes from Hynetek, and the model is HUSB338L. This is a high-performance and highly integrated USB Type-C Power Delivery controller that integrates protocols such as PD3.0, PD2.0, PPS, HVDCP, BC1.2, etc. At present, HUSB338L has passed USB PD2.0 certification (TID number 1000151, XID number 0005398) and USB PD3.0 certification (TID number 1000189, XID number 0005399), with two packaging forms: SOP-14L and QFN-16L, suitable for applications such as power adapters, car chargers, and mobile power supplies.

Hynetek HUSB338L specification information, and the Banker 18W USB PD charger also uses the HUSB338L protocol chip. It is worth mentioning that Hynetek's HUSB338A/HUSB338L/HUSB339 has assisted multiple customers in obtaining USB-IF PD3.0 and MFi PD certification for their products.

In addition, the USB-C interface also uses a Techcode TDM3307A as the VBUS switch.

The main control chip of the car charging power supply comes from CXW, model CX8850. CX8850 is a step-down DC-DC converter with an input withstand voltage of 40V and can achieve precise constant voltage and current. It is built-in with 20m Ω High side N MOS and 20m Ω Low side NMOS, and can support 4A continuous output current and adjustable output voltage, with a maximum support of 98% duty cycle.

The other car charger main control chip, also known as the Chengxin Micro CX8850, uses two Chengxin Micro CX8850 controllers to achieve two independent outputs.

From right to left on the front are output filter inductance, input filter Electrolytic capacitor, two step-down inductors, two output filter solid capacitors, and two output interfaces. Glue injection treatment is used between the step-down inductor and the output filter capacitor to provide heat dissipation and fixation.

The USB-C port uses a small PCB board to be welded with the main control PCB, and the board is sunk.

The positive pole of the input end is directly connected by a spring, and a metal baffle is welded at the end of the spring to enhance reliability and avoid deformation of the spring under excessive pressure.

Input filter Electrolytic capacitor from AiSHi, specification 35V 10 μ F. 3R3 filtering inductance.

The USB-C output filter capacitor specification is 16V 470 μ F. The USB-A port output filter capacitor specification is 6.3V 330 μ F.