As fast charging for smartphones has become ubiquitous, entry-level smartphones and various digital accessories are increasingly compatible with PD fast charging. Consequently, the demand for cost-effective 20W PD fast chargers remains robust.
Chongdiantou recently obtained a 20W USB-C fast charger designed for the Indian market. This charger supports multiple fast charging protocols including PD3.0, PPS, QC, SCP, and AFC, meeting the fast charging needs of smartphones and IoT devices.
Below is a detailed teardown of this product to examine its internal build quality and component selection.
Product Appearance
The charger features a white flame-retardant PC housing. The body surface utilizes a vertical three-dimensional stripe texture, offering good anti-slip and anti-scratch performance along with a comfortable grip. The input end is equipped with fixed Indian-standard dual round-pin plugs.
The output panel has a slightly convex design, featuring a single USB-C output port in the center, with rounded transitions on the housing.
From the side view, the overall edges of the charger feature smooth and natural chamfers, presenting a compact and neat appearance.
The corners and edges of the body are treated with rounded chamfer transitions, while the fine vertical凹凸 stripes on the surface are evenly and delicately processed.
A close-up of the output panel shows a single USB-C interface, with an orange core inside the female connector.
The input end features laser-engraved product parameters:
Model: Adapto 20X
Input: AC 180-240V ~ 50/60Hz 0.6A (MAX)
Output: DC 5V3A, 9V2.22A, 12V1.67A (20W Max)
Made in China
Close-up of the Indian-standard metal pins, which are nickel-plated.
Product Dimensions and Weight
The measured length of the charger body is approximately 42.73mm.
Using vernier calipers, the width of the charger body was measured at approximately41.73mm.
The thickness of the body was measured at approximately 29.30mm.
Weighing the charger on an electronic scale showed a weight of approximately 41.6g.
Placing the product in an adult male's palm demonstrates its size as shown in the image.
Compared with Apple's original 20W charger, the two have similar volumes.
Fast Charging Protocol Analysis
Testing with the POWER-Z KM003C revealed that the USB-C port supports various mainstream fast charging protocols including QC3+, FCP, SCP, AFC, PD3.0/PPS, QC4+, and DCP.
Further reading of the PDO messages from the USB-C port indicates three fixed voltage levels: 5V3A, 9V2.22A, and 12V1.67A, along with one PPS voltage level ranging from 5.00-11.00V at 2.00A.
Having briefly reviewed the product appearance and fast charging compatibility, we now proceed to the teardown section.
PCBA Overview
After removing the housing, the internal PCBA module is visible. There is a clear distinction between high-voltage and low-voltage areas. Components such as high-voltage filter electrolytic capacitors, differential mode inductors, transformers, and output solid capacitors are reinforced with white thermal adhesive to aid heat dissipation.
The input end uses clips to connect to the pins for power extraction.
The front of the PCBA module features EMI filtering circuits, high-voltage filter capacitors, the transformer, low-voltage filter capacitors, and the USB-C female connector.
The back of the PCBA module contains the rectifier bridge, primary controller chip, SMD Y-capacitors, optocoupler, synchronous rectification chip, and protocol chip.
Primary Side Circuit Analysis
Close-up of the input fuse, used for overcurrent protection.
Close-up of the NTC thermistor, used to suppress inrush current when the charger powers on.
The input SMD rectifier bridge has the marking ABS210 and uses ABS packaging.
The high-voltage filter capacitor is from Ketuo.
On the other side, the specification is marked as 450V 15μF.
The primary controller chip has the marking LX3726 and uses SOP-8 packaging. The chip integrates a high-voltage power switch internally.
The transformer is ink-jet printed with XED 1512-002 XDWY 2637.
One SMD Y-capacitor is from Sichuan Terui Xiang Technology Co., Ltd. It features small size and light weight, making it ideal for high-density power products like GaN fast chargers. The part number is TMY1102M.
Datasheet information for the Terui Xiang SMD Y-capacitor.
An optocoupler is from Everlight, model EL817.
Secondary Side Circuit Analysis
The secondary synchronous rectification chip has the marking LX1709 and uses SOP-8 packaging. It includes an integrated synchronous rectification controller and synchronous rectification MOSFET.
The protocol chip is from JADARD, series JD6617. This series is specifically designed for USB Type-C Source-side fast charging protocol control, supporting the latest USB PD 3.2 SPR specification and compatible with PPS and AVS voltage adjustment.
The chip supports a wide working voltage range of 5V~21V and 3A output current. It integrates a constant voltage control loop, driving the optocoupler via the OPTO pin to achieve secondary-side voltage regulation, with a maximum voltage step precision of 20mV.
The JD6617 is compatible with mainstream fast charging protocols including Qualcomm QC 2.0/3.0/3+, Huawei SCP/FCP, Samsung AFC, Apple 2.4A, and BC 1.2. The chip allows flexible configuration of power and PDO by connecting a single resistor to the RPDO pin, covering multiple power settings from 15W to 60W, enhancing solution development convenience.
In terms of safety, the JD6617 integrates a VBUS quick discharge circuit with approximately 100mA discharge capability, along with overvoltage protection and undervoltage lockout. The USB interface has an HBM ESD protection rating of 4kV.
The chip uses SOP-8 packaging and supports designs with or without external VBUS pins. With minimal peripheral components, it is highly suitable for fast charging, wall socket panels, and power strip applications.
An output filter capacitor is from APAQ, with a specification of 16V 680μF.
Close-up of the USB-C output female connector, showing the orange core inside.
Teardown complete. Here is a group photo of all components.
Conclusion
Finally, here is the bill of materials (BOM) for reference.
This India-labeled 20W USB-C charger uses a flame-retardant PC housing. The three-dimensional striped texture on the surface provides a comfortable anti-slip and anti-scratch grip. The unit is compact and supports QC3+, FCP, SCP, AFC, and PD3.0 fast charging protocols, meeting the charging needs of smartphones and IoT devices.
Through the teardown, Chongdiantou found that the internal primary controller chip is the LX3726, and the secondary synchronous rectification chip is the LX1709. Paired with the highly integrated JADARD JD6617A protocol chip, it achieves 20W output. The entire solution features high chip integration, significantly reducing the number of peripheral components and BOM costs.
Additionally, the high-voltage filtering uses Ketuo high-voltage electrolytic capacitors, the SMD Y-capacitors between primary and secondary sides are from Terui Xiang, and the output filtering uses solid capacitors. Components are secured with adhesive.
Overall, the product design is simple, effectively controlling BOM costs while ensuring stability and fast charging compatibility.