Faulty 120W charger analysis (Anker GaN Prime)

Summary

In this detailed teardown, the creator dives into diagnosing and fixing a malfunctioning 120W GaN charger. They walk through the process of identifying the issue, which is a short circuit caused by a damaged component. The video explores the charger’s intricate design, highlighting the challenges of working with such advanced technology. With expert analysis, the creator also demonstrates the complexity behind the components, providing valuable insights into GaN charger technology. The creator expresses gratitude to their supporters for making the channel possible and keeping it running.

Takeaways

• 😀 The video explores a failed 120W gallium nitride charger, donated by a viewer, aiming to understand its failure and internal workings.
• 🔧 The charger features two USB-C ports (up to 100W each) and one USB-A port (up to 22.5W), with a total output capacity of 120W.
• 🔎 Despite its initial appearance as a high-quality charger, the device failed to function, with no voltage detected on any of the ports.
• 🛠️ The internal components were encased in resin, making it difficult to open and inspect, though the charger was eventually disassembled with effort.
• 🔌 Inside, the charger has four main boards, with components like capacitors, inductors, rectifiers, and MOSFETs, crucial for its operation.
• ⚡ The charger uses a hybrid flyback topology, which includes a gallium nitride half-bridge and an active clamp circuit for efficient power conversion.
• 💡 Some components, such as MOSFETs, are used for synchronous rectification and voltage regulation for multiple ports.
• 🔋 A short circuit was initially suspected in a capacitor, but the issue was traced back to a faulty communication chip controlling the voltage negotiation.
• 🛠️ The process of identifying the faulty component involved using a thermal camera to locate overheating parts, which led to the discovery of the defective chip.
• 🧑‍🔬 The dissection revealed the transformer used in the charger was a printed transformer with a unique construction, including a split core and multi-layer windings.
• 🔋 In addition to the charger, the viewer also donated 18650 cells, which were tested for capacity, with one cell proving particularly suitable for use in a headlamp.

Q & A

What is the main issue with the 120-watt gallium nitride charger featured in the video?

The charger stopped functioning, and there is no voltage output from any of the ports. The video explores the potential causes of failure inside the charger.

How was the charger’s internal structure and components tested?

The charger was opened by carefully cutting through the casing, which was filled with resin. The internal components were inspected, and various measurements were taken to identify potential faults.

What is the significance of the resin inside the charger?

The resin is used for protection and interference shielding, but it makes the disassembly process extremely difficult, as it solidifies the components inside.

What types of components are used in the charger’s circuit?

The charger uses various components including synchronous rectifiers, MOSFETs, diodes, capacitors (both electrolytic and ceramic), inductors, and opto-couplers. There are also several chips that manage power regulation and communication.

What was the primary issue identified after the charger was disassembled?

The primary issue was a shorted capacitor, which appeared to be causing the malfunction. Despite attempts to isolate the issue, the root cause was traced to a faulty chip involved in communication and voltage regulation.

What role does the power factor correction (PFC) play in the charger’s design?

The power factor correction ensures that the charger efficiently converts power from the AC input, reducing losses and improving the charger’s overall efficiency, especially with a high output of 120W.

How do the different MOSFETs in the charger function?

The MOSFETs serve multiple roles: some act as synchronous rectifiers for efficient power conversion, while others function as voltage regulators for different outputs or disconnect outputs when necessary.

What is the significance of gallium nitride (GaN) transistors in this charger?

Gallium nitride transistors are used for their efficiency and high voltage rating. They enable the charger to handle higher power levels, like 120W, while maintaining a smaller form factor compared to traditional silicon transistors.

How is the charger able to provide different voltages to its USB ports?

The charger uses separate chips to manage each port’s voltage independently, allowing each USB port to negotiate different power levels through protocols, such as Power Delivery (PD), based on the connected device’s needs.

Why was the thermal camera used during troubleshooting, and what did it reveal?

The thermal camera was used to identify which components were heating up during testing. It helped pinpoint the faulty chip responsible for the short circuit, as it became hot while the other components remained cool.