Introduction

As a fan of ChargerLAB, you probably know that the Raspberry Pi has become a go-to choice for tech enthusiasts, hobbyists, and professionals in the realm of computing and DIY projects. Its versatility and compact design make it a favorite among users worldwide. However, often overlooked is the essential component that powers this remarkable mini-computer – the Raspberry Pi power adapter.

Recently, we obtained an original USB-C power adapter for the Raspberry Pi 4. Curious to see the level of craftsmanship behind this small device? Let's delve into it and discover its construction quality together!

Product Appearance

This power adapter uses a pure white cube design with matte surface.

And the classic Raspberry Pi logo is located on the top.

All specs info is printed below the two-prong plug. Model is KSA-15E-051300HU. It can support input of 100-240V~50/60Hz 0.5A, and the output is 5.1V3A. The adapter has passed FCC and UL certifications .

The joint between the output cable and the power adapter has been reinforced.

The USB-C connector also adopts matte design.

The length of this power adapter is about 45mm (1.77 inches).

The width is also about 45mm (1.77 inches).

And the height is about 27mm (1.06 inches).

And the output cable is about 1.7M (5' 6.92''),

This is how it looks like on my hand.

And the total weight is 98g (3.46 oz).

The ChargerLAB POWER-Z KM002C shows it only supports Samsung 5V2A protocol. However, this is quite reasonable since not many people would use it to charge their smartphones or laptops.

Teardown

As always, use a spudger to pry along the gap and open the power adapter, there is a large thermal pad inside to enhance heat dissipation.

The input and output are all connected to the PCBA by soldering.

Here is the AC input end.

And here is the output end.

The Fuse, high-voltage filter capacitor, common mode choke, transformer and capacitor that powers the master control chip are on the front of the PCBA module.

And the bridge rectifier, master control chip, feedback optocoupler and synchronous rectification chip are on the back.

ChargerLAB discovered that this original Raspberry Pi power adapter utilizes QR flyback topology, with the output voltage feedback provided by an optocoupler. The PCB is designed with slots and inserted with an isolation board for insulation between the primary and secondary sides. Now, let's begin our exploration of its components, starting from the input end.

The filter capacitor and transformer are fixed with potting compound.

And the input fusible resistor is insulated with heat-shrinkable tubing.

The bridge rectifier is from Pingwei, the model is ABS210. 2A 1000V.

The high-voltage filter capacitor is from ManYue. 15μF400V.

And the ferrite core of this common mode choke is wound and insulated with yellow tape.

The other two filter capacitors have the same specifications, both are 12μF400V.

The master control chip is from Shengting Micro, model D8548HF, which incorporates MOSFET internally.

And the filter capacitor that provides power to it is 4.7μF50V.

The transformer is also wound with yellow tape for insulation.

The OR1009 optocoupler is used for output voltage feedback.

Moving on to the output end.

There are two solid capacitors and one blue Y capacitor on the output end.

The synchronous rectification chip is from si-power, model SP6536F. It is a high-performance secondary-side control circuit for switch-mode power supplies. It easily meets DOE Level VI efficiency standard under conditions of low voltage and high current.

Additionally, it has extremely low on-resistance. It supports switch frequencies of up to 150kHz and various modes such as CCM/QR/DCM. The low conduction losses result in significantly improved system conversion efficiency, surpassing those of Schottky diodes, and greatly reducing the temperature.

Here is all the information about si-power SP6536F.

These two parallel output filtering capacitors are from Panasonic SEPC series, which are solid capacitors known for their ultra-low equivalent series resistance (ESR).

One last look at all the components of this Raspberry Pi 15W USB-C Power Adapter.

Summary of ChargerLAB

In summary, the Raspberry Pi 15W USB-C Power Adapter features a sleek and minimalist design, with the classic Raspberry Pi logo adorning its matte white cube exterior. It meets all the necessary certifications, ensuring a reliable power supply for your Raspberry Pi.

During our teardown, we observed that the power adapter employs QR flyback topology with optocoupler feedback for output voltage control. Notably, the output filtering capacitors are sourced from Panasonic's SEPC series, known for their low equivalent series resistance (ESR). This feature enhances the adapter's performance by ensuring efficient power delivery and minimal energy loss, improving overall stability.

With its compact size and meticulous internal construction, the Raspberry Pi power adapter stands as a reliable companion for powering your Raspberry Pi projects.

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