With powerline adapters becoming more popular, it's about time one of these was taken apart! In this teardown, we will look inside a TP Link Powerline Adaptor to see what makes this thing tick!

Powerline Adapters

Ethernet power line adapters have become increasingly popular in environments where Wi-Fi can be intermittent or non-existent. While powerline systems have become more mainstream in the past few years, their invention dates back to 1922 when electrical wiring was becoming more popular in houses and streets. The first use of sending signals over power lines was for telemetry purposes with carrier frequencies between 15kHz and 500kHz.

In this teardown, we will see what makes up a standard powerline adapter.

 

Outer Casing

The unit has three LEDs on the front to indicate power, an Ethernet connection, and a network connection.

 

LED indicators and the "pair" button
 

Adapters from different manufacturers are usually compatible but this unit is not compatible with older models (100mbps). This is why such units come in pairs so that one is connected to the main router and the other is connected to the device that requires network access (such as a PC).

This powerline adapter also has a "pair" button, which allows it to be paired with a specific adapter for communication between two points (such as two PCs).

 

Powerline adapter

 

Ethernet connector on the adapter

 

Serial number on the adapter

 

Getting Access Inside

Like many mains-powered devices, this unit has no screws and is molded as to prevent access to the internal high voltages. Therefore, an invasive method is needed to get inside to see how this thing ticks.

In my case, a small drill was used to create a hole whereby a lever was inserted to remove the front cover.

 

Back of the main PCB
 

One IC that can be seen in the top half of the main PCB is the LNK623DG. This IC is for power regulation and constant voltage control, which would make sense considering that this device needs to use AC power as a power source. See the datasheet here.

 

Close up of the top half of the main PCB

 

The bottom half of the main PCB shows a serial flash chip 25Q80 with a capacity of 8 Mbits. Devices like these are used to hold device information such as a MAC address and network configurations. See the datasheet here.

 

Close up of the bottom half of the main PCB

 

Main Connection

With the main PCB, drawn away from the housing, the mains connection becomes visible.

Interestingly, the mains connection is done via uninsulated metal strips which explains the lack of screws. If wires with insulation were used, then security screws would be a suitable construction method. Since this unit uses bare metal conductors, it is better practice to use no screws at all and make it near impossible to gain access inside.

You may also notice a reflective gold piece—this is actually covered in a clear plastic layer. This may be installed for EMC reasons to prevent interference between the mains and the controller board.

 

The mains connection, main PCB, and shielding

 

Mains connection close up

 

Main PCB

The main PCB shows regulation and filtering components including transformers, inductors, and large capacitors. Interestingly, many of the parts are through-hole which makes manufacturing more difficult (a PCB like this may need manual soldering).

 

The main PCB
 

Top of the main PCB


The main controller is an Atheros AR7420-AL3C, which is specifically for LAN networks. The IC includes an ARM CPU, internal ethernet switching, ADC, DAC, SPI, and GPOs. The ethernet controller can handle up to500Mbps PHY rates over powerline connections and has inbuilt hardware encryption (AES 128-bit).


 

The Atheros processor

 

The second IC on this PCB is the Atheros AR1540, which is partnered with the main controller. This is an ethernet line driver supporting between 2MHz and 68MHz operating frequencies, integrated Tx line driver, and a programmable Tx gain control amplifier.

 

The sister IC to the main controller

 

The last main IC on the top layer of the PCB is the AP35502 which is a DC-DC buck converter that can handle up to a load current of 2A with efficiency up to 95%.

 

The DC-DC converter IC

 

Summary

The powerline adapter demonstrates the importance of miniaturization of components when trying to get an entire ethernet network adapter to fit in a small space. The plug of this device is so small that it doesn't prevent other plugs from fitting into adjacent sockets.

The main controller, the Atheros AR7420-AL3C, is a classic example of how microcontrollers are becoming increasingly complex and integrated with inbuilt stacks, encryption, and peripherals with plenty of GPIOs to spare.

 

Thanks for reading! Stop in next week for another Teardown Tuesday!

 

Next Teardown: Pulse Oximeter

 

Comments

1 Comment


  • Rick Sparks 2016-11-26

    this model is for European outlets

    • Robin Mitchell 2016-12-08

      Incorrect, this is a UK Outlet. There is no such thing as a European outlet (there are different ones for different countries around Europe). Also, Europe is not one nation but many countries. Imagine the outrage if I generalized all of America (including mexico and Canada).

      http://www.toycome.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/s/2/s20-2.jpg

      • DakLak 2017-01-31

        The ONLY benefit from having one of the largest physical domestic plug/socket combinations, the UK Monster is perfect for wall-warts and similar applications.

        As a Canadian I can tell you that the NAFTA countries form NORTH America. Our twin flat pin and twin + ground plug/socket combinations can be found all over the world. Their presence, however, should not be taken to indicate the voltage. In Japan, half the country in 115VAC and the other half is 240VAC (nominal).

        The ‘North American’ styles are also to be found all over Indochina where the voltage in 240VAC. (Look at lamps/bulbs to ascertain a country’s voltage)

        The British Monster combination is to be found in Malaysia and Singapore as well as buildings invested in other countries by Singaporeans.

        Of course Monster users pay for the privilege as there are fewer countries using the standard.

        Europe has two-pin and two-pin grounded versions and whilst the plugs appear (and are) different, the sockets have provision for safely accepting the various types. This excludes Switzerland, which has commonality with Liechtenstein & Rwanda.

        However, Euro 2-pin with a flat case (as opposed to round) will safely fit the Swiss socket.

        I see TP-Link has omitted the fuse from their version of the UK socket.

        As a world traveller I have found the best universal ‘plug’ to be a twin-conductor wire, with bared ends, along with a small screwdriver to defeat the child-safe outlets.