Skyworks Solutions, Inc. is a US-based semiconductor company that formed in June 2002 through the merger of the wireless communications business of Conexant Systems and Alpha Industries. Specialising in many different types of components including radio-frequency and wireless connectivity technologies, Skyworks offer a wide range of evaluation boards that allow engineers to test their products before committing to a full production design. For much more information you can check out their site at:
You can email me at james.boshikoopa@gmail.com
In September 2026 I bought from eBay a job lot of 22 Skyworks Solutions, Inc evaluation kits for £25 + £8.50 p&p or £33.50 ($45.31) total, which works out, if not including the shipping, £1.14 ($1.54) each. The kits were sold as brand new but from the eBay listing I could only find one product ID, SI86SSXX-KIT, but I'm glad I took the risk as there were actually different types of evaluation kits, which you can read about in the various sections.
This is what I received:
Product ID: SI3406FB12V2-KIT
Quantity: 1
Product ID: SI3406FB5V2-KIT
Quantity: 1
Product ID: SI85853-KIT
Quantity: 3
Product ID: SI85855-KIT
Quantity: 3
Product ID: SI85857-KIT
Quantity: 10
Product ID: SI86SSXX-KIT
Quantity: 4
All of the boxes had date of December 2023 printed on them and as the boxes were sealed I didn't do a large amount of testing, just enough to understand how the kits work but Skyworks provide plenty of information to learn in detail how the kits work
The total price going by MSRP is £328.86 ($438).
The product page can be found at:
https://www.skyworksinc.com/en/Products/Power/Evaluation-Kits/Si3406FB12V2KIT
It’s described as ‘Si3406 Isolated 7 W, 12V Class 2 Evaluation Kit’.
There is a description, which I’ll repeat here:
The Si3406 12 V Class 2 evaluation kit demonstrates a complete isolated 7 W Power over Ethernet PD system using our Si3406 PoE PD device. A single Si3406 manages the PoE interface and dc-dc conversion. The Si3406 PD integrates an internal rectifier bridge, detection circuit, classification circuit, dc/dc switch, hotswap switch, TVS overvoltage protection, dynamic soft-start circuit, cycle-by-cycle current limit, thermal shutdown, optional synchronous secondary rectification driver, automatic and user-mode MPS functionality, and inrush current protection. The isolated flyback converter outputs up to 0.45 A for a total power of 7 W while using a standard, off-the-shelf transformer. The Sifos IEEE compliance report, schematics, and layout, are all found in the User’s Guide.
It lists MSRP of $99.00 (£74.65).
There are links to reference manuals (LinkCom PC07xx-001R-A Transformer Second Source for Si3406-ISO-FB-EVB and LinkCom PF07xx-001LR Transformer Second Source for Si3406-ISO-FB-EVB), schematics and layouts, and user guide files.
I unsealed the box, inside was a card with SKYWORKS written on one side and on the other:
Get started!
Find documentation and software at:
The link takes you to a page with a list of power evaluation kits.
The board was in a sealed anti-static bag with label 'Si3406FB12V2-EB', wrapped in anti-static bubble wrap. The board is much, much smaller than the box, probably to save money by using the same size box for multiple different types of products.
The PCB features a mounting hole in each corner with plastic standoff already attached. In one corner printed on the PCB is 'Si3406-EVB-ISO-FB Rev 4.0 SKYWORKS'. There is an ethernet (RJ45) socket on one end, and across the board a couple of headers, various test points, and two banana plug sockets on the other end for power. The main IC is Si3406. Datasheet: https://www.skyworksinc.com/-/media/Skyworks/SL/documents/public/data-sheets/si3406x-datasheet.pdf
On the back of the PCB is a sticker declaring 'Si3406-ISO-FB-R4.2-12V'.
Schematics and Layouts file (Si3406FB12V2KIT.zip), downloadable from skyworksinc.com, contains folders:
The bom folder contains SI3406-EVB-ISO-FB-12V-BOM.pdf Bill of materials for evaluation board SI3406-EVB-ISO-FB-12V. Doc dated 10/19/2022, revision 4.2.
The layout folder contains si3406-evb-iso-fb.pcb, si3406-evb-iso-fb-r4.2.zip, and si3406-evb-iso-fb-r4.2-asc.zip, which are various PCB design software files.
The schematic folder contains SI3406-EVB-ISO-FB.dsn (compatible with various schematic design software) and SI3406-EVB-ISO-FB-12V-SCH.pdf (evaluation board SI3406-EVB-ISO-FB-5V schematic dated October 19, 2022).
I actually tested the similar SI3406FB5V2-KIT (see section below) before SI3406FB12V2-KIT so it would be worth reading that section first as I went into detail about the shared user guide and testing. However, the key difference, which we can see on page 1 of the user guide, is that the SI3406FB12V2-KIT is rated for output voltage/current 12V/0.45A.
For testing I used the same approach as the SI3406FB5V2-KIT. Unloaded I measured voltage across J1 and J2 and got 11.90V. Using a power resistor across the load to draw close to max current the resistor I happened to have drew 470mA (above the limit) but the voltage only dropped to 11.87V. This only slight voltage drop is quite impressive and although the maximum current is less than SI3406FB5V2-KIT it shows you can draw more current than stated.
Lastly, I used my oscilloscope and found that it took 14.16ms to go from 0V to 11.90V.
All these readings seem reasonable for the kit and is a good sign it’s working as expected.
As with SI3406FB5V2-KIT, I couldn't find board dimensions stated anywhere for SI3406FB12V2-KIT but they're the same as SI3406FB5V2-KIT so please see that section for the details.
The product page can be found at:
https://www.skyworksinc.com/en/Products/Power/Evaluation-Kits/Si3406FB5V2KIT
It’s described as 'Si3406 Isolated 7 W, 5V Class 2 Evaluation Kit'.
There is a description, which I’ll repeat here:
The Si3406 5 V Class 2 evaluation kit demonstrates a complete isolated 7 W Power over Ethernet PD system using our Si3406 PoE PD device. A single Si3406 manages the PoE interface and dc-dc conversion. The Si3406 PD integrates an internal rectifier bridge, detection circuit, classification circuit, dc/dc switch, hotswap switch, TVS overvoltage protection, dynamic soft-start circuit, cycle-by-cycle current limit, thermal shutdown, optional synchronous secondary rectification driver, automatic and user-mode MPS functionality, and inrush current protection. The isolated flyback converter outputs up to 1.05 A for a total power of 7 W while using a standard, off-the-shelf transformer. The Sifos IEEE compliance report, schematics, and layout, are all found in the User’s Guide.
It lists MSRP of $99.00 (£74.65).
There are links to reference manuals (LinkCom PC07xx-001R-A Transformer Second Source for Si3406-ISO-FB-EVB and LinkCom PF07xx-001LR Transformer Second Source for Si3406-ISO-FB-EVB), schematics and layouts, and user guide files.
The contents of the box is the same as SI3406FB12V2-KIT except the anti-static bag is labelled 'Si3406FB5V2-EB'.
The PCB is very similar to the one in the SI3406FB12V2-KIT (see the documentation for the differences in the hardware), however, the PCB label on the back of the PCB reads 'Si3406-ISO-FB-R4.2-5V'. Presumably the 'R4.2' refers to the board revision number and ‘5V’ the output voltage.
Schematics and Layouts file (Si3406FB5V2KIT.zip), downloadable from skyworksinc.com, contains the folders:
The bom folder contains SI3406-EVB-ISO-FB-5V-BOM.pdf Bill of materials for evaluation board SI3406-EVB-ISO-FB-5V. Doc dated 10/19/2022, revision 4.2.
The layout folder contains si3406-evb-iso-fb.pcb, si3406-evb-iso-fb-r4.2.zip, & si3406-evb-iso-fb-r4.2-asc.zip. Various PCB design software files.
The schematic folder contains SI3406-EVB-ISO-FB.dsn (compatible with various schematic design software) & SI3406-EVB-ISO-FB-5V-SCH.pdf (evaluation board SI3406-EVB-ISO-FB-5V schematic dated October 19, 2022).
Looking at the user guide, which is for multiple types of Si3406 based evaluation boards, and is dated December 22, 2022, page 1 gives an overview, I've reproduced some parts as follows:
The Si3406 isolated Flyback evaluation board is a reference design for a power supply in a Power over Ethernet (PoE) Powered Device (PD) application.
This Si3406-Flyback EVB provides simple and low-cost solution with different output voltages and power levels.
The Si3406 IC integrates an IEEE 802.3at compatible PoE interface as well as a current control-based dc/dc converter.
There is a table which confirms some keys specifications. One of the important ones:
PSE input voltage range 37 V to 57 V
Note: the guide says the input voltage connector is J1 but on the PCB the RJ45 socket is labelled U2.
And one in particular for SI3406FB5V2-KIT:
Output Voltage / Current 5 V / 1.05 A
On page 3 we can see that there are three evaluation board versions delivering 3.3 V, 5 V, and 12 V:
Si3406-ISO-FB-3.3V-7W – Class 2
Si3406-ISO-FB-5V-7W – Class 2
Si3406-ISO-FB-12V-7W – Class 2
Some further information from the guide:
The maximum input power allowed by the standard is 6.49W, but the EVB can handle up to 7W output power.
The boards are shipped with external silicon diode bridges installed but they are not connected. If higher efficiency is needed or >10 W capable XFMRs are validated with the dual footprint, the external silicon diodes (S1B) shall be connected by populating the JP1 and JP2 jumpers. Schottky diodes can be used too as external diode bridges, in this case SS2150 are recommended.
On the board, the internal diode bridges are used as rectifier bridges by default.
On to page 5, which describes powering up the board. As stated:
Power may be applied in the following ways:
Using any IEEE 802.3-2015-compliant, PoE-capable PSE, or
Using a laboratory power supply unit (PSU):
- Connecting a dc source between blue/white-blue and brown/white-brown of the Ethernet cable (either polarity, Endspan)
- Connecting a dc source between green/white-green and orange/white-orange of the Ethernet cable (either polarity, Midspan)
Diagrams are provided showing the wiring.
Pages 6 to 24 give detailed information about the 3.3 V evaluation board, pages 25 to 43 for the 5 V version, and pages 44 to 62 for the 12 V version. Moving on to page 63 it talks about the tunable switching frequency, page 64 has the board layout, page 67 the design and layout checklist, and lastly page 68 compatibility test reports.
Having gone through the user guide I moved on to trying out the evaluation board. As described on page 5 of the user guide we need to supply power to the board through the ethernet port. Fortunately I happened to have a tp-link Gigabit PoE injector TL-POE150S that I had been meaning to try out in a different project. The kit uses a 48 VDC 0.5 A mains power supply, which plugs into the injector's DC 48 V barrel jack connector. Since the evaluation board only concerns the power part of PoE I didn't need to connect anything to the injector's LAN IN ethernet port. I just had to connect an ethernet cable from the injector's POWER+DATA OUT port to the evaluation board's ethernet socket.
With everything connected I plugged the mains power supply into the mains and the PWR light on the injector lit and the green LED (D3) on the evaluation board lit after a brief delay. I measured 4.94V between J1 and J2 on the evaluation board with my multimeter without any load connected. Using my oscilloscope I measured it took approximately 3.46ms to go from 0V to 4.94V. I then used a power resistor across J1 and J2 to draw 1A and measured the voltage to be 4.89V.
All these readings seemed reasonable for the kit and was a good sign it was working as expected.
I couldn't find board dimensions stated anywhere but I measured the PCB to be 106.8mm x 38.4mm. Including the ethernet socket and power connector tabs that stick out from the PCB the total length is 116.6mm.
The product page can be found at:
https://www.skyworksinc.com/en/Products/Isolation/Evaluation-Kits/isolated-transceivers/Si85853-KIT
This is the description:
This evaluation kit is designed for quick and easy evaluation of the Si85853D 1 Mbps, 5.0 V, half duplex transceiver.
It lists MSRP of $60.00 (£44.89)
There is a link to the user guide, which is for various Si858x-EVB models.
Unsealing the box, inside was a card with SKYWORKS written on one side and on the other side:
Get started!
Find documentation and software at:
skyworksinc.com/ia/start-isolation
The link takes you to a page with a list of isolation evaluation kits.
The board was in a sealed anti-static bag with label 'Si85853-EVB', wrapped in anti-static bubble wrap. The board even with the internal packaging is much smaller than the box.
The PCB features a mounting hole in each corner with plastic standoff already attached. Toward the bottom long edge there is a sticker which has 'Si85853-EVB' written on it and to the right printed on the PCB 'SKYWORKS(R) Si858x-RS485-HDX-EVB REV 1.0' can be found.
The PCB features various connections, test points, and an Si85853 IC, the datasheet of which can be viewed at:
https://www.skyworksinc.com/-/media/SkyWorks/SL/documents/public/data-sheets/Si858x-DataSheet.pdf
All content of this and related pages is copyright (c) James S. 2026