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:
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 function.
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 standoffs 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).
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.
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 here:
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.
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 standoffs 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
I couldn't find the board dimensions stated in the user guide but I measured the PCB to be 63mm x 123mm.
On page 1 of the user guide it gives an overview of which the key part is:
The board provides the MCU host interface and RS-485 cable interface to connect the Si858x transceiver to the RS-485 bus/network.
Key features are also listed:
Si858x isolated RS-485 transceiver
Compliance to TIA/EIA-485-A (RS-485) and EN 50170 (ProfiBus)
5 kVrms safety rated isolation
Up to 10 Mbps data rate
RS-485 bus signal slew rate control (on 1 Mbps data rate device)
Onboard optional 120 Ω ac termination
100 kV/µs common mode transient immunity (CMTI) performance
128/256 Unit Load (UL) support
Half/full duplex communication
Flexible isolated power supplies
Reverse polarity protection for input supplies
Page 3 has the block diagram and illustration of typical interface setup and on page 4 has information about identifying EVB Ordering Part Number (OPN). The main information is:
There are two major types of Si858x EVBs: full-duplex (FDX) and half-duplex (HDX). The full-duplex EVB supports the separate differential pairs for bus signal transmission and reception. By contrast, the half-duplex EVB uses the same differential pair for bus signal transmission and reception. Each type of EVB also includes several board variants based on the Si858x chip being populated on the EVB. The label on the PCB can be used to identify the exact board variant, as shown in the following figure.
Looking at the EVB Label table, SI85853-EVB has following features:
Si858x Part Number RS-485 Configuration Nodes Slew Rate Control/Data Rate VDD1 VDD2
Si85853D-IS Half Duplex 256 Yes / 1 Mbps 3 ~ 5.5 V 5 V
Pages 5 to 6 are dedicated to connectors, LEDs, and jumper settings, and page page 7 deals with powering up the EVB, in which it is stated:
Two isolated voltage power supplies for VDD1 and VDD2, respectively, are required to power up the Si858x EVB.
Other pages that may be of particular interest include pages 14 and 15, which have the schematics and Bill of Materials (BOM) respectively for the Si858x-HDX-EVB, and pages 16 and 17, which have the schematics and BOM respectively for the Si858x-FDX-EVB.
Note: presumably HDX=half duplex, FDX=full duplex.
For testing I used loopback mode, as that was the easiest way and since the device was sealed I didn't need to do too thorough testing.
As detailed in the user guide pg 11:
As long as the EVB is detached to other RS-485 node, no special treatment is necessary to get the loop-back data. Because of that, we can simply use the function generator to provide the data on Tx pin of J5 to run the loopback test while Tx_EN = HIGH and Rx_ENb = LOW. Please also check Table 3.3 Si858x EVB Jumper Settings on page 6 for the jumper short positions on P2 and P3 for Tx_EN and Rx_ENb signals.
So I connected separate USB 5V power supplies to J3 and J4 respectively and I connected a square wave signal generator set to 5KHz to TX (pin 4) and GND1 (pin 5) of J5, powered off one of the USB power supplies. I connected an oscilloscope CH1 to TX of J5 and CH2 to RX (pin 1) of J5, both oscilloscope channel grounds wired to GND1.
There was already a jumper on P2 holding TX_EN to VDD1 and a jumper on P3 holding Rx_ENb to GND1 so those jumpers were already set up appropriately. No other jumpers needed to be changed.
I observed that RX replicated TX exactly, with minimal lag of RX from TX.
I also checked the A (pin 5) and B (pin 4) signals of J2, using CH1 and CH2 of my oscilloscope, both oscilloscope channel grounds wired to GND2. CH1 and CH2 as expected were an inverted version of each other. Also, A was the same as the signal fed into TX and B the inverted version, which matched what was shown in the user guide.
Note that if the oscilloscope probe connector grounds are internally connected (which usually is the case) and you connect the oscilloscope probes to both sides of the board using both GND1 and GND2 then both grounds will be shorted together, defeating the isolation provided by the evaluation board's chip but of course for simple testing this is OK. Using two oscilloscopes or isolated probes would be a better option. Additionally, I had to connect the signal generator to the power supply powering VDD1 rather than VDD2 otherwise the signal on the A and B pins appeared as brief pulses. Ideally the signal generator would be run off a separate power supply.
Next, current consumption measurement. The jumper on JP10 and JP9 needed to be removed so that the 1R shunt resistors on VDD1 and VDD2 respectively (R21 and R22) were no longer bypassed. A multimeter can then be used to measure the voltage across each resistor, which can be done most easily be measuring across JP10 and JP9 respectively.
We can easily work out the current draw by the main circuit (not including the LED, limiting resistor and MOSFET at the input power stage) from the voltage across the shunt resistor, which is 1R.
Note that VDD1 measured 5.05V to GND, VDD2 measured 5.03V to GND.
With just JP10 jumper removed I measured 2.6mV across JP10, which equates to 2.6mA.
With just JP9 jumper removed I measured 11.7mV across JP9, which equates to 11.7mA.
These both seem reasonable values according to the Si85853 datasheet.
I did also measure the current going into J3 with JP10 jumper only removed: 10.36mA.
Also, the current going into J4 with JP9 jumper only removed: 19.37mA.
These two measurements are for the total current used by the circuit including the LED, limiting resistor and MOSFET at the input power stage.
The product page can be found at:
https://www.skyworksinc.com/en/Products/Isolation/Evaluation-Kits/isolated-transceivers/Si85855-KIT
This is the description:
This evaluation kit is designed for quick and easy evaluation of the Si85855D 10 Mbps, 5.0 V, half duplex transceiver.
It lists MSRP of $60.00 (£44.89).
There is a link to the user guide.
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 'Si85855-EVB', the board is much smaller than the box.
The PCB has a mounting hole in each corner with plastic standoffs already attached. Toward the bottom long edge it has a sticker with 'Si85855-EVB' written on it and to the right printed on the PCB is 'SKYWORKS(R) Si858x-RS485-HDX-EVB REV 1.0'.
The PCB is similar to the one in SI85853-KIT (see the relevant section on this page), featuring various connections and test points, but having utilising the Si85855 IC, the datasheet of which can be viewed at:
https://www.skyworksinc.com/-/media/SkyWorks/SL/documents/public/data-sheets/Si858x-DataSheet.pdf
The user guide for the SI85855-KIT is the same as for the SI85853-KIT.
I couldn't find the board dimensions stated in the user guide but I measured the PCB to be 63mm x 123mm, the same as the SI85853-KIT.
Looking at the EVB Label table on page 4 of the user guide, the Si85855-EVB has the following features:
Si858x Part Number RS-485 Configuration Nodes Slew Rate Control/Data Rate VDD1 VDD2
Si85855D-IS Half Duplex 256 No / 10 Mbps 3 ~ 5.5 V 5 V
The main difference compared to the SI85853-KIT is that the Si85855 doesn't have slew rate control but it does have a higher data rate of 10 Mbps compared to SI85853's 1 Mbps.
For testing, I used loopback mode as I did when testing the SI85853-KIT, which produced the expected results.
I also did the same current consumption measurements as with SI85853-KIT, here are the results:
JP10 removed: 2.6mV.
JP9 removed: 11.2mV.
Current through JP10: 10.03mA.
Current through JP9: 17.74mA.
Note that VDD1 measured 5.05V to GND, VDD2 measured 5.03V to GND.
The product page can be found at:
https://www.skyworksinc.com/en/Products/Isolation/Evaluation-Kits/isolated-transceivers/Si85857-KIT
This is the description:
This evaluation kit is designed for quick and easy evaluation of the Si85857D 1 Mbps, 5.0 V, full duplex transceiver.
It lists MSRP of $60.00 (£44.89)
There is a link to the user guide.
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 'Si85857-EVB'', the board is much smaller than the box.
The PCB has a mounting hole in each corner with plastic standoffs already attached. Toward the bottom long edge there is a sticker with 'Si85857-EVB' written on it and to the right printed on the PCB it has printed 'SKYWORKS(R) Si858x-RS485-FDX-EVB REV 1.0'.
The PCB has various connections and test points, and features the Si85857 IC, the datasheet of which can be found at:
https://www.skyworksinc.com/-/media/SkyWorks/SL/documents/public/data-sheets/Si858x-DataSheet.pdf
Although the PCB is similar to the Si858x-RS485-HDX-EVB it has more components since it features full duplex rather than half duplex chip.
The user guide for the SI85857-KIT is the same as for the SI85853-KIT, which I’ve already covered - please see that section on this page for more information.
I couldn't find the board dimensions stated in the user guide but I measured the PCB to be 63mm x 123mm, the same as the SI85853-KIT.
Looking at the EVB Label table on page 4 of the user guide, Si85857-EVB has the following features:
Si858x Part Number RS-485 Configuration Nodes Slew Rate Control/Data Rate VDD1 VDD2
Si85857D-IS Full Duplex 256 Yes / 1 Mbps 3 ~ 5.5 V 5 V
For testing I used loopback mode as described on page 11 of the user guide just as I did when testing the SI85853-KIT so I won’t go into full detail here other than to mention any differences. In addition to the setup I used with the SI85853-KIT, to test SI85857-KIT, J2 A (pin 5) needs to be wired to Y (pin 2) and J2 Z (pin 3) wired to B (pin 4).
I connected oscilloscope CH1 to TX (where the signal is fed in) and CH2 to RX, with oscilloscope grounds to GND1, I observed that CH2 showed a copy of CH1 with slight lag, as expected. With oscilloscope CH3 connected to A/Y and CH4 connected to B/Z, with oscilloscope grounds to GND2, CH3 showed the same signal as CH2 (RX) and CH4 showed an inverted version of CH2, which matched what was shown in the user guide.
Note: if the oscilloscope probe connector grounds are internally connected, GND1 and GND2 will be shorted, defeating the isolation provided by the evaluation board's chip but for simple testing this is OK.
Next, I did the same current consumption measurements as with the SI85853-KIT.
JP10 removed: 2.6mV.
JP9 removed: 11.4mV.
Current through JP10: 10.66mA.
Current through JP9: 19.22mA.
Note that VDD1 measured 5.05V to GND, VDD2 measured 5.03V to GND.
The product page can be found at:
https://www.skyworksinc.com/en/Products/Isolation/Evaluation-Kits/digital-isolator/Si86SSxx-KIT
This is the description:
The Si86SSxx isolator evaluation kit includes devices that are specially designed to support SPI and QSPI bus isolation in WB SOIC-16 or QSOP-16 package options. This EVB is intended to simplify basic functional testing and engineering validation of these bus isolators.
It lists MSRP of $60.00 (£44.89).
There is a link to the user guide and the design package which includes BOM, layout, schematic and a copy of the user guide.
Unsealing the box, inside was 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 'Si86SSXX-EVB'', the board is about quarter the size of the box, a waste of space but it was probably cheaper to use one size box for each product. Additionally, as with the other kits, since I had multiples I can store more than one in a box, allowing me to cut down on the number of boxes.
The PCB has a mounting hole in each corner with plastic standoffs already attached. Toward the top of the PCB it has written 'SILICON LABS SiLabs(R) Si86SSxx-EVB REV 2.0'. This is interesting as Silicon Labs sold its Infrastructure & automotive business to Skyworks in 2021.
The PCB is divided into four parts, the top part contains the power supply related circuitry, and the other three parts are for the Si86SS41BE-IS2, Si86SQ44BE-IS2, and Si86SQ44EB-IU accordingly. The datasheet for the chips can be found at:
https://www.skyworksinc.com/-/media/SkyWorks/SL/documents/public/data-sheets/si86s6xx-datasheet.pdf
The user guide, which is dated 2022, gives an overview of the kit on page 1, and page details the required equipment of which I’ve listed the main ones:
Si86SSxx-EVB Rev 2.0
Two 5 V power supplies
Two DMMs in current mode
0 V to +5 V signal source, up to 150 Mbps or 75 MHz capable, 50% duty cycle (the standard isolator devices can toggle at up to 150 Mbps rate; the signal source/oscillator need not be that fast.)
Oscilloscope
For the power supplies I used two phone chargers I happened to have, one rated 5V 1A, the other 5V 2.1A, I would imagine you can use much lower current power supplies. Of course this is not the best setup and the power supplies aren't necessarily separated just because they are two physical power supplies but for simple testing will suffice.
Page 4 talks about the test setup. This is what I did: I connected both power supplies with a DMM in current mode on one of the power supplies only (the one connected to J1), it read just 9.08mA. Removing the JP3 jumper, which turned off LED D2, the current reading dropped to 8.75mA. It’s not surprising turning off the LED caused such little current drop as looking at schematic the LEDs have a series 10K resistor. With jumper removed the JP3 header can be used to measure LED current which, not surprisingly, was 0.33mA. The same applies to the other LED and the corresponding jumper.
Page 5 details digital isolator considerations and page 6 has the Si86SS41BE-IS2 (U1 Device) Setup and Demo Test.
For testing Si86SS41BE-IS2 (and the other chips on the board) I used a simple signal generator (which I powered off the power supply feeding one side of the board) producing a 5V square wave (50% duty cycle) and an oscilloscope. I connected the GND of J1 and J2 together since I used a single oscilloscope.
Although the Si86SS41BE-IS2 is designed for isolating SPI digital signals it also works for other digital protocols but for simple testing a square wave can be used. The chip supports up to 75 MHz 50% duty cycle but I kept to 5 KHz. Of course you don't even have to use a signal generator, you could just take an input high or low and observe the results. The point of using a signal generator is to see how fast the chip reacts to high speed signals - which is what would typically be used with these types of chips, and how accurate the output signal is compared to the input.
To test, I connected the signal generator to an input pin of the Si86SS41BE-IS2 and connected oscilloscope CH1 to the same pin, and oscilloscope CH2 connected to Si86SS41BE-IS2 corresponding output pin. I observed that both signals were identical with very minimal lag of output compared to input (datasheet specifies typical 10ns propagation delay).
Here is a summary of the inputs and outputs:
Input Output
/MCS /SCS
MCLK SCLK
MMOSI SMOSI
SMISO MMISO
Note that there will only be a signal at MMISO when /MCS is low as otherwise the buffer will be disabled.
Page 7 deals with the Si86SQ44BE-IS2 (U3 Device) Setup and Demo Test.
As with Si86SS41BE-IS2, for testing Si86SQ44BE-IS2 I used a signal generator and an oscilloscope. Si86SQ44BE-IS2 is different in that it has four isolated bidirectional channels (A1 to A4/B1 to B4), the direction controlled by the DIR_IN pin. When DIR_IN high, signal flows Ax to Bx. When DIR_IN low, signal flows Bx to Ax. DIR_OUT is an isolated version of DIR_IN. There are also enable pins, EN_A and EN_B: EN_A/EN_B when high enables the corresponding section's output buffers, when low sets to tristate. EN_A and EN_B have pull-up resistors.
Page 8 has the Si86SQ44EB-IU (U4 Device) Setup and Demo Test.
Note that Si86SQ44EB-IU is functionally the same as Si86SQ44BE-IS2, but they have a different chip package and electrical ratings, please see the relevant part of the datasheet for exact details. The chips also have a different default output state:
Si86SQ44EB-IU: Configured with a High default output state
Si86SQ44BE-IS2: Configured with a Low default output state
This is of concern when the output buffers are disabled using the EN pin.
Lastly, page 9 has additional board features relating to power circuitry, page 10 BOM (Bill of Materials), page 13 schematics, and page 16 layout.
On page 15 of Si86SSxx-EVB.pdf in the design package it specifies the board measures 4.110" x 2.80", which translates to 104.39mm x 71.12mm, which I’ve confirmed is correct.
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