Hello,

I am creating a small PoE powered device. I would like to use SI3404 because it have PD interface and DC/DC converter integrated.
I must achieve 3.3V 500 mA in output (1.65 W). Small dimensions is a key feature, so I'm looking for the smallest transformer possible.
The POE30P-33L form Coilcraft (3W, 310μH, leakage 4.75 μH, 1:0.19) seems to be an ideal part for my design. It has small dimensions and quite big inductance so the primary current peak would be small.
Can I use it with SI3404? What should be changed in the example design to get it work?

Hi we're developing a small product powered by PoE. Of the first three prototypes built the first worked right out of the box, the second worked for a second and then died with a puff of smoke. Thinking this was an exemplaric failure (hand build) I connected the third and that died after a second or so as well :(

The first one worked for a day, but has since then died, also releasing the "magic smoke" from the SI3402 (same symptom as the other two). I measured the 5 Volt power draw from the rest of the circuit and it is around 100mA, typically never above 200mA. When the first device worked I also noticed that the SI3402 (and the inductor, could not exactly tell) ran quite warm (I guess around 40-45°C) given the total power draw (but nothing excessively hot so it seemed).

As it is a low power device (1-2Watt) I'm solely using the internal rectifiers of the Si3402. The supply I'm testing with is a Ubiquity 48Volt/0.5Amp power injector.

It the SI3402 protected in any way? I.e. when an overcurrent is drawn will it shut down, of will it just blow (the internal rectifiers)?

Thanks for any help!

Schematics of the PoE supply (SP and CT terminals are connected directly to the RL45 jack/center taps):

Board layout attached (GND/Vneg plane not filled for clarity).

Hi,

I have two questions regarding the Si3404-ISO-FB EVB:

• Where can I find the design files?
• Is this recommended for new designs?

Best regards,

Erlend

Hi,

I'm trying to use the EM2 and EM3 energy using Simplicity Studio v4 in te Blue Gecko BGM13S32 Board. I followed this example:

https://docs.silabs.com/bluetooth/2.13/code-examples/applications/using-em3-or-em4-energy-mode-in-a-bluetooth-beacon-app

However, doing exactly the same, it doesn't work. Instead of getting a consumption in the order of uA, I get this:

I attach the here the project that I'm using.

The main purpose is to check the functionalty of the EM2 and EM3 modes in order to implement it in my own board with the bgm13s32 chip,  externally checking the energy profile through the Blue Gecko Board (Debug mode OUT). In this case, it also doesn't work when I use this in the main:

const gecko_configuration_t config =
{
  .sleep.flags = SLEEP_FLAGS_DEEP_SLEEP_ENABLE,

It reduces the energy but only in the order of mA. Should I add something else, or what I'm doing wrong?

Hi,

I'm trying to use the EM2 and EM3 energy using Simplicity Studio v4 in te Blue Gecko BGM13S32 Board. I followed this example:

https://docs.silabs.com/bluetooth/2.13/code-examples/applications/using-em3-or-em4-energy-mode-in-a-bluetooth-beacon-app

However, doing exactly the same, it doesn't work. Instead of getting a consumption in the order of uA, I get this:

I attach the here the project that I'm using.

The main purpose is to check the functionalty of the EM2 and EM3 modes in order to implement it in my own board with the bgm13s32 chip,  externally checking the energy profile through the Blue Gecko Board (Debug mode OUT). In this case, it also doesn't work when I use this in the main:

const gecko_configuration_t config =
{
  .sleep.flags = SLEEP_FLAGS_DEEP_SLEEP_ENABLE,

It reduces the energy but only in the order of mA. Should I add something else, or what I'm doing wrong?

Hi,

We would like to use Si3404 for one of our PoE application. I am referring to Si3404-ISO-FB EVB schematics and BOM. But, I am not able to get the datasheet of the transformer, TOEP13-0155S1 used in the design. Could you please send the datasheet of the transformer. Or is there any alternate Coilcraft or well known Transformer which can be used?

Thanks,

Shashank

Hi,

I designed a prototype board with POE using Si3402 for 5V output but its giving 12V instead. 

I would really appreciate if anyone can look at my attached schematics and figure out what I need to change.

Thank you

Hi,

I need to supply my electronic device with any PSE, so i have desinged my board with SI-3404 according to SI-3404-EVB board schematic (page-45). But when i connect my board to PSE, my SI-3404 board does not give any output (i wish that it gives 24V output when i plug it to PSE). My board schecmatic is below, so ,what is the difference between EVB board and my board? Any advises ?

It seems Si3404 is a new product, so many parameters are unclear. Can Silabs provide some more informations about the loop compensation design. Such as how much is the slope compensation in the chip? This information may be useful in the loop compensation calculations.

The transformer part numbers to change Si3402BISO eval board output voltage don't match the values given on coilcraft's homepage (refs: https://www.silabs.com/documents/public/user-guides/Si3402BISO-EVB.pdf and https://www.coilcraft.com/fa2805.cfm, https://www.coilcraft.com/fa2671.cfm)

They differ as follows:

I assume that the values mentioned by coilcraft are correct and the table in the user guide are somehow mixed up. But I would appreciate, if someone from SiLabs support team can confirm!

Thanks!

Hi everyone,

the datasheet says that the Si3454 can work in autonomous operation without using any processor.  So let us say AUTO-Pin is set to 1.54V. End span with 15.4W.
The PD which can be connected could be a Type 1 class 0 or class 3.

1. What happens when a type 2 PD will be connected?

2. What happens when a type 1 class 1/2 PD will be connected?

For both cases, will the controller went shutdown?
For case 2: Will the controller provide the power?
Is there any signal which can be used as a trigger to reset the system?

Kind regards

I am designing a HAT for RockPi-E and I need to implement the PoE part. I decided to use a SI3404 and I'm selecting the transformer to use in the design.

Looking on forum and documentation, those two parts have been recommended: TOEP13-0155S1 and 749119950. Unfortunately the first one is hard to source and the second one is quite expensive.

I found another part from Coilcraft, more easy to source and cheaper than WE one: POE13P-50

From the datasheet it looks very similar to WE part, I suppose it will work but I'd like to ask for confirmation before proceeding with my design.

My idea is to implement the schematic from this document, copying everything except the transformer. 

thanks in advance for your help

Dario

Hi,

though the Si3404 is on the market for a while now, documentation is still scarce. 

We are looking for a PoE solution using 802.1at Type 1 very close at maximum power, so high efficiency is a must. Therefore I have 2 questions:

• at 12 V output voltage, what efficiency gain can be expected from replacing Si3402-C with Si3404?
• What changes to Si3404-ISO-FB EVB are necessary to get 12 V output voltage?

Thanks a lot!