I am using the SI3402 chip to use POE.
But it does not work properly.
The circuit I have constructed is as follows.
POE: SI3402 (non-isolated)
Ethernet Transceiver: H2019NL
When POE cable is plugged in, it charges for the first time but it becomes impossible to charge soon. I think that the POE side circuit is a problem because I operate normally when only 5V is applied to the charge IC.
Since it is confirmed that 5V is output from the output terminal, it is not a voltage problem.
I attach the schematic that I composed with PDF.
Please make sure that there is something strange in my circuit.
I am using the SI3402-B chip to use POE（isolate）.
But it does not work when loading exceed 5V/1.3A.
When I remove the tvs diode of the Transformer primary，it can work at 5V/3A, what is the reason of this phenomenon？
We have an isolated PoE PD test board with an Si3402-B on board, using a Coilcraft FA2732 transformer to create an isolated +12V at the output.
Class detection works fine, but when starting the PSE, the output ramps to approx. 8V and then it aborts; the PSE reports OVL.
Do you see any obvious issue in the enclosed schematics? Can the opto-coupler have a significant influence on the boot-up process?
Thanks for your help.
We are testing a DC-DC converter and the gate driver is Si8233BD. A 50kHz, 3.3V PWM is generated from the TI28377S launchpad (DSP) and is given to the driver IC (VIA, VIB). We are getting the VOA output pulses, but the VOB is always clamped to high. Please find the attached schematics. Could you please help us to resolve the issue.
What is the difference between Si8655BA-B-IU and Si8655BA-C-IU
If it's in the datasheet , I really can't see it.
Extra credit: Why is the small-pitch package called a "QSOP?" I expected pins on four sides.
I am using a SiLabs 864x digital isolator ( with no enable pins and no pre-determined output levels). Both sides are powered with 3.3V/GND, but the supplies are separate. When the 3.3V supply is off, my digital inputs can still be active. Since the supply is off on both sides, as expected, my input signals do not propagate. However, I am measuring voltage at the supply pin on the input side. This appears to be back-fed from the input signals.
Given that some input signals are at logic high before powering up the input and output supply voltages to 3.3V, intermittently I have seen failures in propagating the inputs to the outputs. That is, after powering both sides to 3.3V, an input may be at a logic high, but the corresponding output pin is stuck at a logic low.
These devices have a lockout feature for supply voltages below a given threshold, but it appears that the lockout continues even though the voltages are above the threshold. The only reliable way to resume normal communication is to force the inputs (disconnect) to a logic zero and then cycle the input side supply voltage (off and back to on). Followed by re-connecting a cable that feeds the inputs.
My questions are: Is it required that all inputs are at a logic zero prior to supplying power to the input side? If this is true, would a tristate condition work as well? Is there a reason why the outputs would not follow the inputs when both supplies are powered?
Now, I meet a question. when Si8273GB is used, its output voltage is 2.47V. why? I want to get 6V. I want to know if the Si8273 get 6V output voltage.
when i used si827x to driving GaN device, the driving waveform shows that source ability does not meet the IOH spec. at 0ns ~ 5ns.
I hope siliconlab can provide the transient ability curve. That will be great if can provide Spice model (only the driving part).
As per truth table in datasheet Si827x(Page No:12),The state of Voa and Vob are mentioned in the condition of VDDA and VDDB powered.
If VDDA and VDDB are unpowered during start up,what would be the state of Voa and Vob?
I am using SI8602AC-B in our design for isolating I2C signals.
SCL is unidirectional and SDA is bidirectional.
Design flow is like ADC-> SI8602AC -> MCU(ATSAME54)
ADC supply voltage is 5V and MCU is 3.3V
1. Does SI8602 can act as a voltage level translator that convert 5V I2C to 3.3V I2C?
2. Can BVDD and AVDD be different?
Attached snippet of my SCH.
Please respond... Thanks