W5500 SPI not response

Question

Hi there, I have integrated the W5500 into my own circuit with an ESP32 microcontroller. I have largely adopted the circuit from the Wiki. Now I have the problem that the chip on the finished PCB does not respond to requests on the SPI bus. I suspect there is still a problem with the circuit, but I have no idea where to look. At the moment I’m not sure whether I have used the correct inductor. Can someone give me some help? reference: http://wizwiki.net/wiki/doku.php/products:w5500:refschematic w55001271×872 69.7 KB

agent47 · Answer

In the meantime I have replaced the L1 with a ferrite with 120 ohms at 100 MHz (BLM21PG121SN1D). But that didn’t help. In my circuit diagram, the yellow LED is also connected the wrong way round, but that shouldn’t be a problem for the time being. When I plug in a network cable, the green LED flashes irregularly. So, at least on the network connection side, everything seems to fit. At the VBG pin (18) I can also measure the 1.2V which should also be present according to the data sheet. I still have the problem that I don’t get any answers from the W5500 chip on the SPI bus. Does nobody have an idea why that could be?

agent47 · Answer

The network part works. The connection to the mcu is ok (all traces are connected).