W6100 is dead. Is there a problem with the circuit I made?

Question

Hello. I am making and testing a communication board using Wiznet W6100. I am using it with 3.3V voltage, but the board is broken. When I took pictures with a thermal imaging camera, it appears that the W6100 chip is broken. If there is a problem with my circuit design, please let me know. image1237×816 171 KB

miarossi · Answer

Hi, You can try the following troubleshoot to fix the issue with your Wiznet W6100 communication board. Power Supply and Decoupling Capacitors- Ensure that the power supply to the W6100 is stable and clean. The decoupling capacitors (C37, C39, C42, C43, C44, C45, C46) should be placed as close as possible to the power pins of the W6100 to filter out any noise. Thermal Management: You also need to verify that the W6100 chip is adequately cooled. Excessive heat could indicate an issue with power supply regulation or short circuits. Power Pin Connections can also be the reason so you must double-check all power pin connections (3.3V and GND) to ensure they are correctly routed and that there are no shorts or incorrect connections. You can also check this GitHub - jsyk/x65: The 65c02 and 65c816s-based modern retro computer devops tutorial Examine the signal lines (ETH_TXP, ETH_TXN, ETH_RXP, ETH_RXN) to ensure they are properly terminated and there are no reflections or excessive noise. Proper impedance matching is crucial. Verify the values of resistors and capacitors, especially those directly connected to the W6100, to ensure they are as per the recommended values in the W6100 datasheet. Check the configuration pins (MOD0, MOD1, MOD2) to ensure they are set correctly for your desired operation mode. If these checks do not resolve the issue, consider re-evaluating the PCB layout for potential design flaws that might affect the operation of the W6100. Additionally, reviewing the W6100 datasheet and reference designs might provide further insights into any specific requirements or considerations for reliable operation. Thanks

Eugeny · Answer

hqkwon1114: When I took pictures with a thermal imaging camera, it appears that the W6100 chip is broken What is the reason you decided so? Proofs? Thermal picture with legend? Edit: simulate the pi filter circuits at various power level rise speeds. You will see the design, especially the one you have made for 1V2 putting two pi filters in series, if going resonant, will kill the circuit.

Eugeny · Answer

hqkwon1114: my communication board started to require more than 3 times the usual current, What current it requires now? What is usual current? How do you measure this current? hqkwon1114: I looked at it with a thermal imaging camera, only the Wiznet chip was hot How much it was hot? hqkwon1114: why I decided that the Wiznet chip was dead All your explanations do not mean chip is “dead” unless you say it does not operate any more as expected.