W5500 Fails at -20 Degree Celcuis

Question

Hi, I am using W5500 in one of my product and recently tested its negative temperature. Below -20 deg cel the W5500 stoped working despite its datasheet mentions working capability of upto -40 deg cel. I need guidance from Wiznet community, otherwise i have no option but to switch to another ethernet IC. Thanks.

Eugeny · Answer

How it fails? How it stops working? Any diagnostic information? Edit: circuit has some more components than W5500, maybe something else is a cause, for example crystal?

salik satti · Answer

Hello, We are also having same issue where W5500 stops working at Below -20 deg cel. We have bypassed the W5500 IC and used W5500 Ethernet Network Module with Arduino MKR Zero ATSAMD21G18A. We have one LCD interfaced with MKR Zero at temp below -20 LCD is working, that means controller is alive and working but we cannot access the ethernet on both W5500 IC and W5500 Ethernet Module.

Raza Parvi · Answer

Hi Eugeny, 1: “Is there any technical information available - did you check error codes for application or states of W5500 which may give an idea why it does not work and how it does not work?” Currently we are using the Arduino library of w5500 (https://github.com/PaulStoffregen/Ethernet). First we check the W5000 IC status and later the link status using the following functions. // Checking whether the Ethernet shield (W5500) is responding or not. if (Ethernet.hardwareStatus() == EthernetNoHardware) { display_string(“No Ethernet shield”,0,S_row3 ,RED,BLACK); } //This code is checking whether the Ethernet cable is connected or not. if (Ethernet.linkStatus() == LinkOFF) { display_string(“No Ethernet Cable”,0,S_row3 ,RED,BLACK); } 2: “Did you try to heat W5500 to prove that it is the real case for the issue, and not a magnetics or cable?” Let me elaborate our testing and troubleshooting of this issue further: 1: Initially, we had our own custom board with an ATSAMD21 controller and Wiznet5500 and the board ethernet worked perfectly at normal temperature. When the hardware (enclosed in a chassis) was tested for negative temperature in a chamber at -30 degree the ethernet did not respond and there was error “No Ethernet shield”. It only started working when the temperature reached around -18 degrees. We checked all components’ temperature ratings but the problem is still there. 2: In 2nd approach we bypassed the onboard wiznet w5500 ic and used W5500 Arduino ethernet shield with our board microcontroller and tested in the Temperature chamber. The ethernet failed again showing error of “No Ethernet Shield”. If it were to be the problem of Magnetics or cable the Arduino Ethernet Shield would have worked. here is our own schematic: image.png821×866 47.9 KB

Eugeny · Answer

Library calls getchip which is most probably getting here, I may propose you to modify libraries adding diagnostic messages on each command to see what it returns and where it fails. It may give an idea why it fails. Edit: one of the points of failure can be reset line. What part numbers do you use for capacitors? Derate them appropriately at -20 C and check the curve - is reset timing still withing spec? Do you perform hardware reset if the chip in your software suing RST pin? Second point is oscillator circuit, is it functioning at -20 C?

salik satti · Answer

Hello, Yes the Oscillator circuit is well within tested ranges and operates fine at required temperatures. We have tested again using RST pin and perform hardware reset doesn’t helped us either. So finally we have decided to go for some other vendor for -ve temps. Thanks.