I'm having an odd issue and I was hoping someone here might be able to help me out. I believe I'm having some thermal issues and I was hoping to get some sort of confirmation here before I start carving up my board.
I'm working with an ENC28J60 Ethernet Controller. It's a basic SPI Ethernet controller by Microchip. Now, I'm getting some repeated results in which when the board heats up after a while I'm loosing my UDP connection. After I let everything cool down overnight, everything works without a hitch again. I skirted some requirements a bit due to success I was having on my dev board. It's a 3v3 device, but the input pins are 5V tolerant. Having it plugged straight to my PIC's SPI bus allowed everything to go off without a hitch.
I'm thinking that it's the connection between the ENC28J60 and my microcontroller (PIC18F4680) because the Ethernet chip seems to be working fine. I'm getting the correct status LEDs on my RJ45 connector and the PIC seems to be going on it's way normally, it just isn't communicating with the Ethernet chip anymore.
The PIC handles the 3v3 signal from the ENC fine under normal conditions, but it seems like I will need to hack in a level shifter to get it working in all conditions. Does this sound plausible to anyone else, or do you guys think I should be looking elsewhere?
ENC28J60
http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en022889