W5500 Crystal Frequency Question

Question

Hi, we have a product which uses W5500 as the Ethernet controller. But we are running out of stock of the crystal that connects to pin 30 and 31. We see from the datasheet that the requirement for the crystal is 25MHz. Can we use some other frequency like 24MHz (lower) or 30MHz (higher)?

bruno · Answer

hi Use of other frequencies is not guaranteed. The W5500 Ethernet controller is designed to work with a 25 MHz crystal for its Ethernet PHY to operate correctly. Using a crystal with a different frequency can lead to the PHY not operating within its specified parameters, which can cause unreliable operation or even a failure to function.

jwyoungster · Answer

Question related to the 5500 crystal… I am using an ECS -1637B2 2mmx1.6mm crystal. 18pf load capacitance, drive level of 100uW max. I know the layout is good…having issues with the 5500 even starting up… is this part “good enough” ? i.e. drive level?..(i know all the other parameters are good to go…-30to85C, +/-10ppm freq tol, freq stab…)…I have 27pF caps as the "load capacitors (C1=C2 = (Cload-Cstray)*2…assume Cstray 4pF…Cload=18pF…puts us at C1=C2 ~ 27pF… ??? any thoughts…?anyone?

Eugeny · Answer

jwyoungster: will the 5500 “LINK” if there is an ethernet cable plugged into it Yes. jwyoungster: I’m holding the reset line LOW for at least 100mS after 3.3VDC stabilizes… Info is in datasheet. Check power supply (supply of the power) during startup and operation.