AnsweredAssumed Answered

Output voltage problem with ST802RT1A

Question asked by cen.jinkang on Sep 18, 2012
Latest reply on Sep 21, 2012 by cen.jinkang
Hi there

I am using the Ethernet Transceiver ST802RT1A to make my own PCB board following the design of STEVAL-PCC012V1 (http://www.st.com/internet/evalboard/product/250577.jsp) except one thing - I changed the magnetic RJ45 from Pulse J00-0086 to another one with a turn ratio of 1:1. But now a problem occurs that the computer cannot setup a communication with the board I made.

When I run the sample Hello World program, I see the transceiver is transmitting some information from the oscilloscope. But the computer cannot receive anything from the transceiver when sniffing with Wireshark. The output voltage level of TD+ and TD- is from -0.7V to +0.7V. I am wondering if it is too low for the computer to detect??? Is it necessary to use a magnetic jack with a turn ratio of 1.414:1 instead??

Thank you!

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