Chapter 2
Specifications and Requirements
Electrical specifications are outlined in the IEEE 802.3 document. These values listed below are based upon the Draft supplement to IEEE Std. 802.3 Type 10BaseT issued on June 28,1990. A more current revision should be researched to get the most current specification data.
Electrical:
The Transmit transformer secondary winding minimum inductance is 350uh with 8ma. DC bias applied over 0o to +70oC.
This inductance is needed to meet the waveform templates specified in 802.3.
There shall be 1500 VRMS isolation between the input and output of the transformer.
The rise time and fall time shall be between 3 and 5ns.
There shall be no more than 5% overshoot
The insertion loss shall be less than –1.0db between 1 to 100Mhz
The return loss shall be greater than –15db over the frequency range of 5MHz to 10MHz with a resistive source of between 85 ohms to 111 ohms.
The typical crosstalk between 1Mhz to 10Mhz should be better than –40db.
The typical Common Mode Rejection between 1Mhz to 50Mhz should be better than –30db.