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7.2.15 AUI Collision Specifications

7.2.16 Network Test Loads

Note: The 40

Ω load is the effective differential resistance seen by the TXU pins during normal operation. P lease see Figure6 which shows a 1:

2transformer

for the TXU pins. Since a 100

Ω load on the other side of a 1:2 transformer looks like a 25Ω load to the TXU side of the transformer, the equivalent differential

resistance seen by the transmitting

port is = 10.5//Zc + 25 + 10.5//Zc ~= 40

Ω where Zc is the impedance of the 1000 pf capacitors. For 10BASE-T

frequencies between 5 MHz and 10 MHz this impedance varies between 32 to 16

Ω in // with the 10.5 Ω resistors.

7.2.17 AC Timing Test Condition

Symbol

Parameter

Min

Max

Units

Collision Turn On Delay (CD

± to COL)

600

ns

Collision Turn Off Delay (CD

± to COL)

900

ns

Figure 15. Attachment Unit Interface Load for ATE testing

Figure 16. Twisted Pair Interface Load for ATE testing

Reference

Limits

0 V - 3.0 V

Input/Output Reference Levels (Digital Pins)

1.5 V

Differential Input Reference Levels

2.0 Vpp

Differential Input/Output Reference Levels

50% of Differential

CD±

COL

27 uH

78

Ω

TX+

TX-

TX OutputTest Load

Ω

TXU+

TXU-