Datasheet

Table 23-26. 10BASE-T Transmitter Characteristics (continued)
UnitMaxNomMinParameter Name
ns-300
350
-Start-of-idle pulse width
a. The Manchester-encoded data pulses, the link pulse and the start-of-idle pulse are tested against the templates and using
the procedures found in Clause 14 of IEEE 802.3.
Table 23-27. 10BASE-T Transmitter Characteristics (informative)
a
UnitMaxNomMinParameter Name
dB--15Output return loss
dB--29-17log(f/10)Output impedance balance
mV50--Peak common-mode output voltage
mV100--Common-mode rejection
ns1--Common-mode rejection jitter
a. The specifications in this table are included for information only. They are mainly a function of the external transformer
and termination resistors used for measurements.
Table 23-28. 10BASE-T Receiver Characteristics
UnitMaxNomMinParameter Name
ns--30Jitter tolerance (pk-pk)
mVppd700600500Input squelched threshold
kΩ-20-Differential input resistance
V--25Common-mode rejection
Table 23-29. Isolation Transformers
a
ConditionValueName
+/- 5%1 CT : 1 CTTurns ratio
@ 10 mV, 10 kHz350 uH (min)Open-circuit inductance
@ 1 MHz (min)0.40 uH (max)Leakage inductance
25 pF (max)Inter-winding capacitance
0.9 Ohm (max)DC resistance
0-65 MHz0.4 dB (typ)Insertion loss
Vrms1500HIPOT
a. Two simple 1:1 isolation transformers are required at the line interface. Transformers with integrated common-mode
chokes are recommended for exceeding FCC requirements. This table gives the recommended line transformer
characteristics.
Note: The 100Base-TX amplitude specifications assume a transformer loss of 0.4 dB. For the
transmit line transformer with higher insertion losses, up to 1.2 dB of insertion loss can be
compensated by selecting the appropriate setting in the Transmit Amplitude Selection (TXO)
bits in the MR19 register.
Table 23-30. Ethernet Reference Crystal
a
ConditionValueName
MHz25.00000Frequency
PPM±50Frequency tolerance
763June 18, 2012
Texas Instruments-Production Data
Stellaris
®
LM3S8962 Microcontroller
NRND: Not recommended for new designs.