LM3S8938 Datasheet, PDF (517/550 Pages) List of Unclassifed Manufacturers – Microcontroller

LM3S8938 Microcontroller
Parameter Name
Start-of-idle pulse width
Min Nom Max Unit
- 300 - ns
350
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 22-17. 10BASE-T Transmitter Characteristics (informative)^a
Parameter Name
Min
Nom Max Unit
Output return loss
15
- - dB
Output impedance balance
29-17log(f/10) - - dB
Peak common-mode output voltage
-
- 50 mV
Common-mode rejection
-
- 100 mV
Common-mode rejection jitter
-
- 1 ns
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 22-18. 10BASE-T Receiver Characteristics
Parameter Name
Min Nom Max Unit
DLL phase acquisition time - 10 - BT
Jitter tolerance (pk-pk)
30 - - ns
Input squelched threshold 500 600 700 mVppd
Input unsquelched threshold 275 350 425 mVppd
Differential input resistance - 20 - kΩ
Bit error ratio
- 10^-10 -
-
Common-mode rejection 25 - - V
Table 22-19. Isolation Transformers^a
Name
Value
Condition
Turns ratio
1 CT : 1 CT
+/- 5%
Open-circuit inductance 350 uH (min) @ 10 mV, 10 kHz
Leakage inductance
0.40 uH (max) @ 1 MHz (min)
Inter-winding capacitance 25 pF (max)
DC resistance
0.9 Ohm (max)
Insertion loss
0.4 dB (typ)
0-65 MHz
HIPOT
1500
Vrms
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.
June 14, 2007
517
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