78Q2120C
10/100BASE-TX
Transceiver
ANALOG ELECTRICAL CHARACTERISTICS
100BASE-TX Transmitter
PARAMETER
CONDITION
MIN
NOM
MAX
UNIT
Peak Output Amplitude (|Vp+|, |Vp-|)
(see note below)
Best-fit over 14 bit
times;
950
1050
mVpk
0.5 dB Transformer
loss
Output Amplitude Symmetry
|Vp +|
0.98
3
1.02
|Vp -|
Output Overshoot
5
5
%
ns
ps
ps
Percent of Vp+, Vp-
10-90% of Vp+, Vp-
|tr - tf|
Deviation from best-fit
time-grid;
Rise/Fall time (tr, tf)
Rise/Fall time Imbalance
Duty Cycle Distortion
500
±250
010101... Sequence
Scrambled Idle
Jitter
1.4
ns
Note: Measured at the line side of the transformer.
Test Condition: Transformer P/N: TLA-6T103
Line Termination: 100Ω ±1%
100BASE-TX Transmitter (Informative)
The specifications in the following table are included for information only. They are mainly a function of the
external transformer and termination resistors used for measurements.
PARAMETER
Return Loss
CONDITION
2 < f < 30 MHz
30 < f < 60 MHz
MIN
16
MAX
UNIT
dB
f
16 − 20 log
30MHz
10
60 < f < 80 MHz
-8 < Iin < 8 mA
Open-Circuit Inductance
350
µH
Page: 27 of 35
© 2009 Teridian Semiconductor Corporation
Rev 1.3
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
