Datasheet

78Q2120C
10/100BASE-TX
Transceiver
Page: 27 of 35 © 2009 Teridian Semiconductor Corporation Rev 1.3
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;
0.5 dB Transformer
loss
950 1050 mVpk
Output Amplitude Symmetry
|Vp +|
|Vp -|
0.98 1.02
Output Overshoot
Percent of Vp+, Vp-
5 %
Rise/Fall time (tr, tf)
10-90% of Vp+, Vp-
3 5 ns
Rise/Fall time Imbalance
|tr - tf|
500 ps
Duty Cycle Distortion
Deviation from best-fit
time-grid;
010101... Sequence
±250
ps
Jitter Scrambled Idle 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 CONDITION MIN MAX UNIT
Return Loss 2 < f < 30 MHz
30 < f < 60 MHz
60 < f < 80 MHz
16
16 20
30
−






log
f
MHz
10
dB
Open-Circuit Inductance -8 < Iin < 8 mA 350
µH