Digital Signal Processing Reference
In-Depth Information
NEXT
Saturates at
Kb
dv
×
Long victim
(dt < 2 tpd)
2 tpd
NEXT
= 2
Kb
tpd
(
dv dt
/
)
××
Short victim
(dt > 2 tpd)
dv
Aggressor
dt
Voltage
Time
Figure 10.5
Width and amplitude of NEXT pulse appearing on victim depends on length of cou-
pled region. NEXT on short lines grows in proportion to the length. It saturates at a maximum value
when the line is long.
LC
⎛
L
⎞
1
(
)
Kb
=
×
m
+
Z
×
C
(10.2a)
⎜
⎟
o
m
⎝
Z
⎠
4
×
o
s
s
dV
(
)
(10.2b)
NEXT
=×
2
Kb
×
tpd
×
when
dt
≥
2
tpd
dt
(
)
NEXT
=×
Kb
dV
when
dt
<
2
tpd
(10.2c)
tpd
=
length
×
L
×
C
(10.2d)
s
s
It is evident from (10.2a) that the relationship between the trace impedance
and the coupling inductance (
L
m
) and capacitance (
C
m
) determines the NEXT
