Specifications

Intel
®
810E2 Chipset Platform
R
126 Design Guide
Intrinsic Impedance
Z
L
C
0
0
0
=
(Ω)
Stripline Intrinsic Propagation Speed
S
STRIPLINE
r
0
1017
_
.*
=
ε
(ns/ft)
Microstrip Intrinsic Propagation Speed
S
MICROSTRIP
r
0
1017 0475 067
_
.*.* .
=+
ε
(ns/ft)
Effective Propagation Speed
S
EFF
S
C
D
C
=∗+
0
1
0
(ns/ft)
Effective Impedance
Z
EFF
Z
C
D
C
=
+
0
1
0
(Ω)
Distributed Trace Capacitance
C
S
Z
0
0
0
=
(pF/ft)
Distributed Trace Inductance
L
Z
S
0
12
00
=∗
∗
(nH/ft)
Symbols for the above equations are:
• S
0
is the speed of the signal on an unloaded PCB in ns/ft. This is referred to as the board
propagation constant.
• S
0 MICROSTRIP
and S
0 STRIPLINE
refer to the speed of the signal on an unloaded microstrip or stripline
trace on the PCB in ns/ft.
• Z
0
is the intrinsic impedance of the line in Ω and is a function of the dielectric constant (ε
r
), the line
width, line height and line space from the plane(s). The equations for Z
0
are not included in this
document. See the MECL System Design Handbook by William R. Blood, Jr. for these equations.
• C
0
is the distributed trace capacitance of the network in pF/ft.
• L
0
is the distributed trace inductance of the network in nH/ft.
• C
D
is the sum of the capacitance of all devices and stubs divided by the length of the network’s
trunk, not including the portion connecting the end agents to the termination resistors in pF/ft.
• S
EFF
and Z
EFF
are the effective propagation constant and impedance of the PCB when the board is
“loaded” with the components.