Four Output Differential Buffer for PCI Express

ICS9DB401C

REV E 03/18/08

ICS9DB401C

Four Output Differential Buffer for PCI Express

7

SRC Reference Clock

Common Recommendations for Differential Routing

Dimension or Value

Unit

Figure

L1 length, Route as non-coupled 50 ohm trace.

0.5 max

inch

1

L2 length, Route as non-coupled 50 ohm trace.

0.2 max

inch

1

L3 length, Route as non-coupled 50 ohm trace.

0.2 max

inch

1

Rs

33

ohm

1

Rt

49.9

ohm

1

Down Device Differential Routing

Dimension or Value

Unit

Figure

L4 length, Route as coupled microstrip 100 ohm differential trace.

2 min to 16 max

inch

1

L4 length, Route as coupled stripline 100 ohm differential trace.

1.8 min to 14.4 max

inch

1

Differential Routing to PCI Express Connector

Dimension or Value

Unit

Figure

L4 length, Route as coupled microstrip 100 ohm differential trace.

0.25 to 14 max

inch

2

L4 length, Route as coupled stripline 100 ohm differential trace.

0.225 min to 12.6 max

inch

2

Figure 1 Down device routing.

Rs

Rs

Rt

Rt

HSCL Output

Buffer

PCI Ex Board

Down Device

REF_CLK Input

L1

L2

L3’

L4

L1’

L2’

L3

L4’

Figure 1

Figure 2 PCI Express Connector Routing.

Rs

Rs

Rt

Rt

HSCL Output

Buffer

PCI Ex

Add In Board

REF_CLK Input

L1

L2

L3’

L4

L1’

L2’

L3

L4’

Figure 2