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Distributed-Load Backplane Switching Characteristics

0.25”

Drvr

1.5 V

0.25”

1”

1”

1”

1.5 V

1”

1”

1”

Rcvr

Rcvr

Rcvr

Slot 1

Slot 2

Slot 19

Slot 20

Conn.

Conn.

Conn.

Conn.

From Output

Under Test

Test

Point

1.5 V

11

Ω

SN74GTLPH1645

16-BIT LVTTL-TO-GTLP ADJUSTABLE-EDGE-RATE BUS TRANSCEIVER

SCES290D – OCTOBER 1999 – REVISED JUNE 2005

The preceding switching characteristics table shows the switching characteristics of the device into a lumped

load (Figure 1). However, the designer's backplane application probably is a distributed load. The physical

representation is shown in Figure 2. This backplane, or distributed load, can be approximated closely to a

resistor inductance capacitance (RLC) circuit, as shown in Figure 3. This device has been designed for optimum

performance in this RLC circuit. The following switching characteristics table shows the switching characteristics

of the device into the RLC load, to help the designer better understand the performance of the GTLP device in

this typical backplane. See www.ti.com/sc/gtlp for more information.

Figure 2. High-Drive Test Backplane

Figure 3. High-Drive RLC Network

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