0

50

100 150 200 250 300 350 400

BELDEN 1694A CABLE LENGTH (m)

0

5

10

15

20

25

30

LMH0387

SNLS315G – APRIL 2010 – REVISED APRIL 2013

www.ti.com

Figure 5. CLI vs. Belden 1694A Cable Length

OUTPUT MODE (CABLE DRIVER) DESCRIPTION

INPUT INTERFACING

The LMH0387 cable driver accepts differential input signals which can be DC or AC coupled.

OUTPUT INTERFACING

The LMH0387 cable driver uses 75

be properly terminated with a 4.7 µF capacitor followed by a 75

Ω resistor to ground as shown.

OUTPUT SLEW RATE CONTROL

The LMH0387 cable driver output rise and fall times are selectable for either SMPTE 259M or SMPTE 424M /

292M compliance via the SD/HD pin. For slower rise and fall times, or SMPTE 259M compliance, SD/HD is set

high. For faster rise and fall times, or SMPTE 424M and SMPTE 292M compliance, SD/HD is set low. SD/HD

has an internal pulldown.

OUTPUT ENABLE

The LMH0387 cable driver can be enabled or disabled with the TX_EN pin. When set low, the cable driver is

powered off. TX_EN has an internal pullup to enable the cable driver by default. When using the LMH0387 in the

input mode (as an equalizer), the cable driver must be disabled by setting the TX_EN pin low.

APPLICATION INFORMATION

PCB LAYOUT RECOMMENDATIONS

For information on layout and soldering of the laminate TLGA package, pease refer to the following application

note: AN-1125 (SNAA002), “Laminate CSP/FBGA.”

For a CSP package, it is a general requirement not to have any metal (traces or vias) on the top layer in

the area directly underneath the device, other than the footprint. This is intended to provide a flat planar

surface for the package.

14

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