CLC014 datasheet(14/17 Pages) NSC

14 / 17 page

Typical Applications (Continued)

DIGITAL VIDEO (SDV) ROUTERS

The CLC014 provides performance that complies with the

SMPTE 259M standard for serial digital video (SDV) trans-

mission over coaxial cable. One common application is in

SDV routers, which provide a switching matrix for connecting

video source equipment (e.g., cameras) to destination equip-

ment (e.g., video tape recorders, monitors, etc.).

Figure 12 shows a typical configuration for an SDV router,

including equalizers, a crosspoint switch, data retimers, and

cable drivers. The CLC014 is used in its standard configu-

ration in this application, and automatically equalizes cable

lengths from zero meters to greater than 300 meters at

360 MHz (see plots in Typical Performance Characteris-

tics section). The equalized outputs are connected to the

differential inputs of the crosspoint switch. The CLC016 Data

Retimer receives the data from the crosspoint and performs

the clock and data recovery functions, further reducing jitter.

Finally, the retimed data is driven into the coaxial cable by a

CLC006 Cable Driver (with two amplitude-adjustable out-

puts) or a CLC007 Cable Driver (with four outputs).

TWISTED PAIR DRIVER

A low-cost medium for transmitting data is twisted pair. Cat-

egory 5 UTP has an attenuation characteristic similar to

Belden 8281 coaxial cable but scaled in length: 120 meters

of Category 5 UTP is roughly equivalent to 300 meters of

Belden 8281 cable. When properly implemented, the

CLC014 will equalize data rates up to 625 Mbps over Cat-

egory 5 UTP. The maximum data rate depends upon the

cable length. A plot of Maximum Data Rate vs Cable Length

is found in the Typical Performance Characteristics sec-

tion for Belden 8281, and can be scaled as stated above to

estimate maximum cable lengths and data rates for UTP.

10005631

FIGURE 11. Typical Repeater Design

10005632

FIGURE 12. Video Routing Block Diagram

CLC014 Datasheet(PDF) 14 Page - National Semiconductor (TI)