© 2004 Fairchild Semiconductor Corporation

www.fairchildsemi.com

FMS6501 Rev. 1.0.4

12

Layout Considerations

General layout and supply bypassing play major roles in

high-frequency performance and thermal characteristics.

Fairchild offers a demonstration board, FMS6501DEMO,

to use as a guide for layout and to aid in device testing

and characterization. The FMS6501DEMO is a 4-layer

board with a full power and ground plane. For optimum

results, follow the steps below as a basis for high fre-

quency layout.

power pin.

power pin.

preferably with a large ground plane under the

package.

inductance.

tances. If routing across a board, place device such

that longer traces are at the inputs rather than the

outputs.

If using multiple, low-impedance, DC-coupled outputs,

special layout techniques may be employed to help dissi-

pate heat.

If a multilayer board is used, a large ground plane

directly under the device helps reduce package case

temperature.

For dual-layer boards, an extended plane can be used.

Worst-case, additional die power due to DC loading can

per channel.

FMS6501 Video Switch Matrix Applications

The increased demand for consumer multimedia sys-

tems has created a challenge for system designers to

provide cost-effective solutions to capitalize on the

growth potential in graphics display technologies. These

applications requires cost-effective video switching and

filtering solutions to deploy high-quality display technolo-

gies rapidly and effectively to the target audience. Areas

of specific interest include HDTV, media centers, and

automotive “infotainment” (includes navigation, in-cabin

entertainment, and back-up camera). In all cases, the

advantages an integrated video switch matrix provides

are high quality video switching specific to the applica-

tion, as well as video input clamps and on-chip, low-

impedance output cable drivers with switchable gain.

Generally the largest application for a video switch is for

the front end of an HDTV, where it takes multiple inputs

and routes them to appropriate signal paths (main pic-

ture and picture in picture - PiP). These are normally

routed into ADCs followed by decoders. There are many

different technologies for HDTV; including LCD, Plasma,

and CRT, with similar analog switching circuitry.

An example of a HDTV application is shown in Figure 14.

This system combines a video switch matrix and two

three-channel switchable anti-aliasing filters. There are

two three-channel signal paths in the system; one for the

main picture, the other for “Picture in Picture” (PiP).

interface. To facilitate demonstration, Fairchild Semicon-

trol software to write to the FMS6501 register map. This

software is included in the FMS6501DEMO kit. Also

cable to connect to the demo board. Besides using the

Figure 14. HDTV Application using the FMS6501 Video Switch Matrix