ISL59960

9

FN8358.0

December 18, 2012

Functional Description

960MegaQ™ Overview

960MegaQ™ is a fully automated, stand-alone equalizer for both

960H (WD1) and 720H (D1) composite video resolutions

transmitted over UTP (Unshielded Twisted Pair, i.e., Cat 5, Cat 6,

etc.) or coaxial (RG-59) cables.

Differential video signals sent over long distances of twisted pair

wire exhibit large high frequency attenuation, resulting in loss of

high frequency detail/blurring. The exact loss characteristic is a

complex function of wire gauge, length, composition, and

coupling to adjacent conductors.

The video signal can be restored by applying a filter with the

exact inverse transfer function to the far end signal. 960MegaQ™

is designed to compensate for the losses due to long cables, and

incorporates the functionality and flexibility to match a wide

variety of cable types and loss characteristics.

While 960MegaQ™ was designed and optimized for stand-alone

operation, with no need for any external control of any kind, it has

an optional SPI serial interface with some additional features.

See “Additional Equalization Modes Available With the Serial

Interface” on page 11 for more information on the features and

operation of the serial interface.

Equalization for Various Cable Types

TABLE 1. CABLE TYPES AND LENGTHS

CABLE TYPE

MAXIMUM

LENGTH SUPPORTED

Copper-Core

Cat 5/Cat 5e

4000 feet

Cat 6

4000 feet

Coaxial - RG-59

5000 feet

Non-Copper-Core (Note)

Cat 5/Cat 5e CCA

(Copper-Coated Aluminum Core)

2000 feet

Coaxial - RG-59 CCS

(Copper-Coated Steel Core)

1500 feet

NOTE: Image quality will be significantly improved over unequalized

cable, but there will still be some image smearing due to the high

resistance of the core material.

FIGURE 9. APPLICATION CIRCUIT FOR UTP CABLE

75.0

Ω

SD

SEN

SCK

IN-

GND

GND

IN+

OUT

CFB

1.0µF

49.9

Ω

0.47µF

DIFFERENTIAL

VIDEO INPUT+

SERIAL

INTERFACE

(OPTIONAL)

DIFFERENTIAL

VIDEO INPUT-

1k

Ω

0.047µF

0.1µF

Internally

Generated

+5V

300

Ω

INVERT

EQ_DISABLE

COLOR

LOCKED

FREEZE

1.0µF

49.9

Ω

ISL59960

Ferrite Bead –

DC resistance = 1

Ω

,

600

Ω at 100MHz,

100mA DC current rating

Freezes EQ once

lock is achieved.

Tie FREEZE low if

not used.

4.7µF

0.1µF

1500pF

C1

C2

R1

R2

R3

C4 R5

C5

R6

VIDEO

OUT

C6

C7

C8

C9

5V

TVS

5V

TVS

Z1

Z2

TVS = Transient Voltage Suppressor

a.k.a. Transorb