ISL59601_14 Datasheet, PDF (20/28 Pages) Intersil Corporation – MegaQ™: An Automatic Composite Video Equalizer,Fully-Adaptive to 1 Mile (1600m)

ISL59601, ISL59602, ISL59603, ISL59604, ISL59605
Functional Description
MegaQ™ Overview
MegaQ™ is a fully automated, stand-alone equalizer for
composite video 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. MegaQ™ 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 MegaQ™ 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 22 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
CAT5/CAT5e
5300 feet
CAT6
5600 feet
Coaxial - RG-59
6000 feet
CAT2/CAT3
(telephone wire)
3000 feet
Belden IMSA Spec 39-2 581718
(3-pair traffic light cable)
5300 feet
Non-Copper-Core*
CAT5/CAT5e CCA
(Copper-Coated Aluminum Core)
2000 feet
Coaxial - RG-59 CCS
(Copper-Coated Steel Core)
1500 feet
*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.
Ferrite Bead –
DC resistance = 1Ω,
600Ω at 100MHz,
100mA DC current rating +5V
C7
0.1µF
C8 C9
0.1µF 4.7µF
DIFFERENTIAL
VIDEO INPUT+
5V _Z1
TVS
DIFFERENTIAL
VIDEO INPUT-
5V _Z2
TVS
C1
1.0µF
R3 ^{R1 49.9}
1k _{R2 49.9}
1.0µF
C2
TVS = Transient Voltage Suppressor
a.k.a. Transorb
SERIAL
INTERFACE
(OPTIONAL)
V_DD1
IN+
V_DD2
OUT
GND
CFB
IN- ISL59601
ISL59602
ISL59603 _VREF
ISL59604
ISL59605
SEN
SCK
SD
EQ_DISABLE
COLOR
INVERT
LOCKED
GND
FREEZE
R6 75.0 _VIDEO
C5
300 _0.047µF
OUT
C4 ^R5
1500pF
Internally
Generated
C6
0.47µF
Freezes EQ once
lock is achieved.
Tie FREEZE low if
not used.
FIGURE 45. APPLICATION CIRCUIT FOR UTP CABLE
20
FN6739.2
September 5, 2012