ISL59601 Datasheet, PDF (20/27 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 23 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.
DIFFERENTIAL
VIDEO INPUT+
DIFFERENTIAL
VIDEO INPUT-
OPTIONAL FERRITE BEAD –
~1kΩ AT 100MHz,
~105mA DC CURRENT
+5V
C7
0.1μF
FB1
C8
C9
0.1μF 4.7μF
R3 ^R1
C1
1.0μF
V_DD1
IN+
49.9
V_DD2
OUT
1k
R2
49.9
IN-
C2 ^1.0μF
ISL59601
ISL59602
ISL59603
ISL59604
ISL59605
CFB
VREF
SERIAL
INTERFACE
(OPTIONAL)
SEN
SCK
SD
EQ_DISABLE
COLOR
INVERT
LOCKED
GND
FREEZE
R6 75.0
300
C5
0.022μF
C4 R5
1500pF
INTERNALLY
GENERATED
C6
0.47μF
VIDEO OUT
FREEZES EQ ONCE LOCK IS ACHIEVED
FIGURE 45. APPLICATION CIRCUIT FOR UTP CABLE
20
FN6739.1
November 23, 2010