MAX7474 Datasheet, PDF (1/10 Pages) Maxim Integrated Products – Adaptive Equalizer for Video Over Twisted Pair

19-3216; Rev 0; 1/08
EVAALVUAAILTAIOBNLEKIT
Adaptive Equalizer for
Video Over Twisted Pair
General Description
The MAX7474 adaptive equalizer recovers losses
incurred in the transmission of a composite video
(CVBS) signal over unshielded twisted-pair (UTP)
cable. The device fully recovers losses for cable
lengths of up to 300m and greatly improves signal qual-
ity for cable lengths of up to 600m. The device automat-
ically adapts to all cable lengths for CVBS signals with
color burst and allows fixed-equalization settings for
video signals without burst. The MAX7474 is optimized
to provide compensation for losses that occur when
transmitting composite video signals over UTP cables
such as Category 5e. The device compensates for low
frequency and chroma band losses. The MAX7474 is
compatible with NTSC and PAL standards.
The MAX7474 accepts differential input and provides a
single-ended output. The output is capable of driving
two AC- or DC-coupled standard 150Ω video loads.
The output back-porch DC level is adjustable with an
externally applied DC voltage at the BPLVL input. The
device also features loss-of-sync (LOS) and loss-of-burst
(LOB) logic outputs.
The MAX7474 is available in a 16-pin SSOP package
and is fully specified over the extended (-40°C to
+85°C) temperature range.
Applications
Security Video Systems
Video Switching Systems
Home Automation
Features
♦ Automatically Equalizes Up to 600m
(Fully Recovers Losses Up to 300m) of UTP Cable
Carrying CVBS
♦ Automatic Switchover to Fixed Equalization for
CVBS Without Color Burst
♦ Integrated Video Driver with Adjustable
Back-Porch Clamp Level
♦ LOS and LOB Output
♦ NTSC and PAL Compatible
♦ 16-Pin SSOP Package
Ordering Information
PART
TEMP RANGE PIN-PACKAGE
PKG
CODE
MAX7474EAE+
-40°C to +85°C
16 SSOP
(5.3mm x 6.2mm)
+Denotes a lead-free package.
A16+2
Pin Configuration and Typical Application Circuit appear at
end of data sheet.
Functional Diagram
+5V
+5V
CAMERA
UNSHIELDED TWISTED PAIR
(0 TO 300m)
50Ω
0.022µF
INP
INN
0.022µF
50Ω
FEQ0
FEQ1
0.1µF
V_CC
0.1µF
V_CC
CLAMP
ADAPTIVE
EQUALIZER
MAX7474
AGC AND AEQ
CONTROL
BACK-PORCH
CLAMP
GND
OUT
ADC
BPLVL (1.0V TO 1.6V)
LOB
LOS
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.