19-3267; Rev 2; 11/04
Video-Signal Conditioners with AGC and
Back-Porch Clamp
General Description
The MAX7450/MAX7451/MAX7452 complete front-end
video-signal conditioners are designed to improve the
quality of standard-definition video signals. The devices
restore the DC level of the video input, correct for
amplitude errors up to ±6dB, detect fault conditions,
and filter out-of-band noise. The MAX7450/MAX7451/
MAX7452 optimize the signal quality for further video
processing through a crosspoint switch or video
decoder (ADC). Each device integrates an input video
clamp, automatic gain control (AGC), loss-of-sync
(LOS) detector, and an out-of-band noise/lowpass filter.
These devices also incorporate a user-selectable
buffer gain (0 or +6dB) and an AGC-disable function.
The MAX7450 and MAX7451 operate from dual power
supplies of ±5V or ±3.3V respectively, and they restore
the video blanking level to GND. The MAX7452 operates
from a single +5V supply and features a user-adjustable
clamp level.
The devices are available in an 8-pin SO package with
an exposed pad and are specified for operation over
the extended (-40°C to +85°C) temperature range.
Features
♦
Back-Porch Clamp to GND (MAX7450/MAX7451)
♦
Adjustable Back-Porch Clamp (MAX7452)
♦
Automatic Gain Control (±6dB Range) Normalizes
Signals to Standard Video Level
♦
Input Fault Detection with LOS Output
♦
Inherent 50Hz/60Hz Input Rejection of 60dB
♦
Single-Supply Operation: MAX7452 (+5V)
♦
Out-of-Band Noise Filter
♦
Output Buffer Drives Standard 150Ω Video Load
with 0dB or +6dB Gain
♦
Dual-Supply Operation
MAX7450 (±5V)
MAX7451 (±3.3V)
♦
Tiny 8-Pin SO Package
MAX7450/MAX7451/MAX7452
Ordering Information
PART
†
MAX7450ESA
MAX7451ESA
MAX7452ESA
TEMP RANGE
PIN-
SUPPLY
PACKAGE VOLTAGE (V)
±
5
±
3.3
Applications
Signal Conditioner for Standard-Definition
Video Inputs
Security Video Systems
Video-Switching Systems
-40°C to +85°C 8 SO-EP*
-40°C to +85°C 8 SO-EP*
-40°C to +85°C 8 SO-EP*
+5
*EP
= Exposed pad.
†
Package code = S8E-12.
Functional Diagram
V
CC
GAIN SET (0dB OR +6dB)
VIDEO
INPUT
IN
NOISE
FILTER
±6dB
0 OR +6dB
OUT
75Ω
75Ω
SYNC SEPARATOR
AND AMPLITUDE
DETECTOR
LOS
AGCD
MAX7450
MAX7451
V
SS
GND
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
