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.
Applications
Signal Conditioner for Standard-Definition
Video Inputs
Security Video Systems
Video-Switching Systems
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
Video-Signal Conditioners with AGC
and Back-Porch Clamp
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
19-3267; Rev 2; 11/04
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.
EVALUATION KIT
AVAILABLE
MAX7450
MAX7451
NOISE
FILTER
V
CC
V
SS
75Ω
75Ω
LOS
SYNC SEPARATOR
AND AMPLITUDE
DETECTOR
AGCD
IN
OUT
VIDEO
INPUT
GND
±6dB
0 OR +6dB
GAIN SET (0dB OR +6dB)
Functional Diagram
*EP = Exposed pad.
†
Package code = S8E-12.
PACKAGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
MAX7450/MAX7451/MAX7452
Video-Signal Conditioners with AGC
and Back-Porch Clamp
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
SUPPLY
= ±5V ±5% (MAX7450), V
SUPPLY
= ±3.3V ±5% (MAX7451), V
SUPPLY
= +5V ±5% (MAX7452), RL=150Ω to GND, CL = 0 to
20pF, GSET = 1, AGCD = 1, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at TA = +25°C.)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
VCCto GND
MAX7450/MAX7452...........................................................+6V
MAX7451 ...........................................................................+4V
V
SS
to GND
MAX7450.............................................................................-6V
MAX7451.............................................................................-4V
OUT
MAX7450/MAX7451 ..........................................-2.5V to +3.5V
MAX7452................................................-0.3V to (V
CC
+ 0.3V)
GSET, AGCD, LOS.....................................-0.3V to (V
CC
+ 0.3V)
All Other Pins
MAX7450/MAX7451...................(-0.3V + V
SS
) to (VCC+ 0.3V)
MAX7452................................................-0.3V to (V
CC
+ 0.3V)
Maximum Current into Any Pin ............……………………±50mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin SO (derate 18.9mW/°C above +70°C)..............1509mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature......................................................+150°C
Lead temperature (soldering, 10s) ..................................+300°C
MAX7450/MAX7451, relative to GND
Clamp Accuracy
MAX7452, relative V
BPLVL
= 1.5V
mV
GSET = 0 1.5 2.4
Back-Porch Level Input Range V
BPLVL
MAX7452
GSET = 1 1.2 2.0
V
Clamp Response Time t
CLAMP
Blanking level at the output to 1% of final
value
70
GSET = 0, relative
to V
OUT
= 1V
P-P
GSET = 1, relative
to V
OUT
= 2V
P-P
%
AGC Input Range AGCD = 0, relative to VIN = 1V
P-P
dB
Gain Flatness G
F
f = 5MHz relative to 100kHz
dB
Noise-Filter Cutoff Fc 10
Low-Frequency Gain f = 100kHz
GSET = 1
V/V
Group-Delay Deviation Δt
G
3.58/4.43MHz relative to 100kHz 15 ns
Differential Gain dG
0.2 0.6 %
Differential Phase dθ
SYMBOL
MIN TYP MAX
±50
±50
VIN = 0.5V
Five-step modulated staircase (VIN = 1V
Five-step modulated staircase (VIN = 1V
to 2V
P-P
P-P
)
P-P
)
P-P
-6.0 +6.0
-0.3 +0.3
0.95
1.85
±10
±10
1.05
2.05
MAX7450/MAX7451/MAX7452
Video-Signal Conditioners with AGC
and Back-Porch Clamp
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(V
SUPPLY
= ±5V ±5% (MAX7450), V
SUPPLY
= ±3.3V ±5% (MAX7451), V
SUPPLY
= +5V ±5% (MAX7452), RL=150Ω to GND, CL = 0 to
20pF, GSET = 1, AGCD = 1, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at TA = +25°C.)
GSET = 0,
V
OUT
= 1V
P-P
68
Signal-to-Noise Ratio SNR
Output signal
peak-to-peak to RMS
GSET = 1,
V
OUT
= 2V
P-P
65
dB
Line Time Distortion H
DIST
18µs, 100 IRE bar 0.2 %
Field Time Distortion V
DIST
130 lines, 18µs, 100IRE bar 0.5 %
Input Leakage Current I
IN
15µA
Output Dynamic Range VIN = 1V
P-P
, dG / dP < 3% / degrees 2 2.4
AGCD = 1 30
Power-Supply Rejection Ratio PSRR
V
CC
+ 100mV
P-P
,
f = 3.5MHz
AGCD = 0 with
maximum gain
20
dB
MAX7450 35
MAX7451 30
Supply Current
MAX7452 20
mA
Logic-High Input V
IH
0.7 x
V
Logic-Low Input V
IL
0.3 x
V
Logic-High Output V
OH
I
SOURCE
= 500µA
V
CC
-
0.5
V
Logic-Low Output V
OL
I
SINK
= 500µA 0.4 V
Input Current Logic-High I
IH
Logic input sink 10 µA
Input Current Logic-Low I
IL
Logic input source 10 µA
SYMBOL
noise (100Hz to 5MHz)
MIN TYP MAX
V
CC
V
CC