MAXIM MAX7461 Technical data

General Description

The MAX7461 single-channel loss-of-sync alarm (LOS)
provides composite video sync detection in NTSC,
PAL, and SECAM standard-definition television (SDTV)
systems. The MAX7461’s advanced detection circuitry
delivers robust performance by preventing false loss­of-sync alarms due to noise. The device accepts an
AC-coupled composite (CVBS), luma (Y), or any other
video signal with sync, and outputs a logic-level signal.
The open-drain LOS output is low when no sync is
detected and high impedance when sync is detected.
The device operates from a single +5V supply.

The MAX7461 is available in a 5-pin SOT23 package
and is specified for operation over the -40°C to +85°C
temperature range.

Applications

Security Systems

Automotive Rear Seat Entertainment (RSE)
Systems

Consumer Electronics

Features

♦ Accepts CVBS, Y, or Any Other Video with Sync

♦ Loss-of-Sync Alarm Output

♦ Robust Performance in Noisy Environments

♦ Wire-OR Alarm Output

♦ NTSC, PAL, and SECAM

♦ Small 5-Pin SOT23 Package

MAX7461

Loss-of-Sync Alarm

________________________________________________________________ Maxim Integrated Products 1

19-0553; Rev 0; 5/06

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.

Ordering Information

PART

TEMP RANGE

PIN-

PACKAGE

CODE

MAX7461EUK

5 SOT23-5 U5-2

Pin Configuration

CLAMP

LPF

SYNC
DETECTOR

GND

LOS

75Ω

+5V

0.1µF

V

CC

SYNC
SLICE
LEVEL

LOS

FILTER

V

CC

0.1µF

1kΩ

1

5

3

4

SYNC

C

IN

IN

RO

MAX7461

Functional Diagram

PACKAGE

-40°C to +85°C

TOP VIEW

15V

GND

IN

MAX7461

2

CC

34

SOT23-5

LOSGND

MAX7461

Loss-of-Sync Alarm

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

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..............................................................-0.3V to +6V

LOS to GND..............................................................-0.3V to +6V

IN to GND.................-0.3V to the lower of +6V and (V

CC

+ 0.3V)

Continuous Power Dissipation (T

A

= +70°C)

5-Pin SOT23-5 (derate 7.1mW/°C above +70°C) ......571.0mW

Maximum Current Into Any Pin .........................................±50mA

Operating Temperature Range

MAX7461EUK ...................................................-40°C to +85°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

Junction Temperature......................................................+150°C

ELECTRICAL CHARACTERISTICS

(VCC= +4.5V to +5.5V, GND = 0, CIN= 0.1µF, RO = 500Ω, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA=
+25°C.)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

AC CHARACTERISTICS

Minimum Input Sync Height

AC-coupled (Note 1) 105 130

mV

P-P

Maximum Input Voltage

AC-coupled 2.4

V

P-P

LOS Release Time t

RT

(Note 2) 1.7 2.2 2.7

LOS Detect Time t

DT

(Note 3) 1.9 3.4 4.9

ms

DIGITAL CHARACTERISTICS

Output Low Voltage V

OL

I

SINK

= 10mA 0.4 V

Logic High Leakage Current I

OLEAK

1µA

POWER REQUIREMENTS

Supply Voltage V

CC

4.5 5.0 5.5 V

Supply Current I

CC

1.7 2.2 mA

Power-Supply Noise Immunity V

PSNI

0 to 5MHz sinusoid on VCC (Note 4) 200

mV

P-P

Note 1: Minimum input sync height is the voltage above which LOS is guaranteed to be in high-impedance mode after the maximum

LOS time-constant time.

Note 2: LOS release time is the time that the video input must be continuously present before LOS goes high (inactive state).
Note 3: The LOS detect time is the time that the video input must be continuously absent before LOS goes low (active state).
Note 4: The MAX7461 LOS output is accurate with a power-supply noise level below V

PSNI

.

V

IN-MIN

V

IN-MAX

MAX7461

Loss-of-Sync Alarm

_______________________________________________________________________________________ 3

IN

500mV/div

t = 10ms/div

CVSB LOS ALERT TRANSIENT

MAX7461 toc01

LOS

5V/div

3.0

2.5

2.0

1.5

1.0

4.5 4.94.7 5.1 5.3 5.5

LOS DETECT TIME

vs. SUPPLY VOLTAGE

MAX7461 toc02

SUPPLY VOLTAGE (V)

TIME (ms)

4.0

3.5

3.0

2.5

2.0

4.5 4.94.7 5.1 5.3 5.5

LOS RELEASE TIME

vs. SUPPLY VOLTAGE

MAX7461 toc03

SUPPLY VOLTAGE (V)

TIME (ms)

0.20

0.15

0.10

0.05

0

4.5 4.94.7 5.1 5.3 5.5

SYNC HEIGHT LOS ALERT THRESHOLD

vs. SUPPLY VOLTAGE

MAX7461 toc04

SUPPLY VOLTAGE (V)

SYNC HEIGHT (V)

1.6

1.8

1.7

1.9

2.0

-40 0-20 20 40 60 80

SUPPLY CURRENT

vs. TEMPERATURE (CVBS INPUT)

MAX7461 toc05

TEMPERATURE (°C)

I

CC

(mA)

Typical Operating Characteristics

(VCC= 5V, GND = 0, CIN= 0.1µF, RO = 10kΩ, TA= +25°C, unless otherwise noted.)