EL4581C

Sync Separator 50% Slice S-H Filter

Note All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication however this data sheet cannot be a ‘‘controlled document’’ Current revisions if any to these

specifications are maintained at the factory and are available upon your request We recommend checking the revision level before finalization of your design documentation

1993 Elantec Inc

Features

 NTSC PAL and SECAM sync

separation

 Precision 50% slicing internal

caps

 Built-in color burst filter

 Decodes non-standard verticals

 Pin compatible with LM1881

 Low power

 Typically 15 mA supply current

 Resistor programmable scan rate

 Few external components

 Available in 8-pin DIP and SO-8

pkg

Applications

 Video special effects

 Video test equipment

 Video distribution

 Displays

 Imaging

 Video data capture

 Video triggers

Ordering Information

Part No

Temp Range

Package Outline

EL4581CN b40 Cto a85 C 8-Pin DIP MDP0031

EL4581CS b40 Cto a85 C 8-Lead SO MDP0027

Demo Board

A dedicated demo board is not

available However this device can

be placed on the EL45845 Demo

Board

General Description

The EL4581C extracts timing information from standard nega-

tive going video sync found in NTSC PAL and SECAM broad-

cast systems It can also be used in non standard formats and

with computer graphics systems at higher scan rates by adjust-

ing a single external resistor When the input does not have

correct serration pulses in the vertical interval a default verti-

cal output is produced

Outputs are composite sync vertical sync burstback porch

output and oddeven output The later operates only in inter-

laced scan formats

The EL4581C provides a reliable method of determining correct

sync slide level by setting it to the mid-point between sync tip

and blanking level at the back porch This 50% level is deter-

mined by two internal self timing sample and hold circuits that

track sync tip and back porch levels This also provides a degree

of hum and noise rejection to the input signal and compensates

for varying input levels of 05 p-p to 20 Vp-p

A built in linear phase third order low pass filter attenuates

the chroma signal in color systems to prevent incorrectly set

color burst from disturbing the 50% sync slide

This device may be used to replace the industry standard

LM1881 offering improved performance and reduced power

consumption

The EL4581C video sync separator is manufactured using

Elantec’s high performance analog CMOS process

Connection Diagram

EL4581C SO P-DIP Packages

4581 – 1

Top View

Manufactured under US Patent No 5528303