EL1881 Video Sync Separator

10 January 2020 - 0 Comments

EL1881 Video Sync Separator

EL1881 Video Sync Separator Pinout

The EL1881 video sync separator is manufactured using Elantec’s high-performance analog CMOS process. This device extracts sync timing information from both standard and non-standard video input. It provides composite sync, vertical sync, burst/back porch timing, and odd/even field detection.

Pin Description of EL1881 IC

Pin Number	Pin Name	Description
1	Composite Sync Output (CSOUT)	This is an output pin which provides the stripped out composite signal
2	Composite Video In (CVIN)	This is the input pin to which the video with composite is fed
3	Vertical Sync Out	This pin outputs the composite free filtered video signal
4	Ground (GND)	Connected to the ground of the system
5	Burst/Back Out (BPOUT)	Outputs burst or back porch timing signal
6	Reset	Used to reset the IC
7	Odd/Even Output (OEOUT)
8	VCC	Powered normally with +5V or +12V

EL1881 Specifications

NTSC, PAL, SECAM, non-standard video sync separation
Fixed 70mV slicing of video input levels from 0.5VP-P to 2VP-P
Low supply current - 1.5mA typ.
Single +5V supply
Composite, vertical sync output
Odd/even field output
Burst/back porch output
Available in 8-Pin PDIP and SOIC packages

Equivalent for EL1881: LM1881, EL4581

Alternatives Video sync separators: LM1981, EL1993, EL4583

Where to use the EL1881 Video Sync Separator IC

The EL1881 is used in many video-related application where composite video and RGB video is involved. One noticeable main application of the IC is to convert sync over composite videos (HSYNC + VSYNC + CVBS) into CSYNC video (HSYNC+VSYNC) by removing the composite video (CVBS) aspects. It provides composite sync, vertical sync, burst/back porch timing, and odd/even field detection. This comes in handy while using the old RGB monitors since they do not support composite sync information.

So if you are looking for a composite video conversion IC then LM1881 might be of interest to you.

How to use EL1881 IC

EL1881 can work with a minimum number of components. Along with the IC, it only requires three resistors and some capacitors. The typical connection diagram for EL1881 is shown below.

EL1881 Internal Circuit

The IC has an operating voltage from 5-12V, but normally it is operated either in +5V or +12V. The video with composite is fed to pin 2 the capacitor acts as a parasitic capacitor to filter noise. The output video which is free of composite and can be used on RGB monitors can be obtained from pin 3.