Video sync separator saves components, simplifies controls

The National Semiconductor LMH1980 sync separator makes multi-source video systems easier to use and more responsive, with automatic detection of the video input format to provide appropriate timing signals and external flags.

This capability eliminates the need to adjust an external resistor for each input format, which saves component count and adds end-user benefits including easy operation with fewer buttons.

The LMH1980 accepts analogue video input signals with either bi-level or tri-level syncs, and generates CMOS-logic-compatible timing outputs including composite, horizontal and vertical syncs, burst/backporch timing and odd/even field outputs. An HD-Detect pin is also provided, which allows an external SD chroma filter to be disabled when a high-definition input with tri-level sync is detected.

Standard video formats supported include PAL and NTSC standard-definition signals, 720-lines and 1080-lines high-definition formats, and many VESA-compatible timing standards. If a non-standard input format is detected, the LMH1980 generates a default vertical sync pulse.

 

FEATURES Operating voltage range: 3.3V to 5V Fixed-level sync slicing for video inputs from 0.5Vpp to 2Vpp 14mA supply current @ 5V 10-lead MSOP package

APPLICATIONS Multi-source video systems Automotive LCD panels Industrial video Surveillance systems Machine vision and inspection systems Test and measurement equipment

 

National Semiconductor/LMH1980