English
Language : 

LMH1980 Datasheet, PDF (1/14 Pages) National Semiconductor (TI) – Auto-Detecting SD/HD/PC Video Sync Separator
July 2007
LMH1980
Auto-Detecting SD/HD/PC Video Sync Separator
General Description
The LMH1980 is an auto-detecting SD/HD/PC video sync
separator ideal for use in a wide range of video applications,
such as automotive LCD monitors, video capture & editing
devices, surveillance & security equipment, and machine vi-
sion and inspection systems.
The LMH1980 accepts an analog video input signal with ei-
ther bi-level or tri-level sync and automatically detects the
video format, eliminating the need for external RSET resistor
adjustment required by other sync separators (e.g.: LM1881).
The outputs provide timing signals in CMOS logic, including
Composite, Horizontal, and Vertical Syncs, Burst/Back Porch
Timing, and Odd/Even Field outputs. The HD flag output (pin
5) provides a logic low signal only when a valid HD video input
with tri-level sync is detected. The HD flag can be used to
disable an external switch-controlled SD chroma filter when
HD video is detected, or enable it when SD video is detected.
For non-standard video with bi-level sync and without vertical
serration pulses, a default vertical sync pulse will be output
and no horizontal sync pulses will be output during the vertical
sync interval.
The LMH1980 is available in a space-saving 10-ld. Mini-SO
Package (MSOP) and operates over a temperature range of
−40°C to +85°C.
Features
■ Analog video sync separation for NTSC, PAL, 480I/P,
576I/P, 720P, 1080I/P/PsF, and many VESA-compatible
timing formats
■ Composite Video (CVBS), S-Video (Y/C), and Component
Video (YPBPR/GBR) and PC Graphics (RGsB) interfaces
■ SD/PC Bi-level sync & HD tri-level sync compatible
■ Composite, Horizontal, and Vertical Sync outputs
■ Burst/Back Porch Timing, Odd/Even Field, and HD Detect
Flag outputs
■ Automatic video format detection
■ Fixed-level sync slicing for video inputs from 0.5 to 2 VPP
■ 3.3V to 5V supply operation
Applications
■ Consumer, Professional, Automotive & Industrial Video
■ Video Capture, Editing, and Processing
■ Genlock Circuits
■ Surveillance & Security Video Systems
■ Set-Top Boxes (STB) & Digital Video Recorders (DVR)
■ LCD / Plasma Displays and Video Projectors
■ Machine Vision and Inspection Systems
■ Video Trigger Oscilloscopes and Waveform Monitors
Connection Diagram
10-ld. MSOP
Top View
FIGURE 1. Pinout
Ordering Information
30010301
Pin Descriptions
Pin No.
1
2
3
4
5
6
7
8
9
10
Pin Name
REXT
GND
VCC
VIN
HD
HSOUT
VSOUT
CSOUT
BPOUT
OEOUT
Pin Description
Bias Current External Resistor
Ground
Supply Voltage
Analog Video Input
HD Detect Flag Output
Horizontal Sync Output
Vertical Sync Output
Composite Sync Output
Burst/Back Porch Timing Output
Odd/Even Field Output
Package
10-ld. MSOP
Part Number
LMH1980MM
LMH1980MMX
Package Marking
AL4A
Transport Media
1k Units Tape and Reel
3.5k Units Tape and Reel
NSC Drawing
MUB10A
© 2007 National Semiconductor Corporation 300103
www.national.com