July 2007
LMH1980
Auto-Detecting SD/HD/PC Video Sync Separator
General Description
Features
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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.
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
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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.
SD/PC Bi-level sync & HD tri-level sync compatible
Composite, Horizontal, and Vertical Sync outputs
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Burst/Back Porch Timing, Odd/Even Field, and HD Detect
Flag outputs
Automatic video format detection
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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
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Video Capture, Editing, and Processing
Genlock Circuits
Surveillance & Security Video Systems
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.
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
Pin Descriptions
Pin No.
Pin Name Pin Description
10-ld. MSOP
1
2
REXT
Bias Current External Resistor
GND
Ground
3
VCC
Supply Voltage
4
VIN
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
5
HD
6
HSOUT
VSOUT
CSOUT
BPOUT
OEOUT
7
8
30010301
Top View
9
10
FIGURE 1. Pinout
Ordering Information
Package
Part Number
LMH1980MM
LMH1980MMX
Package Marking
AL4A
Transport Media
1k Units Tape and Reel
3.5k Units Tape and Reel
NSC Drawing
10-ld. MSOP
MUB10A
© 2007 National Semiconductor Corporation
300103
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