LMH1981 Datasheet, PDF (1/24 Pages) National Semiconductor (TI) – Multi-Format Video Sync Separator

LMH1981
www.ti.com
SNLS214H – APRIL 2006 – REVISED MARCH 2013
LMH1981 Multi-Format Video Sync Separator
Check for Samples: LMH1981
FEATURES
1
•2 Standard Analog Video Sync Separation for
NTSC, PAL, 480I/P, 576I/P, 720P, and
1080I/P/PsF from Composite Video (CVBS),
S-Video (Y/C), and Component Video
(YP_BP_R/GBR) Interfaces
• Bi-Level & Tri-Level Sync Compatible
• Composite, Horizontal, and Vertical Sync
Outputs
• Burst/Back Porch Timing, Odd/Even Field, and
Video Format Outputs
• Superior Jitter Performance on Leading Edge
of HSync
• Automatic Video Format Detection
• 50% Sync Slicing for Video Inputs from 0.5 V_PP
to 2 V_PP
• 3.3V to 5V Supply Operation
APPLICATIONS
• Broadcast and Professional Video Equipment
• HDTV/DTV Systems
• Genlock Circuits
• Video Capture Devices
• Set-Top Boxes (STB) & Digital Video
Recorders (DVR)
• Video Displays
DESCRIPTION
The LMH1981 is a high performance multi-format
sync separator ideal for use in a wide range of video
applications, such as broadcast and professional
video equipment and HDTV/DTV systems.
The input accepts standard analog SD/ED/HD video
signals with either bi-level or tri-level sync, and the
outputs provide all of the critical timing signals in
CMOS logic, which swing from rail-to-rail (V_CC and
GND) including Composite, Horizontal, and Vertical
Syncs, Burst/Back Porch Timing, Odd/Even Field,
and Video Format Outputs. HSync features very low
jitter on its leading (falling) edge, minimizing external
circuitry needed to clean and reduce jitter in
subsequent clock generation stages.
The LMH1981 automatically detects the input video
format, eliminating the need for programming using a
microcontroller, and applies precise 50% sync slicing
to ensure accurate sync extraction at O_H, even for
inputs with irregular amplitude from improper
termination or transmission loss. Its unique Video
Format Output conveys the total horizontal line count
per field as an 11-bit binary serial data stream, which
can be decoded by the video system to determine the
input video format and enable dynamic adjustment of
system parameters, i.e.: color space or scaler
conversions. The LMH1981 is available in a 14-pin
TSSOP package and operates over a temperature
range of −40°C to +85°C.
Connection Diagram
R_EXT 1
GND 2
V_{CC1 3}
V_IN 4
GND 5
V_{CC2 6}
HSOUT 7
LMH1981
14 OEOUT
13 BPOUT
12 CSOUT
11 V_CC3
10 GND
9 VFOUT
8 VSOUT
Figure 1. 14-Pin TSSOP - Top View
See PW Package
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2006–2013, Texas Instruments Incorporated