LMH1981 Datasheet, PDF (4/24 Pages) National Semiconductor (TI) – Multi-Format Video Sync Separator

LMH1981
SNLS214H – APRIL 2006 – REVISED MARCH 2013
LMH1981 Test Circuit
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R_EXT
10 k:, 1%
C₄
4.7 PF
C₁
0.1 PF
V_CC
CVBS/Y/G
VIDEO INPUT
R_T
75:
C_IN
1 PF
C₂
0.1 PF
V_CC
R_S
HORIZONTAL
SYNC OUTPUT
1
R_EXT
14
OEOUT
2
GND
13
BPOUT
3
V_CC1
12
CSOUT
4
V_IN
LMH1981
11
V_CC3
5
GND
10
GND
6
V_CC2
7
HSOUT
9
VFOUT
8
VSOUT
R_S
ODD/EVEN
FIELD OUTPUT
R_S
BURST/BACK PORCH
TIMING OUTPUT
R_S
COMPOSITE
SYNC OUTPUT
V_CC
C₃
0.1 PF
R_S
VIDEO FORMAT
OUTPUT
R_S
VERTICAL SYNC
OUTPUT
Figure 2. Test Circuit
The LMH1981 test circuit is shown in Figure 2. The video generator should provide a low-noise, broadcast-
quality signal over 75Ω coaxial cable which should be impedance-matched with a 75Ω load termination resistor
to prevent unwanted signal distortion. The output waveforms should be monitored using a low-capacitance probe
on an oscilloscope with at least 500 MHz bandwidth. See PCB LAYOUT CONSIDERATIONS for more
information about signal and supply trace routing and component placement.
4
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