MAX9568 Maxim Integrated Products, MAX9568 Datasheet - Page 13

• Manufacturer Part Number: MAX9568
• Description: Component Analog TV Sync Separator
• Manufacturer: Maxim Integrated Products

CSYNCOUT reproduces the component video input
waveform with the active video removed. This output
contains all the information below the component video
black level. CSYNCOUT is pulled high whenever sync
is not detected at the component video input. See
Figures 2a and 2b for composite sync output timing
diagrams.
VSYNCOUT produces a pulse signal that defines the
beginning of a new field in interlaced systems or frame
in progressive systems. This output pulses low whenev-
er the vertical sync pulse interval is detected. See
Figure 4 for vertical sync output timing diagrams.
HSYNCOUT produces a pulse signal that defines the
beginning of the horizontal line. This output pulses low
whenever a horizontal sync pulse is detected. For inter-
lace standards, the horizontal pulse output rate remains
constant. See Figures 2a and 2b for horizontal sync
output timing diagrams.
SDTV, HDTV, and HL produce logic outputs that indi-
cate the standard of the component video signal at the
input. SDTV output high indicates standard-definition
television while SDTV output low indicates extended
definition or high-definition television.
HDTV output high indicates high-definition television
while HDTV output low indicates standard-definition or
extended definition television.
HL output high indicates 625i, 625p (576p), and 1080i
standards while HL output low indicates 525i, 525p
(480p), and 720p standards. See Table 1.
LOS produces logic output that indicates the presence
of a video input signal. LOS output high indicates that
there is a sync or video signal at the input while LOS
low indicates the presence of a component video sig-
nal at CVIDIN.
CLAMP produces a pulse signal that is generally used
to drive a black-level clamp circuit which restores the
DC component to a video signal. This output pulses low
during black-level (back porch) of each video line. See
Figures 2a and 2b for clamp pulse output timing dia-
grams.
Composite Sync Output ( CSYNCOUT )
Horizontal Sync Output ( HSYNCOUT )
Vertical Sync Output ( VSYNCOUT )
Standard- and High-Definition TV
Clamp Pulse Output ( CLAMP )
______________________________________________________________________________________
Detection (SDTV, HDTV, HL)
Loss-of-Sync Output ( LOS )
Component Analog TV Sync Separator
The MAX9568 provides a vertical interval coast output
which allows the PLL oscillator to coast through the ver-
tical interval. This output pulses low during vertical
blanking interval.
ODD/EVEN produces a square wave that identifies the
present field of an interlaced video source. ODD/EVEN
output low indicates odd field while ODD/EVEN output
high indicates even field. This square wave changes
coincidentally with the beginning of the vertical pulse.
If the input signal is standard-definition composite
video, a simple lowpass filter is recommended in front
of the input to attenuate the chroma signal, or any high-
frequency noise below the black level. As shown in
Figure 5, when the input is standard-definition video,
SDTV is logic-high and Q1 is turned on. When Q1 is on,
R1 and C2 form a 600kHz lowpass filter to attenuate
high-frequency noise and improve the performance of
the MAX9568. When the input is high-definition video or
extended definition video, SDTV is logic-low and Q1 is
turned off, disabling the RC input filter.
Figure 4. Vertical Sync Output Timing Diagrams
Figure 5. Chroma Filter
Odd and Even Field Detection ( ODD /EVEN)
VSYNCOUT
VSYNCOUT
V
IN
CVIDIN
CVIDIN
1kΩ
MMBT3904
R1
270pF
Applications Information
C2
Q1
TRILEVEL SYNC PULSES
BILEVEL SYNC PULSES
0.1μF
C1
t
VP
CVDIN
MAX9568
t
10kΩ
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VP
R2
Chroma Filter
SDTV
Coast
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