ZXFV4583
SYNC SEPARATOR WITH VARIABLE FILTER
DEVICE DESCRIPTION
FEATURES AND BENEFITS
The ZXFV4583 provides the ability to separate out
video synchronization signals for a wide variety of TV
and CRT display systems, standard and non-standard.
• PAL, NTSC, SECAM
• Variable filter for optimal accuracy
• Sync outputs: composite, horizontal, vertical, back
porch, odd/even
Flexibility arises from the use of just three external
resistors to adapt to each application. One resistor
controls a fully integrated internal color carrier filter
with variable bandwidth. This filter avoids disturbance
from the color carrier, permitting accurate threshold
slicing for timing extraction.
• No-signal detector
• On chip sample / hold capacitors
• +5V single supply
• Default vertical output where there are no
serration pulses
A second resistor controls the voltage threshold for
loss of signal detection after a time-out interval. The
third resistor controls the timing functions.
• Pin and layout compatible with part EL4583 in
DC restoration for displays is facilitated by the Back
Porch synch output, which can be used to drive an
external circuit to clamp the blanking voltage to a fixed
level.
APPLICATIONS
SO16N surface mount package
• Digital image capture
• Video input systems requiring separation of
picture timing
ORDERING INFORMATION
Part Number
Container
ZXFV4583N16TA
Reel 7″
ZXFV4583N16TC
Reel 13″
• Video distribution
Increment
• CCTV surveillance
500
• Digital multimedia
2500
• Timing for black level clamp
CONNECTION DIAGRAM
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1
SEMICONDUCTORS
ZXFV4583
ABSOLUTE MAXIMUM RATINGS
Supply voltage VCC
-0.5V to +7V
Inputs to ground*
-0.5V to VCC +0.5V
Operating temperature range
-40⬚C to 85⬚C
Storage
-65⬚C to +150⬚C
Operating ambient junction temperature
TJMAX150⬚C**
**The thermal resistance from the semiconductor die to ambient is typically 120⬚C/W when the SO16 package is
mounted on a PCB in free air. The power dissipation of the device when loaded must be designed to keep the
device junction temperature below TJMAX.
*During power-up and power-down, these voltage ratings require that signals be applied only when the power
supply is connected.
ELECTRICAL CHARACTERISTICS
VCC = 5V, RSET = 681k⍀, RFILT = 22k⍀, RNOSIG = 82k⍀, Tamb = 25⬚C unless otherwise stated.
Test level:
P = 100% production test
C = Characterized only
PARAMETER
CONDITIONS
TEST
MIN
TYP
MAX UNIT
P
2
4.5
6.5
mA
1.2
1.35
1.5
V
DC Characteristics
Supply current
Clamp voltage at FILTIN
Pin 4 unloaded
P
Discharge current at FILTIN
Pin 4, Vin = 2V pk-pk
C
Discharge current at FILTIN
Pin 4, no signal
C
3
6
12
A
Clamp charge current at FILTIN
Pin 4, Vin = 1V pk-pk
P
2
3
4
mA
Clamp voltage at FVIDIN
Pin 8 unloaded
P
1.2
1.35
1.5
Discharge current at FVIDIN
Pin 8, Vin = 2V pk-pk
C
Discharge current at FVIDIN
Pin 8, no signal
C
Clamp charge current at FVIDIN
Pin 8, Vin = 1V pk-pk
A
1
3
6
V
〈
1
12
〈
P
2
3
4
mA
R SET voltage, pin 12
P
1.5
1.75
2
V
R FILT voltage, pin 1
P
0.35
0.5
0.65
V
RNOSIG current, pin 2
P
1.5
2.5
3.5
A
0.35
0.8
V
Logic output low voltage, V OL
I OL = 1.6mA
P
ISSUE 3 - NOVEMBER 2003
SEMICONDUCTORS
2
ZXFV4583
ELECTRICAL CHARACTERISTICS (Cont.)
VCC = 5V, RSET = 681k⍀, RFILT = 22k⍀, RNOSIG = 82k⍀, Tamb = 25⬚C unless otherwise stated.
PARAMETER
CONDITIONS
TEST MIN TYP MAX
UNIT
AC Characteristics
FILTIN function input voltage range
PAL/NTSC
P
0.5
Filter voltage gain
FILTIN to FILOUT
P
4.9
5.7
Filter attenuation
4.4MHz for PAL,
3.6MHz for NTSC
P
P
15
10
19
14
Slice level
Vin = 1V pk-pk
P
40
CSYNC prop. Delay, t CS
Relative to pin 4 input
50
P
250
VSYNC delay
C
250
VSYNC pulse width, t VSYNC (PAL)
C
VSYNC pulse width, t VSYNC (NTSC)
C
VSYNC default delay, t VSD
P
HSYNC delay
P
HSYNC pulse width, t HSYNC
P
BKPCH delay, t BD
Relative to pin 4 input
Note:
V pk-pk
6.5
dB
dB
dB
60
400
36
s
45
250
3.8
2.7
ns
s
195
30
%
ns
165
P
P
BKPCH pulse width, t B
2
s
ns
s
5
6.2
250
400
ns
3.7
4.7
s
In order to avoid coupling between high speed logic output signals and analog inputs, the test circuit
layout uses connections from the logic output pins routed away from the analog pins. In the application,
similar care in the layout is required, keeping resistors RFILT, RNOSIG and RSET close to their respective
pins, in particular routing signal CSYNC away from pins 1, 2 and 12.
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SEMICONDUCTORS
ZXFV4583
CONNECTIONS
PIN No.
PIN NAME
TYPE
FUNCTION
1
R FILT
Resistor
control
Controls the input color carrier filter characteristic. An external
resistor R FILT connected from this pin to 0V sets the bandwidth.
Smaller R FILT gives increased bandwidth. See the detailed operating
description below.
2
R NOSIG
Resistor
control
Controls the no-signal detector level. An external resistor R NOSIG
connected from this pin to 0V sets the threshold voltage level,
according to the equation
V PMIN = 0.75 R NOSIG / R SET
where V PMIN is the minimum detected sync pulse amplitude at pin 4
and R SET is the resistor value at pin 12.
3
CSYNC
Logic out
Composite sync logic output. Includes all sync pulses derived from
the input video.
4
FILTIN
Input to color carrier filter. This is the main analog (unfiltered)
composite video input used when color carrier filtering is required. A
Analog in voltage clamp circuit and adaptive current source are also included
at this node. See the detailed operating description. When the filter
is not used, this pin must be left open circuit.
5
VSYNC
Logic out
Vertical sync output. This is an active low pulse commencing on the
first vertical sync pulse trailing (rising) edge and ending near the
second next equalizing pulse. See timing diagram.
6
OVD
Ground
Provides ground return path for internal logic output buffer circuits.
Normally connected externally to a common PCB ground plane.
7
FILTOUT
Analog out Analog output signal from color carrier filter. The filter voltage gain
is nominally 2. This output is normally capacitor-coupled to pin 8.
8
FVIDIN
Input for filtered analog video signal input. This is the direct input
to the sample/hold and sync slicing comparator providing the logic
Analog in timing edges. This input is normally coupled via an external
capacitor from FILTOUT, pin 7. It may be used as the signal input
where the color carrier filter is not required. Includes a clamp
similar that of pin 4.
9
VLEV
10
NOSIG
Analog out Analog output, a positive voltage typically equal to twice the
(negative) peak sync pulse amplitude if the filter is used.
Logic out
Logic output, which goes high after a time-out delay when no signal
is present. The threshold level is controlled at pin 2.
11
BKPCH
Logic out
Burst or Back Porch logic output, an active low monostable pulse
triggered from rising composite sync pulse edges. The width is set
by R SET to overlap most of the steady part of the back porch,
assuming the color carrier burst has been attenuated sufficiently by
filtering. This pulse is then suitable for controlling an external black
level clamping circuit. See the timing diagram.
12
R SET
Resistor
control
Controls the timing interval of the sample/hold circuit and the
monostable interval for the sync outputs according to the
application. An external resistor, R SET connected from this pin to 0V
establishes the timing parameter, to which these times are scaled
together. See the detailed operating description.
13
ODDFLD
Logic out
Odd field logic output. High during an odd numbered field, low
during even. This output is timed with the start of the VSYNC pulse.
14
V+
Power in
Power supply input, +5V.
15
HSYNC
Logic out
Horizontal sync logic output. Monostable output derived from
CSYNC falling edges, it achieves a steady stream of 5µs pulses. The
half line events during the field blanking interval are eliminated. See
timing diagram.
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SEMICONDUCTORS
4
ZXFV4583
DETAILED DESCRIPTION
Introduction
This device includes all the functions required to separate
out the critical timing points of most types of video signal.
A sample-and-hold process is used to establish
accurately the 50% point of the sync pulse. The input is
also filtered to avoid the effect of the color carrier. The
filter is coupled externally. The following paragraphs
give a simplified description of the signal processing.
The vertical sync output VSYNC is derived from the
Field pulse group. Where there are short equalization
pulses in the standard systems, these short pulses are
ignored. Essentially, a pulse width discriminator
circuit senses the first of the Field pulses, as they are
wider than those of the rest of the sequence. The
trailing edge of the first negative-going Frame Pulse
(i.e. the rising edge of the first “serration” pulse)
triggers the VSYNC output. In systems with a frame
interval with no serration pulses, a vertical sync output
is provided after a default delay as in Figure 4. Also
provided is an ODDFLD logic output, which is high
during an odd-numbered field and low during an even
one.
Color carrier filter
This low-pass filter provides adjustable attenuation of
the color carrier with low distortion of the remaining
sync pulses so as to ensure accurate timing of the
extracted logic outputs. The control is via an external
resistor R FILT connected from pin 1 to ground.
R FILT =22k⍀ gives corner frequency of ∼1.3MHz
c o r r e s p ondi ng t o ~ 12dB at t enu a t i o n @
3.58MHz.(Corner freq. Proportional to 1/R FILT ,
minimum value 18k⍀). A graph shows how the
bandwidth varies with the resistor value.
The horizontal sync HSYNC is a monostable output
derived from the leading (falling) edge of the
composite sync. The pulse width is about 5 µs. Also,
during the Field blanking sequence, the additional
half-line pulses are removed by a timing circuit with a
pulse interval discrimination function controlled by
RSET. RSET is normally set to 681k⍀ for standard PAL or
NTSC timings. Consequently the scan rate is inversely
proportional to RSET.
Clamping circuits
Clamping circuits are use to limit the signal swing
excursion after AC coupling at both the input to the
filter, FILTIN and the timing extractor input, FVIDIN. In
each case, the sync tip level is maintained at a value of
nominally 1.35V.
The Back Porch monostable output BKPCH is initiated
from the trailing edge of the composite sync. The pulse
is active low and the width is set according to RSET.
Sync timing extraction circuits
Loss-of-Signal detector
The waveforms are depicted in Timing Diagrams,
Figure 1 for PAL (625 lines) and Figure 2 for NTSC (525
lines). Sample-and-hold circuits are used to obtain
time-delayed voltage values of the sync tip and the
back porch. The sample gates are controlled by a
comparator sensing the video input relative to a
threshold at a fixed offset above the sync tip clamp
level. The sampled voltages are combined in a
potential divider to derive the mean voltage (50%
amplitude), which is used as the sync pulse threshold.
A second comparator then provides CSYNC, the logic
version of the composite sync signal. This is delayed
slightly as shown in Figure 3. The time delay
comprises that of the input filter and also the smaller
delay of the comparator and logic. The timing of the
sample hold and other time parameters are all
controlled together in unison by the external resistor
RSET. A 1% resistor tolerance is recommended. The
sync tip voltage level from the sample-and-hold is
buffered and provided as an analog output, VLEV.
Loss of signal is indicated by a logic high level at the
output NOSIG. The decision threshold is set by an
external resistor RNOSIG connected from pin 2 to
ground. RNOSIG =100k⍀ gives a shut off threshold of
∼250mV of sync amplitude at FVIDIN or ~130mV on
FILTIN (Threshold proportional to RNOSIG, minimum
value 82k⍀) The table of connections above gives the
equation used to determine a suitable resistor value. A
waiting time of nominally 600 µs occurs before the loss
of signal is flagged.
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5
SEMICONDUCTORS
ZXFV4583
FRAME 1
FIELD BLANKING
VIDEO INPUT
621
620
622
624
623
1
625
2
3
4
5
6
7
23
8
CSYNC OUTPUT
VSYNC OUTPUT
HSYNC OUTPUT
BACK PORCH OUTPUT, BKPCH
SEE FIGURE 3 FOR DETAIL
Figure 1: PAL 625 TIMING DIAGRAM
VIDEO INPUT
523
524
525
1
2
3
4
5
6
7
8
9
10
11
20
CSYNC OUTPUT
VSYNC OUTPUT
HSYNC OUTPUT
BACK PORCH OUTPUT, BKPCH
Figure 2: NTSC TIMING DIAGRAM
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SEMICONDUCTORS
6
ZXFV4583
FVIDIN VIDEO INPUT
50%
tCS
CSYNC OUTPUT
tBD
BKPCH OUTPUT
tB
Figure 3: SYNC SLICING & OUTPUT DETAIL
LINE PERIOD
FVIDIN VIDEO INPUT
TVSD
VSYNC OUTPUT
Figure 4: VERTICAL SYNC DEFAULT
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SEMICONDUCTORS
ZXFV4583
TYPICAL CHARACTERISTICS
ISSUE 3 - NOVEMBER 2003
SEMICONDUCTORS
8
ZXFV4583
TYPICAL CHARACTERISTICS (Cont.)
ISSUE 3 - NOVEMBER 2003
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SEMICONDUCTORS
ZXFV4583
APPLICATIONS INFORMATION
General guidance
Parts List
The ZXFV4583 is a high speed mixed analog/digital
s i g n a l pr oc e s s i ng c om pone nt re q u i r i n g t h e
appropriate care in the layout of the application printed
circuit board. A continuous ground plane construction
is preferred. Suitable power supply decoupling
suggested includes a 100nF leadless ceramic capacitor
close to the power supply connection at pin 14.
QTY
CCTREF
VALUE
DESCRIPTION
Resistors, surface mount
In order to avoid coupling between high speed logic
output signals and analog inputs, the test circuit layout
uses connections from the logic output pins routed
away from the analog pins. In the application, similar
care in the layout is required, keeping resistors, RFILT,
RNOSIG, and RSET close to their respective pins, in
particular routing signal CSYNC away from pins 1, 2
and 12.
1
R1
51⍀
0805
1
R2
22k⍀
0805
1
R3
82k⍀
0805
1
R4
681k⍀
0805
2
R5, R12
2.2k⍀
0805
3
R6, R7, R8
1k⍀
0805
1
R9
130⍀
0805
1
R10
33⍀
0805
1
R11
24⍀
0805
Capacitors, surface mount
Evaluation circuit
5
An evaluation circuit is available, designed to provide
demonstration of the ZXFV4583 function using 50 ⍀
test instruments. The schematic diagram is shown in
Figure 5 and the printed circuit layout is shown in
Figures 6, 7 and 8. The circuit includes the Zetex
ZXFV4089 DC Restoration Circuit, which is described in
the data sheet for that part. The ZXFV4089 uses the
Back Porch output from the ZXFV4583 in order to
control and stabilize the black level of a video
waveform.
C1, C2,
C3, C5, C6
100nF
ceramic X7R 50V 0805
1
C4
1nF
ceramic NPO 50V 0805
1
C7
10nF
ceramic X7R 50V 0805
2
C8, C9
10F
tantalum elec 16V
size C
Integrated circuits
BNC connector sockets allow connection of the
analog video and output to laboratory test
instruments via 50 ⍀ BNC cables. The circuit can be
adapted for 75 ⍀ use. The output circuit includes a
resistor matching circuit to present a load of 150 ⍀ to
the amplifier and simultaneously provide 50 ⍀ output
impedance. The attenuation of this matching circuit is
15.45 dB. As the amplifier is configured for a voltage
gain of 2, the overall gain in a 50 ⍀ system is:
1
U1
-
ZXFV4583N16 - Zetex
1
U2
-
ZXFV4089N8 - Zetex
Miscellaneous
6 - 15.45 = -9.45 dB.
The synchronized logic outputs are brought to a header
for examination using oscilloscope probes. A set of
jumper links allow the selection of operation with or
without the built in color carrier filter. The selection is
depicted on the board itself.
2
J1, J2
-
Socket BNC PCB
straight flange e.g.
Tyco B35N14H999X99
1
J3
-
Terminal block 3-way
IMO 20.501/3SB
1
PL1
-
Header 8 way single
row 2.54mm, Harwin
M20-9990805
1
PL2
-
Header 8 way double
row 2.54mm, Harwin M
3
TP1, TP2,
TP3
-
Test terminal, W.
Hughes 200-207
2
LK1, LK2
-
Jumper Link, Harwin
M7567-05
ISSUE 3 - NOVEMBER 2003
SEMICONDUCTORS
10
ZXFV4583
Figure 5: Evaluation circuit board schematic
ISSUE 3 - NOVEMBER 2003
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SEMICONDUCTORS
ZXFV4583
Figure 6: Evaluation circuit layout: Top side
Figure 7: Evaluation circuit layout: Bottom side (viewed through board)
ISSUE 3 - NOVEMBER 2003
SEMICONDUCTORS
12
ZXFV4583
Figure 8: Evaluation circuit layout: Component layout
ISSUE 3 - NOVEMBER 2003
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SEMICONDUCTORS
ZXFV4583
PACKAGE OUTLINE
D
L
E
H
⍜
Pin1
A
c
A1
Seating Plane
e
b
Millimeters
Inches
DIM
MIN
MAX
MIN
MAX
A
1.35
1.75
0.053
0.069
A1
0.10
0.25
0.004
0.010
b
0.33
0.51
0.013
0.020
c
0.19
0.25
0.008
0.010
D
9.80
10.00
0.386
0.394
E
3.80
4.00
0.150
0.157
e
H
1.27BSC
5.80
0.050BSC
6.20
0.228
0.244
h
0.25
0.50
0.010
0.020
L
0.40
1.27
0.016
0.050
⍜
0°
8°
0°
8°
Conforms to JEDEC MS-012AC Iss C (SO16N)
© Zetex plc 2003
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Streitfeldstraße 19
D-81673 München
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Germany
Telefon: (49) 89 45 49 49 0
Fax: (49) 89 45 49 49 49
europe.sales@zetex.com
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Telephone: (1) 631 360 2222
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Telephone: (852) 26100 611
Fax: (852) 24250 494
asia.sales@zetex.com
Europe
Zetex plc
Fields New Road
Chadderton
Oldham, OL9 8NP
United Kingdom
Telephone (44) 161 622 4444
Fax: (44) 161 622 4446
hq@zetex.com
These offices are supported by agents and distributors in major countries world-wide.
This publication is issued to provide outline information only which (unless agreed by the Company in writing) may not be used, applied or reproduced
for any purpose or form part of any order or contract or be regarded as a representation relating to the products or services concerned. The Company
reserves the right to alter without notice the specification, design, price or conditions of supply of any product or service.
For the latest product information, log on to
www.zetex.com
ISSUE 3 - NOVEMBER 2003
SEMICONDUCTORS
14