TB430: Video Sync Separator, Horiz Genlock

EL4583, EL4584, EL4585 Demo Board
®
Technical Brief
Video Sync Separator, Horiz Genlock
EL4583 and EL4584
The EL4583, EL4584, EL4585 demo
board is designed to demonstrate the
operations of Intersil’s family of sync separators and
horizontal genlocks. The board as assembled is designed to
accept NTSC standard video through A4, Video In. The
EL4583 separates H-sync and sends it through jumper R10
to the EL4584. H-sync can be monitored at A1, H-sync. On
the board settings, the internal divider mode is selected and
the divider N is set to 910. The EL4584 uses its internal
divider to extract a clock pulse of the same H-sync input
frequency from the oscillator and adjusts the on-board LC
VCO to phase lock this signal to the input horizontal
frequency. This divided clock signal can be monitored at A2,
EXT DIV. The full clock frequency (which should equal to
H-sync (15.734kHz)*divider (910) = 14.318MHz) is available
at A3, CLK OUT. Each board has been tested with a NTSC
signal and C17 adjusted so EXT DIV locks to the H-sync.
SW1 has 3 positions. LEFT grounds COAST and puts the
EL4584 into normal mode (see data sheet for mode
descriptions). CENTER floats COAST and is fast lock mode,
and RIGHT pulls COAST to VDD and is coast mode. The
signal should lock in normal mode. The DIP switches at the
top of the board works as follows: from right to left, the
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February 24, 2004
TB430
switches should be labeled 1, 2, 3, 4. Dip-SW4 controls pin
B, SW3 controls C, SW2 controls A, and SW1 controls DIV
SEL pin 7 on the EL4584. Refer to the data sheet for a table
of divisors for each switch setting and the operation of DIV
SEL. If using a NTSC signal, setting all switches ON will
produce a CLK OUT frequency of 14.318MHz, and an EXT
DIV frequency of 15.734kHz, and the EL4584 will lock.
To convert the oscillator to work with the standard PAL
frequency of 17.734MHz, simply substitute an inductor of
about 8.2µH to bring the center frequency up closer to PAL
frequency of 17.734MHz, and reset the dip switches to
A = 0, B = 1, C = 1. Remember that LC VCOs have a wide
pull range so they are very tolerant of component variations.
In some cases the 10µH inductor may be able to produce
the necessary PAL frequency as well as the NTSC
frequency.
Crystal VCXOs and 4-pin VCXO hybrids can also be used.
See the accompanying schematics and data sheet for more
info.
EL4585
An EL4585 can be used in place of the EL4584 provided.
With R1 changed to 3.3µH and the same settings as in the
EL4584 section, The signal frequency at CLK OUT is
28.636MHz.
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Technical Brief 430
EL4583, EL4584, EL4585 Schematic
4
3
2
1
VDD
5
6
7
8
SW2
PROGRAM
R8
10K
U2
R5
1
10K
R7
2
10K
C17
3
L1/R2 OPEN
Y1
5pF-30pF
VDD
Note: Values for L1
For EL4584, L1=10uH, Fosc = 14.318MHz.
For EL4585, L1=3.3uH, Fosc = 28.636MHz
10uH
C10
PROG A
C
HSYNC
OSC OUT
DIG GND
ANALOG VDC
EXT DET
16
R9
10K
A3
CLK-OUT
15
14
4
A2
EXT-DIV
13
0.1uF
OSC IN
LOCK DET
12
TP7
8
VDD
GNDOUT
14
VcomVCC
C6
B
VDD
5
220pF
EL4584CS/EL4585CS
Y2
VCXO
6
ANALOG GND
DG VDD
C12
11
A1
0.1uF
OPEN
7
CHARGE PUMP HSYNC IN
H-SYNC
10
7
1
VDD
8
SMV1212-001
R4
R12 13K
1
FLT CUT OFF
ANALOG GND
100K
DV SEL
COAST
9
SW1
2
R10
0
1
3
C5
0.01uF
V1
R1
30K
C1
0.001uF
16
R13 82K
C7
A4
VIDEO IN
R3
R6
75
0
0.1uF
2
LEV DET
HSYNC
15
VDD
3
TP1
CSYNC
C8
4
0.1uF
C2
5
OPENTP2
VSYNC
6
CSYNC
U1
EL4583CS
FLTER IN
VDD
ODD/EVEN
13
7
GND
C11
0.1uF
8
2
TP3
0.1uF
ODD/EVEN
VSYNC
GND
RSET
BP CLAMP
12
11
TP6
BP CLAMP
VDD
VDD
C14
14
FILTER OUT
NO SIGNAL
VIDEO IN
LEVEL OUT
10
9
R15
680K
C9
0.1uF
Error : intersil.bmp file not found.
Title
TP5
NO SIGNAL
TP4
LEVEL OUT
Size:
EL1881/4581/3/4/5 DEMO BOARD
Revision:
A
Date: 12/17/03
File: EL4583 4 Sch
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Sheet
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Technical Brief 430
The VCO and loop filter section of the EL4583/4/5 demo board can be implemented in the
following configurations:
(1) VCXO
VSUPPLY
CONTROL
Charge Pump
Output
R4
C5
C1
GND
R1
1
14
7
8
IN
PIN 5
(2) XTAL
TO OSC IN
PIN 5
OUT
PIN 3
R2
Y1
Charge Pump
Output
C6
R4
PIN 7
C17
R1
C5
C1
V1
IN
PIN 5
(3) LC Tank
OUT
PIN 3
L1
C6
220pF
Charge Pump
Output
10µH
R4
PIN 7
C5
0.01µF
R1
30K
C17
100K
C1
0.001µF
5.5 - 30pF
V1
SMV1212-001
Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to
verify that the Application Note or Technical Brief is current before proceeding.
For information regarding Intersil Corporation and its products, see www.intersil.com
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