Note: All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication; however, this data sheet cannot be a "controlled document". Current revisions, if any, to these
specifications are maintained at the factory and are available upon your request. We recommend checking the revision level before finalization of your design documentation.
2001 Elantec Semiconductor, Inc.
E
L
1
8
8
1
C
General Description
The EL1881C video sync separator is manufactured using Elantec's
high performance analog CMOS process. This device extracts sync
timing information from both standard and non-standard video input.
It provides composite sync, vertical sync, burst/back porch timing, and
odd/even field detection. Fixed 70mV sync tip slicing provides sync
edge detection when the video input level is between 0.5V
P-P
and
-
2V
P-P
(sync tip amplitude 143mV to 572mV). A single external resis-
tor sets all internal timing to adjust for various video standards. The
composite sync output follows video in sync pulses and a vertical sync
pulse is output on the rising edge of the first vertical serration follow-
ing the vertical pre-equalizing string. For non-standard vertical inputs,
a default vertical pulse is output when the vertical signal stays low for
longer than the vertical sync default delay time. The odd/even output
indicates field polarity detected during the vertical blanking interval.
The EL1881C is plug-in compatible with the industry-standard
LM1881 and can be substituted for that part in 5V applications with
lower required supply current.
The EL1881C is available in the 8-pin PDIP and SO packages and is
specified for operation over the full -40C to +85C temperature
range.
Connection Diagram
1
2
3
4
8
7
6
5
Composite Sync Out
Composite Video In
Vertical Sync Out
GND
VDD 5V
Odd/Even Output
RSET
Burst/Back Porch Output
Features
NTSC, PAL, SECAM, non-
standard video sync separation
Fixed 70mV slicing of video input
levels from 0.5V
P-P
to 2V
P-P
Low supply current - 1.5mA typ.
Single +5V supply
Composite, vertical sync output
Odd/even field output
Burst/back porch output
Available in 8-pin PDIP and SO
packages
Applications
Video amplifiers
PCMCIA applications
A/D drivers
Line drivers
Portable computers
High-speed communications
RGB applications
Broadcast equipment
Active filtering
Demo Board
A dedicated demo board is available.
Ordering Information
Part No.
Package
Tape & Reel
Outline #
EL1881CN
8-Pin PDIP
-
MDP0031
EL1881CS
8-Pin SO
-
MDP0027
EL1881CS-T7
8-Pin SO
7"
MDP0027
EL1881CS-T13
8-Pin SO
13"
MDP0027
EL1881C
Sync Separator, Low Power
S
e
p
t
e
m
b
e
r
1
8
,
2
0
0
1
2
EL1881C
Sync Separator, Low Power
E
L
1
8
8
1
C
Absolute Maximum Ratings
(T
A
= 25C)
V
CC
Supply
7V
Storage Temperature
-65C to +150C
Pin Voltages
-0.5V to V
CC
+0.5V
Operating Ambient Temperature Range
-40C to +85C
Operating Junction Temperature
150C
Power Dissipation
400mW
Important Note:
All parameters having Min/Max specifications are guaranteed. Typ values are for information purposes only. Unless otherwise noted, all tests are at the
specified temperature and are pulsed tests, therefore: T
J
= T
C
= T
A
.
DC Characteristics
V
DD
= 5V, T
A
= 25C, R
SET
= 681k
, unless otherwise specified.
Parameter
Description
Min
Typ
Max
Unit
I
DD
, Quiescent
V
DD
= 5V
0.75
1.5
3
mA
Clamp Voltage
Pin 2, I
LOAD
= -100A
1.35
1.5
1.65
V
Clamp Discharge Current
Pin 2 = 2V
6
12
16
A
Clamp Charge Current
Pin 2 = 1V
-1.3
-1
0.7
mA
R
SET
Pin Reference Voltage
Pin 6
1.1
1.22
1.35
V
V
OL
Output Low Voltage
I
OL
= 1.6mA
0.24
0.5
V
V
OH
Output High Voltage
I
OH
= -40A
4
4.8
V
I
OH
= -1.6mA
3
4.6
Dynamic Characteristics
Parameter
Description
Min
Typ
Max
Unit
Comp Sync Prop Delay, t
CS
See Figure 2
20
35
75
ns
Vertical Sync Width, t
VS
Normal or Default Trigger, 50%-50%
190
230
300
s
Vertical Sync Default Delay, t
VSD
See Figure 3
35
62
85
s
Burst/Back Porch Delay, t
BD
See Figure 2
120
200
300
ns
Burst/Back Porch Width, t
B
See Figure 2
2.5
3.5
4.5
s
Input Dynamic Range
Video Input Amplitude to Maintain 50% Slice Spec
0.5
2
V
P-P
Slice Level
V
SLICE
/V
CLAMP
55
70
85
mV
3
EL1881C
Sync Separator, Low Power
E
L
1
8
8
1
C
Pin Descriptions
Pin Number
Pin Name
Pin Function
1
Composite
Sync Out
Composite sync pulse output; sync pulses start on a falling edge and end on a rising edge
2
Composite
Video In
AC coupled composite video input; sync tip must be at the lowest potential (positive picture phase)
3
Vertical Sync
Out
Vertical sync pulse output; the falling edge of vert sync is the start of the vertical period
4
GND
Supply ground
5
Burst/Back
Porch Output
Burst/back porch output; low during burst portion of composite video
6
R
SET
[1]
An external resistor to ground sets all internal timing; a 681k 1% resistor will provide correct timing for NTSC signals
7
Odd/Even
Output
Odd/even field output; high during odd fields, low during even fields; transitions occur at start of vert sync pulse
8
V
DD
5V
Positive supply (5V)
1. R
SET
must be a 1% resistor
4
EL1881C
Sync Separator, Low Power
E
L
1
8
8
1
C
Typical Performance Curves
Supply Current vs Temperature
R
SET
=681k
1.65
1.6
1.5
1.45
1.4
1.35
-50
-25
25
75
100
Temperature (C)
S
u
p
p
l
y
C
u
r
r
e
n
t
(
m
A
)
5.5V
4.5V
5V
V
CLAMP
Voltage vs Temperature
R
SET
=681k
1.535
1.515
1.505
1.495
1.485
Temperature (C)
V
C
L
A
M
P
(
V
)
V
RSET
vs Temperature
R
SET
=681k
1.24
1.23
1.22
1.21
1.2
Temperature (C)
V
R
S
E
T
(
V
)
Clamp Charge Current vs Temperature
R
SET
=681k
1.1
1
0.9
0.85
Temperature (C)
C
l
a
m
p
C
h
a
r
g
e
C
u
r
r
e
n
t
(
m
A
)
Clamp Discharge Current vs Temperature
R
SET
=681k
11.4
11.3
11.2
10.9
10.8
10.7
Temperature (C)
C
l
a
m
p
D
i
s
c
h
a
r
g
e
C
u
r
r
e
n
t
(
A
)
1.525
11
1.05
0.95
1.55
0
50
-50
-25
25
75
100
0
50
-50
-25
25
75
100
0
50
-50
-25
25
75
100
0
50
-50
-25
25
75
100
0
50
5.5V
5V
4.5V
5.5V
5V
4.5V
5.5V
5V
4.5V
5.5V
4.5V
5V
11.1
1.235
1.225
1.215
1.205
R
SET
vs Horizontal Frequency
1000
600
200
0
10
15
25
35
40
45
Frequency (kHz)
R
S
E
T
(
k
)
800
400
20
30
5
EL1881C
Sync Separator, Low Power
E
L
1
8
8
1
C
Typical Performance Curves
Burst/Back Porch Width vs R
SET
V
DD
=5V, T
A
=25C
6
5
4
3
2
1
200
400
600
800
1000
R
SET
(k
)
B
u
r
s
t
W
i
d
t
h
(
S
)
Vertical Default Delay vs R
SET
V
DD
=5V, T
A
=25C
120
100
60
40
20
0
200
400
600
800
1000
R
SET
(k
)
V
e
r
t
i
c
a
l
S
y
n
c
D
e
f
a
u
l
t
D
e
l
a
y
(
S
)
Burst/Back Porch Width vs Temperature
3.9
3.8
3.6
3.3
3.1
Temperature (C)
B
u
r
s
t
/
B
a
c
k
P
o
r
c
h
W
i
d
t
h
(
S
)
Composite Sync Prop Delay vs Temperature
41
31
-50
-25
0
50
100
Temperature (C)
C
o
m
p
o
s
i
t
e
S
y
n
c
P
r
o
p
D
e
l
a
y
(
n
s
)
80
35
33
3.4
3.2
3.7
3.5
25
75
-50
-25
0
50
100
25
75
5.5V
5V
4.5V
39
37
Burst/Back Porch Delay vs R
SET
V
DD
=5V, T
A
=25C
350
150
100
50
0
200
400
800
1000
R
SET
(k
)
B
u
r
s
t
/
B
a
c
k
P
o
r
c
h
D
e
l
a
y
(
n
s
)
Vertical Sync Width vs R
SET
V
DD
=5V, T
A
=25C
350
100
50
0
200
400
600
1000
R
SET
(k
)
V
e
r
t
i
c
a
l
S
y
n
c
W
i
d
t
h
(
S
)
200
250
300
300
150
600
800
250
200
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