ELANT EL1881CS-T7, EL1881CS-T13, EL1881CS, EL1881CN Datasheet
EL1881C
Sync Separator, Low Power
EL1881C
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
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
2V
(sync tip amplitude 143mV to 572mV). A single external resis-
P-P
P-P
and -
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 following 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 -40°C to +85°C temperature
range.
Connection Diagram
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
Demo Board
Composite Sync Out
Composite Video In
Vertical Sync Out
A dedicated demo board is available.
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.
GND
1
2
3
4
8
VDD 5V
7
Odd/Even Output
6
RSET
5
Burst/Back Porch Output
September 18, 2001
EL1881C
Sync Separator, Low Power
EL1881C
Absolute Maximum Ratings (T
VCC Supply 7V
Storage Temperature -65°C to +150°C
Pin Voltages -0.5V to V
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: TJ = TC = TA.
= 25°C)
A
CC
+0.5V
Operating Ambient Temperature Range -40°C to +85°C
Operating Junction Temperature 150°C
Power Dissipation 400mW
DC Characteristics
V
= 5V, TA = 25°C, R
DD
Parameter Description Min Typ Max Unit
IDD, Quiescent VDD = 5V 0.75 1.5 3 mA
Clamp Voltage Pin 2, I
Clamp Discharge Current Pin 2 = 2V 6 12 16 µA
Clamp Charge Current Pin 2 = 1V -1.3 -1 0.7 mA
R
Pin Reference Voltage Pin 6 1.1 1.22 1.35 V
SET
VOL Output Low Voltage IOL = 1.6mA 0.24 0.5 V
VOH Output High Voltage
= 681kΩ, unless otherwise specified.
SET
= -100µA 1.35 1.5 1.65 V
LOAD
IOH = -40µA 4 4.8
IOH = -1.6mA 3 4.6
V
Dynamic Characteristics
Parameter Description Min Typ Max Unit
Comp Sync Prop Delay, t
Vertical Sync Width, t
Vertical Sync Default Delay, t
Burst/Back Porch Delay, t
Burst/Back Porch Width, t
Input Dynamic Range Video Input Amplitude to Maintain 50% Slice Spec 0.5 2 V
Slice Level V
CS
VS
BD
B
See Figure 2 20 35 75 ns
Normal or Default Trigger, 50%-50% 190 230 300 µs
See Figure 3 35 62 85 µs
VSD
See Figure 2 120 200 300 ns
See Figure 2 2.5 3.5 4.5 µs
SLICE/VCLAMP
55 70 85 mV
P-P
2
Pin Descriptions
Pin Number Pin Name Pin Function
1 Composite
2 Composite
3 Vertical Sync
4 GND Supply ground
5 Burst/Back
6 R
7 Odd/Even
8 VDD 5V Positive supply (5V)
1. R
SET
Sync Out
Video In
Porch Output
SET
Output
must be a 1% resistor
Composite sync pulse output; sync pulses start on a falling edge and end on a rising edge
AC coupled composite video input; sync tip must be at the lowest potential (positive picture phase)
Vertical sync pulse output; the falling edge of vert sync is the start of the vertical period
Out
Burst/back porch output; low during burst portion of composite video
[1]
An external resistor to ground sets all internal timing; a 681k 1% resistor will provide correct timing for NTSC signals
Odd/even field output; high during odd fields, low during even fields; transitions occur at start of vert sync pulse
EL1881C
EL1881C
Sync Separator, Low Power
3
EL1881C
Sync Separator, Low Power
EL1881C
Typical Performance Curves
Supply Current vs Temperature
R
=681kΩ
SET
1.65
1.6
1.55
1.5
1.45
Supply Current (mA)
1.4
1.35
-50 -25 25 75 100
Clamp Discharge Current vs Temperature
R
SET
11.4
11.3
11.2
11.1
11
10.9
Clamp Discharge Current (µA)
10.8
10.7
5.5V
5V
4.5V
0 50 -50 -25 25 75 1000 50
Temperature (°C)
=681kΩ
5.5V
5V
4.5V
Temperature (°C)
V
Voltage vs Temperature
CLAMP
R
=681kΩ
SET
1.535
1.525
1.515
(V)
CLAMP
V
1.505
1.495
1.485
V
vs Temperature
RSET
R
=681kΩ
SET
1.24
1.235
1.23
1.225
(V)
1.22
RSET
V
1.215
1.21
1.205
1.2
-50 -25 25 75 1000 50-50 -25 25 75 1000 50
5.5V
5V
4.5V
Temperature (°C)
5.5V
5V
4.5V
Temperature (°C)
Clamp Charge Current vs Temperature
R
=681kΩ
SET
1.1
1.05
1
0.95
Clamp Charge Current (mA)
0.9
0.85
5V
-50 -25 25 75 1000 50
Temperature (°C)
5.5V
4.5V
R
vs Horizontal Frequency
SET
1000
800
600
(kΩ)
SET
R
400
200
0
10 15 25 35 40 45
20 30
Frequency (kHz)
4
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