s Block Diagram
AN2018S
Correlated Double Sampling IC
s Overview
The AN2018S is used to reduce noise in CCD im-
age sensor output signal. It performs correlated double-
sampling on image signal sent from a CCD sensor to
output clearer image signal.
s Features
Operating on low voltage (V
CC
=4.8V), consuming
little current (I
CC
=12.7mA typ.)
Including a high-speed sampling circuit responding
to 510-830H CCD
6dB or 9dB fixed gain
83-dB high S/N-ratio (at 6dB output)
8
7
6
5
1
2
3
4
6dB OUT
GND
SP1
SP2
9dB OUT
BLK
SIG.IN
V
CC
9dB
6dB
S / H
S / H
BLK
BIAS
+
50k
+
CDS output (9dB)
Blanking pulse input
CCD signal input
V
CC
Sampling pulse input (2)
Sampling pulse input (1)
GND
CDS output (6dB)
Pin No.
1
2
3
4
5
Pin name
6
7
8
p
s Pin Descriptions
Unit:mm
6.5
0.3
4.2
0.3
0.4
0.25
0.4
1.27
0.1
0.1
0.15
0.65
1.5
0.2
5.0
0.3
0.3
8-Pin SOP Package (SOP008-P-0225)
Parameter
Symbol
Rating
Unit
V
CC
I
CC
P
D
T
opr
T
stg
Supply voltage
Supply current
Power dissipation
Operating ambient temperature
Note 1)
Storage temperature
Note 1)
Note 1) Ta=25C except operating ambient temperature and storage temperature.
5.5
18
99
20 to +70
55 to +125
V
mA
mW
C
C
s Absolute Maximum Ratings
16.2
mA
I
CC
V
3
V
8
V
1
G
1
Supply current
Terminal voltage pin (8)
Terminal voltage pin (1)
6dB amp. gain
V
dB
dB
Parameter
min
Condition
typ
max
Unit
Symbol
Note) The value in the above characteristics is not a guaranteed value, but reference one on design.
* The characteristics are of the amplifier itself.
9dB amp. gain
G
2
9.2
V
V
2.78
1.90
1.85
7.0
10.2
12.7
2.63
1.60
1.55
6.0
9.0
2.48
1.30
1.25
5.0
7.8
V
CC
=4.8V
V
CC
=4.8V
Pint, y=4.8V
Input level=300mV
P
P
Input level=300mV
P
P
Terminal voltage pin (3)
AMP frequency characteristics *
AMP common mode
rejection ratio *
Sampling pulse threshold (1)
Sampling pulse threshold (2)
Blanking pulse high level
f
C
CMR
V
THB
V
TH1
V
TH2
V
CC
=4.8V
V
3
=100mV
P
P
10MHz
V
CC
=4.8V
V
3
=100mV
P
P
10MHz
V
CC
=4.8V
V
CC
=4.8V
V
CC
=4.8V
V
3
=300mV
P
P
0.8
0.8
3.5
3.0
35
1.5
1.5
2.2
2.2
dB
dB
V
V
V
s Electrical Characteristics (V
CC
=4.8V, Ta=25
2C)
V
CC
=4.8V
Pint, y=4.8V
V
CC
=4.8V
Pint, y=4.8V
Parameter
Symbol
Range
Operating supply voltage range
V
CC
4.5V to 5.1V
sRecommended Operating Range (Ta=25C)
Note) The above characteristics value, measured at V
CC
=5V, is not a guaranteed value, but reference one on design.
Pin No.
Pin name
Equivalent circuit
1
9dB OUT
V
CC
(4)
DC voltage (V
CC=
5V)
Description
2
3
4
BLK
SIG.IN
SP2
1k
H 3.5V
Black level:
1.55V
50k
50
A
5
s Pin Descriptions
6
7
8
L 0.5V
Black level:
2.6V
V
CC
4.8V
H 2.2V
L 0.8V
SP1
H 2.2V
L 0.8V
GND
6dB OUT
Black level:
1.6V
Same as for Pinq.
1
3
5
6
GND
(7)
1k
63k
33k
V
CC
(4)
75
A
200
1k
58k
500
38k
300
A
300
A
1k
1k
28k
20k
28k
20k
8
GND (7)
V
CC
(4)
GND (7)
V
CC
(4)
GND (7)
V
CC
(4)
GND (7)
9-dB-amp. output CDS signal
Typical 1.55V DC output
90-
output impedance
Blanking (Hclear) pulse input (from
an AN2145 series only)
Active high
3.0V threshold voltage
50k
input impedance
Grounded or left open when not
used
CCD signal input
CCD signal must be input through
a capacitor.
The capacitor should preferably be
0.022
F.
2.6V typ. bias voltage
Sample-hold pulse input
Active high
1.5V threshold voltage
Sampling pulses are input in syn-
chronization with the video timing
of CCD signal at Pine.
Sample-hold pulse input
Active high
1.5V threshold voltage
Sampling pulses are input in syn-
chronization with the feed-through
timing of CCD signal at Pine.
Supply voltage
Ground
6-dB-amp. output CDS signal
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