Description
The CXA1645P/M is an encoder IC that converts
analog RGB signals to a composite video signal. This
IC has various pulse generators necessary for
encoding. Composite video outputs and Y/C outputs for
the S terminal are obtained just by inputting composite
sync, subcarrier and analog RGB signals.
It is best suited to image processing of personal
computers and video games.
Features
Single 5V power supply
Compatible with both NTSC and PAL systems
Built-in 75
drivers
(RGB output, composite video output, Y output, C
output)
Both sine wave and pulse can be input as a
subcarrier.
Built-in band pass filter for the C signal and delay
line for the Y signal
Built-in R-Y and B-Y modulator circuits
Built-in PAL alternate circuit
Burst flag generator circuit
Half H killer circuit
Applications
Image processing of video games and personal
computers
Block Diagram and Pin Configuration
Structure
Bipolar silicon monolithic IC
Absolute Maximum Ratings
Supply voltage
V
CC
14
V
Operating temperature Topr
20 to +75
C
Storage temperature
Tstg
65 to +150
C
Allowable power
P
D
CXA1645P 1250 mW
dissipation
CXA1645M 780 mW
Recommended Operating Condition
Supply voltage
V
CC
1, 2 5.0 0.25
V
1
CXA1645P/M
E93411A41-ST
RGB Encoder
Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by
any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the
operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits.
24 pin DIP (Plastic)
24 pin SOP (Plastic)
BPF
PHASE
SHIFTER
R-Y
Modulator
B-Y
Modulator
PULSE
GEN
VIDEO
OUT
75
DRIVER
75
DRIVER
REGULATOR
SYNC
ADD
CLAMP
DELAY
Y/C
MIX
MATRIX
R-OUT
G-OUT
B-OUT
CLAMP
CLAMP
CLAMP
SIN-PULSE
2
3
4
5
1
8
9
6
7
11
12
10
15
16
17
13
14
18
19
20
21
22
23
24
SYNCIN
YCLPC
BFOUT
NPIN
SCIN
BIN
GIN
RIN
GND1
NC
V
CC
1
NC
COUT
YOUT
YTRAP
FO
V
CC
2
BOUT
GOUT
ROUT
GND2
V
REF
I
REF
CVOUT
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2
CXA1645P/M
Pin Description
Externally applied voltage
100
GND1
V
CC
1
I
CLP
180
100
2
3
4
Pin
No.
Symbol
Pin voltage
1
GND1
0V
2
3
4
RIN
GIN
BIN
5
NC
6
SCIN
--
7
NPIN
1.7V
8
BFOUT
H : 3.6V
L : 3.2V
Black level
when
clamped
2.0V
Equivalent circuit
Description
Ground for all circuits other than RGB,
composite video and Y/C output circuits.
The leads to GND2 should be as short and
wide as possible.
Subcarrier input.
Input 0.4 to 0.5Vp-p sine wave or pulse.
Refer to Notes on Operation, Nos. 3 and 5.
Pin for switching between NTSC and PAL
modes
NTSC: V
CC
, PAL: GND
BF pulse monitoring output. Incapable of
driving a 75
load.
Analog RGB signal inputs. Input
100%, = 1Vp-p (max.). To minimize clamp
error, input at as low impedance as
possible.
I
CLP
turns ON only in the burst flag period.
NO CONNECTION
100
GND1
V
CC
1
2.5V
20k
20k
20P
129
6
GND1
V
CC
1
32k
68k
80k
3k
7
GND1
V
CC
1
25
129
8
25
3
CXA1645P/M
Pin
No.
Symbol
Pin voltage
9
YCLPC
2.5V
10
SYNC
IN
12
V
CC
1
5.0V
13
I
REF
2.0V
14
V
REF
4.0V
2.2V
Equivalent circuit
Description
Pin to determine the Y signal clamp time
constant.
Connect to GND via a 0.1F capacitor.
Power supply for all circuits other than RGB,
composite video and Y/C output circuits.
Refer to Notes on Operation. Nos. 4 and 10.
Pin to determine the internal reference
current.
Connect to GND via a 47k
resistor.
Internal reference voltage.
Connect a decoupling capacitor of
approximately 10F.
Refer to Notes on Operation, Nos. 4 and 7.
Composite sync signal input. Input TTL-
level voltages.
L (
0.8V): SYNC period
H (
2.0V)
1.6V
GND1
V
CC
1
5
9
129
GND1
V
CC
1
2.2V
4k
40k
10
GND1
V
CC
1
50
129
13
GND1
V
CC
1
14
4
CXA1645P/M
Pin
No.
Symbol
Pin voltage
15
COUT
2.2V
16
YOUT
17
YTRAP
Black level
1.6V
18
FO
2.0V
Black level
1.3V
Equivalent circuit
Description
Chroma signal output. Capable of driving a
75
load.
Refer to Notes on Operation, Nos. 6 and 9.
Pin for reducing cross color caused by the
subcarrier frequency component of the Y
signal. When the CVOUT pin is in use,
connect a capacitor or a capacitor and an
inductor in series between YTRAP and
GND. Decide capacitance and inductance,
giving consideration to cross color and the
required resolution.
No influence on the YOUT pin.
Refer to Notes on Operation, No. 8.
Internal filter fo adjustment pin.
Connect to GND via the following resistor
according to the NTSC or PAL mode.
NTSC: 20k
(1%)
PAL : 16k
(1%)
Y signal output. Capable of driving a 75
load.
Refer to Notes on Operation, Nos. 6 and 9.
10k
GND2
V
CC
2
15
20k
600
V
CC
1
10k
GND2
V
CC
2
20k
600
V
CC
1
16
GND1
V
CC
1
1.5k
8.5k
0.5P
17
Input resistance 1.5k
GND1
V
CC
1
129
50
18
5
CXA1645P/M
Pin
No.
Symbol
Pin voltage
19
V
CC
2
5.0V
20
CVOUT
21
22
23
BOUT
GOUT
ROUT
Black level
1.7V
24
GND2
0V
Black level
1.2V
Equivalent circuit
Description
Power supply for RGB, composite video and
Y/C output circuits. Decouple this pin with a
large capacitor of 10F or above as a high
current flows.
Refer to Notes on Operation, Nos. 4 and 10.
Analog RGB signal outputs. Capable of
driving a 75
load.
Refer to Notes on Operation, Nos. 6 and 9.
Ground for RGB, composite video and Y/C
output circuits. The leads to GND1 should
be as short and wide as possible.
Composite video signal output. Capable of
driving a 75
load.
Refer to Notes on Operation, Nos. 6 and 9.
10k
GND2
V
CC
2
20k
600
V
CC
1
20
GND2
V
CC
2
500
V
CC
1
5.5k
200
GND1
21
22
23
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