Document
SONY
RGB Encoder
. CXA1145P/M
Description The CXA 1145P/M encoder converts an ana-
log.RGB signal to a composite video signal. With its built-in circuit various pulses required
for an encoder, composite video outputs are obtained just by inputting the composite sync and analog RGB signal.
Features • Single power supply 5 V • Low power consumption (11 0 mWI • Compatible both with NTSC and PAL
systems • Built-in 750 driver (RGB output, composite
video output, composite sync output) • Built-in oscillator for subcarrier • External input of subcarrier is also possible. • Built-in audio buffer circuit
Functions
• MTX circuit • R-Y, B-Y MOD circuit • Y/C MIX circuit • 750 driver for RGB, composite video and
composite sync outputs • PAL ALT circuit • BF generator • Half H killer circuit • Subcarrier oscillator • Audio buffer circuit
Structure Bipolar silicon monolithic IC
Packa e Outline CXA1145P 24 pin DIP
CXA1145M 24 pin SOP
"
Absolute Maximum Ratings (Ta = 25°C)
• Supply voltage · • Operating temperature • Storage temperature • Allowable power dissipation
Vee Topr Tstg Po
Recommended Operating Condition
10
-20 to +75
-55 to +150
1250
780
• Supply voltage
Vee 5±0.25
ovc oc
mW (CXA 1145P) mW (CXA 1145MI
v
Unit: mm
DIP-24P-01 SOP·24P-L01
-108-
SONY reserves the right to change products and specifications without notice. This Information does not convey any license under patent rights of SONY corporation or others.
70945-TO
CXA1145P/M
Block Diagram and Pin Configuration
CHROMA OUT
y
OUT CHROMA
IN
y
IN
C VIDEO OUT
B
OUT
G
OUT R
OUT
·109-
S O N Y..
C SYNC OUT
C SYNC IN
AUDIO OUT AUDIO
IN NTSC/PAL
IN
B
IN
G
IN R IN
CXA1146P/M
Pin Description
No. Symbol 1 GND 1
2 RIN 3 GIN 4 BIN
SONY.,
Equivalent circuit
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2
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r/r
k
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l
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Description GND pin for circuits other than o~tputs of RGB and composite video. Connect with GND 2 using an impedance as low as possible.
Input pin for the analog RGB signal. Input with 100% = 1 Vp-p. It is necessary to input with an impedance as low as possible to minimize the clamp error allowance.
6 XO OUT 5
t
Ji'>r
6 XOIN
6
1
" ++
Pin for the x'tal OSC. For inner oscillation. a crystal oscillator is con· nected. For external oscillation, Input to pin 6 XO IN through a coupling capacitor. Input with the sub-carrier Input level at 400 mVp-p to 1,000 mVp-p. For external oscillation, input a sine wave with enough less distortion. With much distortion, the chroma signal's phase property may de· teriorate.
.
7 NTSC/PAL
IN 7
.
I
,...,.
jJ I
Switching pin between NTSC and PAL mode.
J Vee NTSC
I GND PAL
·110-
CXA1145P/M No. Symbol
Equivalent circuit
S O N Y..
Description
8 AUDIO IN
8
;;7
JJ
Input pin for the audio buffer circuit.
I The input impedance is about 25 kQ
;;7
9 AUlD OUT
~~
9
r,7
Output pin for the audio buffer circuit.
10 C SYNC IN
10
~
7j
Input pin for the composite sync signal. Input with the TTL level.
L (;;> 0.8 V): Sync. H (~ 2.0 V)
11 C SYNC OUT
11
r
7i'7
12 Vee 1
Output pin for the composite sync signal. Capable of driving a 750 load direct.
Power supply pin for circuits other than RGB and composite video output circuits.
-111-
CXA1145P/M No. Symbol
Equivalent circuit
SONY.,
Description
~
13 I REF 13
r~ ~ ('
Pin to determine the inner reference current. Connect to GND via a 27 kO resistor.
7i'T
~
14
VREF
14
Pin for the inner reference voltage. Connect to GND with 10 ,.F.
I
£;;'r
T.
15
C OUT
15
1r-
£7i'T
Chroma signal output pin. Connect a Band Pass Filter (BPF) between this pin and pin 17 (C IN).
1r-
Y signal output pin.
16 Y OUT
16
Connect a delay line between this pin and pin 18 (YIN).
I
£--;;'r
J
17 CIN 17
l7i
~
7tT
Input pin for the chroma signal without harmonic distortion after BPF.
-112-
CXA1145P/M No. Symbol
Equivalent circuit
SONY~
Description
18 YIN 19 Vcc2
18
,~,.
Input pin for the Y signal with delay after the delay line.
+
Power supply pin for RG8 and composite video output circuits. Decouple with a large·enough capacity as a massive current flows.
20 C VOUT
~
19
•
:r.lr
l ...
Output pin for the Y/C MIX circuit. The composite video signal is output. This output can drive a 750 load direct.
21 8 OUT 22 GOUT 23 ROUT
24 GND2
.~
1
@ @
7:7
.) Output pin for the analog RG8 signal. Capable of driving a 750 load drive.
I
'""
GND pin for RG8 and composite output circuits. Connect with GND 1 using low impedance as possible.
-113-
CXA1145P/M
SONY.,
Electrical Characteristics Ta = 25°C, Vee= 5V, See the Electrical Characteristics Test Circuit
Item Consumption current 1
Symbol
Conditions
lcc1 S1 S2 S3 ON
Test point 11
Min. 15.0
Consumption current 2
lcc2 SG5 DC=2. OV
I 2 6.3
VoiR) RIN = 1Vp-p, f = 200 kHz, Fig. 1
F
RGB output voltage
Vo(G) GIN=1Vp-p, !=200kHz, Fig. 1
E 0.64
VoiB) BIN= 1Vp-p, f =200kHz, Fig, 1
D
RGB output frequency response
fciR)
1----
- fciG) fciB)
Frequency when an output becomes -3 dB with the output of
f = 200 kHz in Fig. 1 set to 0 dB..