Multimedia ICs
Color TV Signal Encoder
BA7232FS
The BA7232FS converts analog RGB signals into color TV signals in the NTSC and PAL formats. From inputs of
analog RGB signals, a composite synch signal, burst pulses and a color carrier, this IC generates a color TV signal,
and can be adapted for either NTSC or PAL standards, which are selected externally. When set to PAL, the
BA7232FS changes chroma phase according to the burst flag pulses.
The chroma signals and luminosity signals can be combined into a color TV signal or output separately, making this
IC suitable for S pins. Also, this IC comes with an output pin for the analog RGB signal. Each output has a built-in
75Ω driver.
•
Applications
TV peripherals
•
Featuresadapted for NTSC and PAL formats.
1) Can be
2) Internal flip-flop for PAL phase switching.
3) Separate Y / C output pins.
4) Analog RGB signal output pins.
5) Internal 75Ω driver. (outputs color TV signals, lumi-
nosity signals, chroma signals and analog RGB sig-
nals)
6) Adaptable for color subcarrier pulse input.
•
Block diagram
BIN
1
CLAMP
BFP
GIN
2
CLAMP
BFP
RIN
3
CLAMP
BFP
V
CC
MATRIX
BURST
GEN.
V
CC
SYNC
16
PHASE
GEN.
SYNCOUT
17
V
CC
2
V
CC
1
4
75Ω
18
ROUT
75Ω
19
GOUT
75Ω
20
BOUT
SYNC
SYNCIN
5
B - Y MOD.
R - Y MOD.
SYNC
MIX
BFPIN
6
75Ω
15
YOUT
NT / PAL
7
F•F
14
N.C.
Y/C
MIX
SCIN
8
FILTER
75Ω
13
VOUT
GND1
9
GND
12
N.C.
COUT
10
75Ω
GND
11
GND2
1
Multimedia ICs
BA7232FS
•
Pin descriptions
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Pin name
BIN
GIN
RIN
V
CC
1
SYNCIN
BFPIN
NT / PAL
SCIN
GND1
COUT
GND2
N.C.
VOUT
N.C.
YOUT
SYNCOUT
V
CC
2
ROUT
GOUT
BOUT
Analog B signal input
Analog G signal input
Analog R signal input
Power supply pin for all drivers other than the 75Ω driver
Composite synchronization signal input (negative logic)
Burst flag pulse input (negative logic)
Selecting the type of color TV signal output
(high = NTSC, low = PAL)
Color subcarrier input
Ground for all drivers other than the 75Ω driver
Chroma signal output. Internal 75Ω driver.
Ground for the 75Ω driver
This pin is not connected inside the IC.
Color TV signal output. Internal 75Ω driver.
This pin is not connected inside the IC.
Luminance signal output. Internal 75Ω driver.
Composite synchronization signal output
Power supply pin for all drivers other than the 75Ω driver
Analog R signal output. Internal 75Ω driver
Analog G signal output. Internal 75Ω driver.
Analog B signal output. Internal 75Ω driver.
Function
•
Absolute maximum ratings (Ta = 25°C)
Parameter
Power supply voltage
Power dissipation
Operating temperature
Storage temperature
Symbol
V
CC
Pd
Topr
Tstg
Limits
7
750
∗
– 20 ~ + 70
– 55 ~ + 125
Unit
V
mW
°C
°C
∗
Reduced by 7.5mW for each increase in Ta of 1°C over 25°C.
When mounted on a 70
×
70
×
1.6mm glass epoxy board.
•
Recommended operating conditions (Ta = 25°C)
Parameter
Power supply voltage
RIN input level
GIN input level
BIN input level
SCIN input level
Symbol
V
CC
υ
RI
υ
GI
υ
BI
υ
SC
Limits
4.5 ~ 5.5
0 ~ 0.7
0 ~ 0.7
0 ~ 0.7
0.45 ~ 0.6
Unit
V
V
P-P
V
P-P
V
P-P
V
P-P
2
Multimedia ICs
BA7232FS
CC
•
Electrical characteristics (unless otherwise noted, Ta = 25°C, V
Parameter
Current dissipation
Luminance level
Luminance level R
YOUT Luminance level G
VOUT Luminance level B
Synchronization level
Synchronization /
luminance level ratio
R / burst level ratio
G / burst level ratio
B / burst level ratio
R phase
G phase
COUT
B phase
VOUT
Burst level
Carrier leak
PAL burst phase
PAL burst level ratio
SYNCOUT
Output level (HIGH)
Output level (LOW)
Symbol
I
CC
υ
L
υ
L(R)
υ
L(G)
υ
L(B)
υ
S
R
S/L
R
R/BU
R
G/BU
R
B/BU
θ
R
θ
G
θ
B
υ
BU
υ
CL
θ
BU
+
θ
BU
–
R
BU
—
—
υ
RO
υ
GO
υ
BO
V
YO
V
CO
V
VO
V
RO
V
GO
V
BO
V
IL
Min.
33.0
0.63
0.19
0.37
0.07
0.27
0.38
2.84
2.65
2.01
94
231
337
0.26
—
125
215
0.9
2.00
0
0.63
0.63
0.63
1.60
2.20
1.35
1.25
1.25
1.25
—
Typ.
48.0
0.70
0.21
0.41
0.08
0.30
0.43
3.16
2.95
2.24
104
241
347
0.29
—
135
225
1.0
2.50
—
0.70
0.70
0.70
2.00
2.60
1.75
1.65
1.65
1.65
—
Max.
63.0
0.77
0.23
0.45
0.09
0.33
0.48
3.48
3.25
2.47
114
251
357
0.32
35
145
235
1.1
5.00
0.40
0.77
0.77
0.77
2.40
3.00
2.15
2.05
2.05
2.05
0.8
= 5V, XTAL = 3.58MHz)
Conditions
—
υ
RI
=
υ
GI
=
υ
BI
= 0.7V
P-P
υ
RI
= 0.7V
P-P
∗
1
υ
GI
= 0.7V
P-P
∗
1
υ
BI
= 0.7V
P-P
∗
1
—
R
YO
=
υ
S
/
υ
L
υ
RI
= 0.7V
P-P
∗
1
υ
GI
= 0.7V
P-P
∗
1
υ
BI
= 0.7V
P-P
∗
1
∗
1
∗
1
∗
1
∗
3
∗
2
Unit
mA
V
P-P
V
P-P
V
P-P
V
P-P
V
P-P
—
—
—
—
deg
deg
deg
V
P-P
mV
P-P
deg
deg
—
V
V
V
P-P
V
P-P
V
P-P
V
V
V
V
V
V
V
υ
RI
= 0.7V
P-P
υ
GI
= 0.7V
P-P
υ
BI
= 0.7V
P-P
SW1 = 2
∗
1
SW1 = 2
∗
1
SW1 = 2
∗
1
—
—
ROUT output level
GOUT output level
BOUT output level
YOUT DC voltage
COUT DC voltage
VOUT DC voltage
ROUT DC voltage
GOUT DC voltage
BOUT DC voltage
Input voltage "L" level
SYNC, BFP, NT / PAL
Input voltage "H" level
SYNC, BFP, NT / PAL
Input impedance
SYNC, BFP, NT / PAL
—
—
—
—
—
—
—
V
IH
2.2
—
—
V
—
—
Z
I
8
13.5
—
kΩ
∗
1 Guaranteed performance.
∗
2 Measured 3.5
µs
after burst with a 3.58 MHz BPF.
∗
3 Measured with a 3.58 MHz BPF.
Not designed for radiation resistance.
3
Multimedia ICs
BA7232FS
•
Measurement circuit
0.1µ
BIN input
1
CLAMP
BFP
0.1µ
GIN input
2
CLAMP
BFP
0.1µ
RIN input
3
CLAMP
BFP
V
CC
V
CC
4
MATRIX
BURST
GEN.
V
CC
SYNC
16
SYNC
PHASE
GEN.
2K
SYNC
MIX
17
SYNCOUT
measurement point
V
CC
75Ω
75Ω
19
75Ω
20
+
220µ
75
BOUT
measurement point
75
75
GOUT
measurement point
75
75
ROUT
measurement point
75
+
220µ
+
18
220µ
Composite synch
5
R - Y MOD.
B - Y MOD.
Burst flag pulse
(BFP)
V
CC
6
75Ω
15
+
220µ
75
YOUT
measurement point
75
F•F
1
7
2
Color subcarrier
4.7k
SW1
0.1µ
8
560
14
Y/C
MIX
FILTER
75Ω
13
+
220µ
75
VOUT
measurement point
75
9
GND
12
75
COUT
measurement point
75
0.47µ
10
75Ω
GND
11
4
Multimedia ICs
BA7232FS
•
Circuit operation composite synch input. During low
(1) SYNCIN is for
input, the synchronization signal is output to YOUT,
VOUT and SYNCOUT.
(2) BFP is for burst flag pulse input. During low input,
the burst signal is output to pins CO and VO. When the
IC is set to PAL, it is this signal that directs the phase
inversion of the chroma signals. This signal also con-
trols the timing of the pedestal clamps of RIN, GIN and
BIN. During low input, the pedestal levels of RIN, GIN
and BIN are kept constant by charging an attached
capacitor.
(3) NT / PAL is the NTSC / PAL selector pin, and con-
nects to V
CC
when set to NTSC and to GND when set
to PAL.
(4) SCIN is for color subcarrier input. Set input to a
pulse wave or sine wave (3.579545MHz for NTSC and
4.433619MHz for PAL).
(5) COUT and YOUT are for output of chroma signals
and luminosity signals, respectively. Because the chro-
ma signal and luminosity signals can be output sepa-
rately, the IC can be adapted for S pins. Each has a
75Ω driver.
(6) VOUT is for color TV signal output, and has an
internal 75Ω driver.
(7) ROUT, GOUT and BOUT are for analog RGB sig-
nal output, and have an internal 75Ω driver.
The relationship between chroma phase and burst phase during PAL processing is as follows.
NT / PAL
BFP
Chroma phases
burst
B-Y
R-Y
B-Y
B-Y
burst
R-Y
burst
R-Y
5
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