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MITSUMI
RGB Encoder
Monolithic IC MM1268
Outline
This IC converts analog RGB signals into chroma, Y+S and composite video signals.
Features
1. Operates on 5V single power supply
2. Supports NTSC and PAL formats
3. Supports S (Y, C output)
4. 75Ω driver output (RGB output, Y, C output, composite video output)
5. Built-in BRF and delay circuits
Package
SOP-24A
RGB Encoder MM1268
Applications
1. PCs
2. Game equipment
3. Other video equipment
Equivalent Circuit Diagram
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MITSUMI
RGB Encoder MM1268
Pin Description
Pin no. Pin name Function Internal equivalent circuit diagram
1 GND1
2 RIN
3 GIN
4 BIN
RGB input pins
Maximum input voltage is 1V
DC level is 2V during clamp
P-P
5 NC
6 SC
IN
7 NTSC/PAL
8 BFPOUT
OPEN
Subcarrier input pin
Input a 0.4V~5V
P-P sine wave
Mode setting pin
NTSC : V
CC
PAL : GND
Burst flag pulse monitor pin
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MITSUMI
RGB Encoder MM1268
9 Yclp
10 SYNCIN
11 NC
12 VCC1
13 Iref
Connects to capacitor for Y signal
clamp
Composite sync signal input pin
OPEN
Determines internal reference
14 Vref
current
Connect a 47kΩ resistor between
this pin and ground
Internal reference voltage pin
Reference voltage is 4V
Connect a 10µF capacitor between
this pin and ground.
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MITSUMI
RGB Encoder MM1268
15 COUT
16 YOUT
17 Ytrp
Chroma signal output pin
Luminance signal output pin
Able to drive 75Ω load
Connects to trap for removing
subcarrier frequency component
in VIDEO output luminance signal
18 f0
19 VCC2
20 VIDEO OUT
Determines filter and delay circuit
f0
NTSC : 20k
PAL : 16k
Output stage power supply
Composite video signal output pin
Able to drive 75Ω load
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MITSUMI
RGB Encoder MM1268
21 BOUT
22 GOUT
23 ROUT
24 GND2
RGB signal output pin
Able to drive 75Ω load
Output stage GND
Absolute Maximum Ratings
Item Symbol Ratings Units
(Ta=25°C)
Storage temperature T
Operating temperature T
Power supply voltage V
Allowable loss Pd
Note : *1 Loss tolerance when garaepo board is mounted. (25.0 75.0 0.8mm garaepo board)
CC max. +7 V
Recommended Operating Conditions
Item Symbol Ratings Units
Operating temperature T
Operating voltage VOP 4.75~5.25 °C
STG
OPR
1 720 mW
*
OPR
-
40~+125 °C
-
20~+75 °C
-
20~+75 °C
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MITSUMI
RGB Encoder MM1268
Electrical Characteristics
Item
Consumption current 1 I
Consumption current 2 I
RGB output characteristics R
R output voltage VR F
G output voltage VG E
B output voltage VB D
Rf characteristic fR F
Gf characteristic fG E
Bf characteristic fB D
Brightness output characteristic Y
(Ta=25°C, VCC=1, 2=5V)
Symbol
Measurement
circuit
CC1 V4 : SG6 V5 : SG8 31 40 mA
CC2 SW conditions (0, 0, 0, 0, 0, 0, 0) 17 22 mA
OUT, GOUT, BOUT
OUT, VIDEOOUT
Measurement conditions,
SW conditions Min. Typ. Max. Units
(S1, S2, S3, S4, S5, S6, S7)
V1, 2, 3 : SG1
SW conditions (1, 1, 0, 0, 1, 1, 0)
V1, 2, 3 : SG2/SG1
SW conditions (1, 1, 0, 0, 1, 1, 0)
0.64 0.71 0.78 V
-
3.0 dB
Sync level Y(S) 0.26 0.29 0.33 VP
Red brightness level Y(R) V1 : SG3 V2 : SG4 V3 : SG5 0.17 0.21 0.26 V
Green brightness level Y(G) B/C V4 : SG6 V5 : SG8 0.35 0.42 0.49 V
Blue brightness level Y(B) SW conditions (1, 0, 0, 0, 0, 0, 0) 0.065 0.08 0.095 V
White brightness level Y(W) 0.6 0.71 0.82 V
fY(R)
Brightness f characteristic fY(G) B/C
fY(B)
Chroma output characteristic C
OUT, VIDEOOUT
V1, 2, 3 : SG2/SG1
SW conditions (1, 1, 0, 0, 1, 1, 0)
-
3.0 dB
NTSC
Burst level CL(b) 0.2 0.25 0.3 V
Red level ratio CL(R) 2.84 3.16 3.48
Red phase CP(R) V1 : SG3 V2 : SG4 V3 : SG5 94 104 114
Green level ratio CL(G) A/C V4 : SG6 V5 : SG8 2.65 2.95 3.25
Green phase CP(G) SW conditions (1, 0, 0, 0, 0, 0, 0) 231 241 251
Blue level ratio CL(B) 2.01 2.24 2.47
Blue phase CP(B) 337 347 357
PAL
Burst -1 level CL(b1) 0.2 0.25 0.3 V
Burst -1 phase CP(b1) 125 135 145
Burst -2 level CL(b2) 0.2 0.25 0.3 V
Burst -2 phase CP(b2) 215 225 235
Red-1 level ratio CL(R1) 2.84 3.16 3.48
Red-1 phase CP(R1) 94 104 114
Red-2 level ratio CL(R2)
Red-2 phase CP(R2)
Green -1 level ratio CL(G1)
A/C V4 : SG6 V5 : SG8
Green -1 phase CP(G1) 231 241 251
V1 : SG3 V2 : SG4 V3 : SG5
SW conditions (1, 0, 0, 1, 0, 0, 1)
2.84 3.16 3.48
246 256 266
2.65 2.95 3.25
Green -2 level ratio CL(G2) 2.65 2.95 3.25
Green -2 phase CP(G2) 109 119 129
Blue -1 level ratio CL(B1) 2.01 2.24 2.47
Blue -1 phase CP(B1) 337 347 357
Blue -2 level ratio CL(B2) 2.01 2.24 2.47
Blue -2 phase CP(B2) 3 13 23
NTSC/PAL
Burst position td
Burst width tw SW conditions (1, 0, 0, 1, 0, 0, 1) 2.5 2.75 3.2 µS
A/C
Carrier lea VL A/C
V1 : SG3 V2 : SG4 V3 : SG5 V4 : SG6
V1~3 : no signal, V4 : SG6
SW conditions (1, 0, 0, 1, 0, 0, 1)
0.4 0.6 0.75 µS
20
deg
deg
deg
deg
deg
deg
deg
deg
deg
deg
deg
mV
P-P
P-P
P-P
P-P
-
P-P
P
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MITSUMI
Input conditions
Symbol Signal
SG1 Sine wave, 1V
SG2 Sine wave, 1V
SG3 Color bar (100%) R signal
SG4 Color bar (100%) G signal
SG5 Color bar (100%) B signal
SG6 Sine wave, 0.5V
SG7 Sine wave, 0.5V
SG8 0.8V
-
2.0V, composite, sync signal
P-P, f=200kHz
P-P, f=5MHz
P-P, f=3.58MHz
P-P, f=4.43MHz
SG3
SG4
SG5
SG8
4.5µ
RGB Encoder MM1268
1V
0V
1V
0V
1V
0V
2V
0.8V
64µ
Measuring Circuit
SW conditions : (0,0,0,0,0,0,0) for the circuit illustrated below
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