NJM2256M NJR, NJM2256M Datasheet - Page 9

• Manufacturer Part Number: NJM2256M
• Description: IC VIDEO COLOR SUPRIMPOSER 20DMP
• Manufacturer: NJR
• Type: Signal Superimposerr

Specifications of NJM2256M

• Applications: Video
• Mounting Type: Surface Mount
• Package / Case: 20-DMP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

■ APPLICATION NOTES
1. Input Signal
superimposed color level.
2. Clamp Pulse
(Y, R-Y, B-Y) is to be fixed at the bias point within the IC.
Note) The pulse width of clamp pulse shall be set more than 3 µs. (see figure 2)
Ver.2004-02-17
I / O Explanation
● Control Pin Low=0V, HIGH=5V
● Adjusting Pin (Normally open → non adjustment)
Superimposed color level shall be determined by the following standard signal level.
During the interval of blanking, input the pulse through clamp pulse pin 20 the blanking level (0 level) of input signal
The character output standard level on the specification shall be determined through calculation out of 75% of
(In order to avoide the clipping of the encoding signal, the character output level is determined to lower level)
● The character output level converting expression
The basic expression
BF level
Inversion set up correction 18 Y inversion signal level adjusting pin.
Y
R - Y
B - Y
R 3
G 4
B 5
Character Pulse
HBF Pulse
C Inversion
Y Inversion
NTS / PAL Switch 14
Clamp Pulse
BLK Pulse
E
E
as in the following.
V
V
R
B
From standard level and practical input level, each color signal level imposed in R-Y, B-Y and Y signals are
V
R - Y
B - Y
- E
- E
E
Y
Y
(E
Y
Y
= 0.75 × 1 [V
= 0.75 × 0.7 [V
= 0.75 × 0.7 [V
= 0.375E
= - 0.088E
= 0.158E
= 0.30E
= 0.70E
= - 0.30E
R
, E
0.7V
1.0V
0.7V
G
, E
Superimposed color adjustment
R
P - P
P - P
P - P
R
19
10
R
R
B
+ 0.59E
- 0.59E
R
, LOW 0, HIGH 1)
R
- 0.316E
+ 0.310E
- 0.59E
- 0.174E
P - P
16
15
12
20
P-P
P - P
] × E
] × E
G
G
] × E
Color difference, brightness inverting pin
G
- 0.11E
+ 0.11E
G
G
+ 0.89E
R – Y
G
- 0.059E
13 Burst flag insert level adjusting pin.
+ 0.058E
B – Y
+ 0.263E
Y, R-Y, B-Y signal process pulse input
Y
/ 1
/ 1.4
/ 1.78
B
B
Flg. 2 Clamp Pulse Width
B
B
B
B
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