ROHM BH7240AKV Datasheet

1

Multimedia ICs

Color TV signal encoder

BH7240AKV

The BH7240AKV is an IC that converts digital RGB signals (8-bit) to NTSC and PAL color TV signals. In addition to
composite output, luminance output, chrominance output, and analog RGB output are available. Each type of output
is equipped with an internal 75Ω driver.

•

Applications

TV peripheral devices

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Block diagram

36 35 34 33 32 31 30 29 28 27 26 25

123456789101112

24

23

22

21

20

19

18

17

16

15

14

13

RDATA0

RDATA1

RDATA2

RDATA3

DV

DD

RDATA4

RDATA5

RDATA6

RDATA7

SCIN

SYNCIN

NT / PAL

37

38

39

40

41

42

43

44

45

46

47

48

BDATA3

BDATA2

BDATA1

BDATA0

VCLK

DGND

VREFOUT

N.C.

AGND1

RCLAMP

V

CC1

GCLAMP

BCLAMP

GND2

R

OUT

GOUT

BOUT

YOUT

COUT

VOUT

VCC2

YTRAP

N.C.

N.C.

BDATA4

BDATA5

BDATA6

BDATA7

GDATA0

GDATA1

GDATA2

GDATA3

GDATA4

GDATA5

GDATA6

GDATA7

DECODER

LATCH

CLAMP CLAMP

MATRIX

LPF

BPF6dB6dB6dB6dB

75

GND V

CC

VCC

GND

GND

CLK

75 75 75 75 75

YTRAP

Y / C

MIX

Burst

Flag

GEN.

CLAMP

VREF

CELL

MATRIX

CELL

MATRIX

CELL

MATRIX

DECODER DECODER

CLK

LATCH

CLK

LATCH

CLK

SYNC

CHROMA

GEN.

SYNC

ADD.

V

CC

SYNC

8

8

8

R-Y B-Y

Y

R

G

B

SYNC

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Features

1) Supports both NTSC and PAL.

2) Internal RGB3-channel DAC (internal regulator).

3) Internal burst timing generator circuit.

4) Y / C separation output pin.

5) Analog RGB signal output pin.

3) Internal 75Ω driver.

2

Multimedia ICs BH7240AKV

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Absolute maximum ratings (Ta = 25°C)

∗

1 At Ta = 25°C

∗

2 Reduced by 9.0mW for each increase in Ta of 1°C over 25°C.

(When mounted on a 70mm × 70mm × 1.6mm glass epoxy board.)

Parameter

Symbol Limits Unit

Power supply voltage 7

∗

1

V

Power dissipation 900

∗

2

mW

Operating temperature Topr

– 20 ~ + 70

°C

Storage temperature Tstg – 55 ~ + 125 °C

Pd

DV

DD, AVCC1

AV

CC2

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Recommended operating conditions (Ta = 25°C)

Parameter Symbol Limits

4.50 ~ 5.50

Unit

Power supply voltage V

DV

DD, AVCC1

AV

CC2

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Recommended input conditions (at DVDD = AVCC1 = AVCC2 = 5.0V)

Parameter Symbol

VTH

VTL

VTH

VTL

Limits Unit

VCLK, RGBDATA
input high level

VCLK, RGBDATA
input low level

SYNCIN, NT / PAL
input high level

SYNCIN, NT / PAL
input low level

2.2 ~ 5.0

GND ~ 0.8

2.2 ~ 5.0

GND ~ 0.8

V

V

V

V

3

Multimedia ICs BH7240AKV

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Pin descriptions

Pin No.

1
2
3
4

5
6
7
8

9

11
12
13

14

15
16

17
18
19
20
21

22
23
24

10

25
26
27

28
29

30
31
32
33
34
35
36
37
38
39

Pin name
BCLAMP

AGND2

R

OUT

GOUT
BOUT
YOUT
COUT
VOUT

AVCC2

YTRAP

N.C.
N.C.

NT / PAL

SYNCIN

SCIN

RDATA7
RDATA6
RDATA5
RDATA4

DV

DD

RDATA3
RDATA2

RDATA1
RDATA0
GDATA7
GDATA6
GDATA5
GDATA4

GDATA3
GDATA2
GDATA1
GDATA0
BDATA7
BDATA6
BDATA5
BDATA4
BDATA3
BDATA2
BDATA1

Analog blue signal clamping pin
GND pin for 75Ω driver
Analog red signal output. Internal 75Ω driver
Analog green signal output. Internal 75Ω driver

Analog blue output. Internal 75Ω driver
Luminance signal output. Internal 75Ω driver
Chrominance signal output. Internal 75Ω driver
Composite video signal output. Internal 75Ω driver
Power supply pin for 75Ω driver

This pin is not connected within the IC.
This pin is not connected within the IC.
Video output method selector pin. NTSC when HIGH, PAL when LOW

Function

Red data input pin (bit 7)
Red data input pin (bit 6)
Red data input pin (bit 5)

Power supply pin for digital circuit
Red data input pin (bit 3)

Red data input pin (bit 2)
Red data input pin (bit 1)
Red data input pin (bit 0)

Red data input pin (bit 4)

Green data input pin (bit 7)
Green data input pin (bit 6)
Green data input pin (bit 5)
Green data input pin (bit 4)
Green data input pin (bit 3)

Green data input pin (bit 2)
Green data input pin (bit 1)
Green data input pin (bit 0)
Blue data input pin (bit 7)
Blue data input pin (bit 6)
Blue data input pin (bit 5)
Blue data input pin (bit 4)
Blue data input pin (bit 3)
Blue data input pin (bit 2)
Blue data input pin (bit 1)

Luminance trap filter connection pin. Connecting a trap filter eliminates the chrominance
band component included in the luminance signal, and reduces the amount of chrominance
color. Output impedance is approximately 2kΩ. This is effective only for composite video
output.

Composite SYNC input. For LOW input, SYNC is output to YOUT and VOUT. At the same
time, DC clamping of the RGB signal takes place.

Color subcarrier input. Sine waves of a frequency corresponding to the required output method,
or pulse waves with a duty of 50%, should be input in a range not exceeding V

CC-GND.