Datasheet BH7634AS Datasheet (ROHM)

1

Multimedia ICs

Audio / video switch for CANAL - Plus
decoder

BH7634AS

The BH7634AS is one-chip IC that contains audio and video switches that support 21-pin SECAM and PAL connec­tors.
The I

2

C BUS for switch control simplifies applications, while the two expansion ports allow up to two external inputs.

•

Applications

VCRs

•

Features

1) I

2

C BUS control.

2) Video input is sync tip clamped, and includes a
small-capacity (0.022µF) input capacitor.

3) Three FSCOUT values.

4) Two expansion ports.

5) Audio mute function.

6) 75Ω driver output (pins 20 and 23) requires no
attached capacitor.

•

Absolute maximum ratings (Ta = 25°C)

Power supply voltage
Power dissipation
Operating temperature
Storage temperature

∗

Reduce by 12mW for each increase in Ta of 1°C over 25°C.

Parameter Symbol Limits Unit

V

CC 13.5 V

Pd

1200

mW
Topr – 25 ~ + 60 °C
Tstg – 55 ~ + 125 °C

•

Recommended operating conditions (Ta = 25°C)

Parameter

V

CC 8.5 13 V12

Symbol Min. Typ. Max. Unit

Operating power supply voltage

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Multimedia ICs BH7634AS

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Block diagram

VEDC IN

1

DRVGND

2

VTUNIN

3

DRVV

CC

4

VEXTIN

5

GND

6

ADECIN

7

FSCOUT

8

AEXTIN

9

AUXCTL1

10

ATUNIN

11

AUXCTRL2

AUXCTL2

AUXCTL2

FOR SW

I

2

C BUS

CONTROL

AUXCTL1

AUXCTL1

CURRENT

LIMITER

6.0V
REG

V

CC

VCC

12

VVTRIN

24

VEXTOUT

DRIVER

DRIVER

BUFFER

BUFFER

BUFFER

BUFFER

BUFFER

23

VVTROUT

22

VVPSOUT

21

VDECOUT

20

V

CC

19

AVTRIN

18

AEXTOUT

17

AVTROUT

16

ADECOUT

15

SCL

14

SDA

13

A

B

VSW1

A

B

C

VSW2

A
B

C

VSW3

A

B

ASW1

A
B

C

ASW2

A
B

C

ASW3

MUTE

6dB

6dB

CLAMP

CLAMP

CLAMP CLAMP

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Multimedia ICs BH7634AS

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Pin descriptions

Pin No.

3
4

2

1

VTUNIN
DRVV

CC

5 VEXTIN
6 GND
7 ADECIN
8 FSCOUT

9 AEXTIN
10 AUXCTL1
11 ATUNIN
12 AUXCTL2
13 SDA
14 SCL
15 ADECOUT
16 AVTROUT
17 AEXTOUT
18 AVTRIN
19 V

CC

20 VDECOUT
21 VVPSOUT
22 VVTROUT
23 VEXTOUT
24 VVTRIN

DRVGND

VDECIN

Composite video signal input (sink chip clamp).
The driver power supply. Not internally connected to V

CC (pin 19).

The driver ground. Not internally connected to the ground (pin 6).

Pin name

Composite video signal input (sink chip clamp).
Ground
Audio signal input.
Outputs one of three values (11.8V, 5.9V or 0.2V) as controlled by the I

2

C BUS.
Audio signal input.
Open collector. Normally pulled up to roughly 10k.
Audio signal output.
Open collector. Normally pulled up to roughly 10k.
I

2

C BUS Serial Data input.

I

2

C BUS Serial Clock input.
Audio output.
Audio output.
Audio output.
Audio input.
Power supply.
Composite video signal output.
Composite video signal output.
Composite video signal output.
Composite video signal output.
Composite video signal input (sink chip clamp).

Composite video signal input (sink chip clamp).

Function

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Multimedia ICs BH7634AS

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Pin descriptions and input output equivalent circuits

50µA

1k

50µA

1k

50k

DRVGND

GND

DRVVCC

VCC

50k

6V

12V

FS control

Three voltages are output
via I

2

C BUS control: 11.8V,

5.9V, 0.2V.

8 FSCOUT

—

™ —

Pin No.

1

3

5

24

VDECIN

VTUNIN

VEXTIN

VVTRIN

26DRVGND

GND

419DRVV

CC

VCC

7

9

11

18

ADECIN

AEXTIN

ATUNIN

AVTRIN

™ — 1.6V

—— 0V

— — 12V

™ — 5.3V

IN OUT

Pin name

Typ.

voltage

I / O equivalent circuits Pin description

Video signal input

For composite video signal
input (sink chip clamp input).

Ground

DRVGND is the driver
ground. GND is the ground
for the circuit itself. GND and
DRVGND are not connected
internally.

Power supply

DRVV

CC is the driver

power supply. V

CC is the

power supply for the circuit
itself. V

CC and DRVVCC

are not connected internally.

Audio signal input

For audio signal input.
Input impedance is 50k.

5

Multimedia ICs BH7634AS

50µA

100

50µA

1k

Pin name

External control

An open collector. Normally
pulled up with a (roughly)
10kΩ resistor.

I

2

C BUS data input

For serial data input
compliant with the I

2

C BUS.

I

2

C BUS clock input

For clock input compliant
with the I

2

C BUS.

Typ.

voltage

I / O equivalent circuits Pin description

Pin No.

1012AUXCTL1

AUXCTL2

13 SDA

14 SCL

—

™ —

™ ——

™ ——

IN OUT

500µA

1517ADECOUT

AEXTOUT

16

AVTROUT

— ™ 6V

—

™ 5.3V

Audio signal output

Outputs the audio signal.
ADECOUT and AEXTOUT
are respectively for decoder
output and external output.

Audio signal output

Outputs the audio signal.
AVRTOUT outputs to the
signal processor.

6

Multimedia ICs BH7634AS

1mA

Pin No.

2023VDECOUT

VEXTOUT

2122VVPSOUT

VVTROUT

—

™ 1.7V

—

™ 1.0V

IN OUT

Pin name

Video signal output

Outputs the composite
video signal. VDECOUT and
VEXTOUT are respectively
for decoder output and
external output.

Video signal output

Outputs the composite video
signal. VVPSOUT is output for
VPS, VVTSOUT outputs to
the signal processor.

Typ.

voltage

I / O equivalent circuits Pin description

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Multimedia ICs BH7634AS

Parameter Symbol Min. Typ. Max. Unit Conditions

I

CC 30 46 62 mA

V

FSCH 11.0 11.8 12.0 V RL = 10kΩ

V

FSCM 5.2 5.9 6.8 V RL = 10kΩ

V

FSCL 0 0.2 1.0 V RL = 10kΩ

I

FSC — — 20 mA VFSCO = 0V

I

SYN 1.0 — — mA RL = 10kΩ

V

AUXL 0 0.2 1.0 V RL = 10kΩ

G

VV – 1 0 1 dB VIN = 1VP-P, f = 4.43MHz

V

F – 3 0 1 dB VIN = 1VP-P, f = 100k / 7MHz

G

VA – 1 0 1 dB VIN = 1Vrms, f = 1kHz

V

OMA 3.0 3.6 — Vrms f = 1kHz, THD = 0.5%

THD — 0.005 0.1 % V

IN = 1Vrms, f = 1kHz

V

Min. — 20 100 µVrms DIN AUDIO Rg = 600Ω

Z

IN 40 50 60 kΩ

∆V

OF — — 20 mV

V

H 3.0 — — V

V

L 0 — 1.5 V

〈Device〉

Supply current
FSCOUT voltage, H
FSCOUT voltage, M
FSCOUT voltage, L
FSCOUT restriction current
External controller sink current
External controller voltage, L

〈Video switches〉

Voltage gain
Frequency characteristics

〈Audio switches〉

Voltage gain
Maximum output level
Total harmonic distortion
Input conversion noise voltage
Input impedance
Offset voltage

〈Control〉

"H" level voltage
"L" level voltage

Note: Supports I2C BUS input.

No signal

•

Electrical characteristics (unless otherwise noted, Ta = 25°C, VCC = 12V)

〈Video switches〉

Interchannel crosstalk
Secondary harmonics
Tertiary harmonics

〈Audio switches〉

Interchannel crosstalk
Mute attenuation

Parameter

Symbol

Min. Typ. Max. Unit Conditions

CT

V — – 70 – 50 dB VIN = 1VP-P, f = 4.43MHz

HD

2 — – 45 – 40 dB VIN = 1VP-P, f = 4.43MHz

HD

3 — – 50 – 45 dB VIN = 1VP-P, f = 4.43MHz

CT

A — – 90 – 70 dB VIN = 1Vrms, f = 1kHz

V

MTA — – 90 – 70 dB VIN = 1Vrms, f = 1kHz

•

Guaranteed design parameters (unless otherwise noted, Ta = 25°C, VCC = 12V)

8

Multimedia ICs BH7634AS

Parameter Symbol

Min. Max.

Unit Conditions

f

SCL kHz

µs

t

BUF

tSU: STA µs

t

HD: STA µs

t

LOW

tHIGH

µs
µs

t

SU: DAT ns

t

R ns

t

F ns

t

SU: STO

0

4.7

4.7

4.0

4.7

4.0

250

—
—

4.0

100

—

—

—
—
—

—

1000

300

— µs

SCL clock frequency
Data transfer waiting time
Start holding time
SCL“L”, holding time
SCL“H”, holding time
Start setup time
Data setup time
Signal rise time
Signal fall time
Stop setup time

•

Recommended I2C BUS operating conditions

SDA

SCL

P

t

BUF

t HD: STA t LOW t HIGH t SU: DAT t SU: STA S r t SU: STO P

t

R t F

S

I2C BUS control signal

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Multimedia ICs BH7634AS

S

1

D9D8D7D6D5D4D3D2 D1D0000000

0000010

MSB

MSB

S

SLAVE ADDRESS::

A

DATA1 , 2

:
:

LSB MSB LSB

LSB

SLAVE ADDRESS

A DATA1 A DATA2 A P

I

2

C BUS format

Start condition
Slave address

Confirmation response clock pulse
Data byte

1st byte 2nd byte

•

I2C BUS control input

D9 SELECT

H
L

A
B

SW1

D8 SELECT

H

L

A
HA
LB

C

D7

H
L
H
L

SW2

D6 SELECT

H

L

A
HA
LB

C

D5

H
L
H
L

SW3

D4 FSC OUT

H

L

LOW
H MIDDLE
L HIGH

HIGH

D3

H
L
H
L

FSCOUT control

D1 AUX CTL1 OUT

H
L

HIGH

LOW

External control 1

D0 AUX CTL2 OUT

H
L

HIGH

LOW

External control 2

D2 MUTE

H
L

MUTE

NORMAL

MUTE control

•

Switch input and mode selection

Note: When D2 is HIGH, only the audio switches are
muted.

10

Multimedia ICs BH7634AS

1234567891011

AUXCTL2

AUXCTL2

FOR SW

I

2

C BUS

CONTROL

AUXCTL1

AUXCTL1

CURRENT

LIMITER

6.0V
REG

V

CC

CLAMPCLAMPCLAMP

V

CC

12

V

CC

24

DRIVER

DRIVER

BUFFER

BUFFER

BUFFER

BUFFER

BUFFER

23 22 21 20 19 18 17 16 15 14 13

CLAMP

AB

VSW1

ABC

VSW2

ABC

VSW3

AB

ASW1

ABC

ASW2

ABC

ASW3

MUTE

6dB 6dB

A

V

A

VVVV

A

VV

A

SG4

12

SW24

SW19

SW18

DRVV

CC

I2C BUS

SG

VCC

12 3

SG8

0.022µ

470µ

100µ

75Ω

1k

100µ

1k

47µ

1k

47µ

10k

47µ

1k

10k

5V

10k

5V

75Ω

470µ

20µ

47µ

47µ

75Ω

600

75Ω

10k

VCC

10k

10k

SW11

123

SG7

20µ

47µ

47µ

600

SW9

SW8

12

12

3

SG6

20µ

47µ

47µ

600

SW7

123

SG6

20µ

47µ

47µ

600

SG3

12

SW5

0.022µ

SG2

12

SW3

DRVV

CC

0.022µ

SG1

12

SW1

0.022µ

Fig. 1

•

Measurement circuit

11

Multimedia ICs BH7634AS

123

V

CC

,

45678910

V

CC

11

AUXCTL2

AUXCTL2FOR SW

I

2

C BUS

CONTROL

AUXCTL1

AUXCTL1

CURRENT

LIMITER

6.0V
REG

V

CC

CLAMPCLAMPCLAMP

V

CC

12

VTRIN

0.022µF

100µF

100µF

47µF

47µF

47µF

47µF

75Ω

75Ω

24

EXT OUT

DRIVER

DRIVER

BUFFER

BUFFER

BUFFER

BUFFER

BUFFER

23

VTR OUT22VPS OUT21DECODER OUT

20

V

CC

19

VTR IN18EXT OUT17VTR OUT16DECODER OUT

15 14 13

CLAMP

AB

VSW1

ABC

VSW2

ABC

VSW3

AB

ASW1

ABC

ASW2

ABC

ASW3

MUTE

6dB 6dB

MICROCONTROLLERS

47µF

47µF

47µF

47µF

47µF

0.022µF

1µF

100µF

0.1µF

1µF

0.022µF

0.022µF

TUNER IN

EXT IN2

EXT IN1

10kΩ

10kΩ

TO 21PIN CONNECTOR

DECODER IN

75Ω

EXT IN2

EXT IN1

TUNNER IN

DECODER IN

75Ω

75Ω

Fig. 2

•

Application example

12

Multimedia ICs BH7634AS

– 25

0

25

100k 1M 10M 100M

FREQUENCY: f

(Hz)

GAIN: g (dB)

Fig. 3 Video output (pins 20, 23) frequency

characteristics

– 25

0

25

1k 10k 100k 1M 10M

FREQUENCY: f

(Hz)

GAIN: g (dB)

Fig. 6 Audio output (pin 16) frequency
characteristics

– 25

0

25

100k 1M 10M 100M

FREQUENCY: f

(Hz)

GAIN: g (dB)

Fig. 4 Video output (pins 21, 22) frequency

characteristics

– 25

0

25

1k 10k 100k 1M 10M

FREQUENCY: f

(Hz)

GAIN: g (dB)

Fig. 5 Audio output (pins 15, 17) frequency
characteristics

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Electrical characteristic curves

SDIP24

0.51Min.

6.5 ± 0.3

0.3 ± 0.1

7.62

3.4 ± 0.2

22.9 ± 0.3

0.5 ± 0.11.778

13

12

24

1

3.95 ± 0.3

0° ~ 15°

•

External dimensions (Units: mm)