ROHM BH3866AS Datasheet

1

Video ICs

Dual-line serial control sound processor IC

BH3866AS

The BH3866AS is a signal processing IC developed for the control of volume and tone quality in TV equipment. Since dual-line serial control (I

2

C BUS) is used, the volume level and tone quality in TV equipment can be changed

using signals such as those from a microcomputer or similar device.

•

Applications

DVDs, personal computers, high-vision TVs, karaoke sets, digital broadcasts, CATVs, and other TV equipment

•

Features

1) 3-channel volume and sound quality control (for stereo and center speakers).

2) Absorption of volume deviation between input sources and improved S / N ratio, for better sound quality, using an AGC circuit.

3) Control through I

2

C BUS serial control.

4) Internal pseudo-stereo circuit provides phase-shift matrix surround effect.

•

Recommended operating conditions (Ta = 25°C)

•

Absolute maximum ratings (Ta = 25°C)

Parameter

Symbol

Min. Typ. Max. Unit

Power supply voltage

V

CC

7.0 — 9.5 V

Parameter Symbol Limits Unit

Power supply voltage V

CC 10.0 V

Power dissipation 1250

∗

mW Operating temperature Topr °C Storage temperature Tstg °C

Pd

– 25 ~ + 75

– 55 ~ + 125

∗

Reduced by 12.5mW for each increase in Ta of 1°C over 25°C.

2

Video ICs BH3866AS

•

Pin descriptions

Pin No. Pin name Function

1

R

IN

Rch input

Pin No. Pin name Function

17

DAC

Expansion DAC (L / H)

2

GND

Ground

18

SCV

Vol Cch shock sound integration

3

AGCADJ

AGC 0dB adjustment

19

C

OUT

Cch output

4

LS1

AGC level sensor 1

20

L

OUT

Lch output

5

LS2

AGC level sensor 2

21

CB

Cch Bass fc setting

6

S

OUT

Sch output pin and LPF

22

CT

Cch Treble fc setting

7

PS

Phase shift pin (internal resistance: 18kΩ)

23

LB

Lch Bass fc setting

8

Vref

1 / 2 V

CC

24

LT

Lch Treble fc setting

9

STB

Bass shock sound integration

25

STT

Treble shock sound integration

10

RT

Rch Treble fc setting

26

BGAIN

Bass Mix Gain adjustment

11

RB

Rch Bass fc setting

27

MS

IN

Mono Sur input

12

R

OUT

Rch output

28

B

IN

Bass detection LPF operating amplifier input

13

SRV

Vol Rch shock sound integration

29

ADD

L + R added output after AGC

14

SLV

Vol Lch shock sound integration

30

C

IN

Cch input

15

SCL

I

2

C communications clock

31

V

CC

Power supply, 9V

16

SDA

I

2

C communications data

32

L

IN

Lch input

•

Block diagram

32

1

17

16

LINRIN31VCCGND30CINAGCADJ29ADDLS128BINLS227MSINSOUT26BGAINPS25STTVref24LTSTB23LBRT22CTRB21CBROUT20LOUTSRV19COUTSLV

18

23456789101112131415

SCVSCL

DACSDA

+

–

+

–

+

–

+

–

+

–

+

–

+

–

+

–

+

–

+

–

VCA

CIN

AGC

MIX OFF

MIX ON

BASS

OFF

Surr effect

ON

OFF

ON

OFF

ON

OFF

ON

SON

OFF

ON

SSTE

LOOP

L + R

CSEL

SMON

A G C

L + R

PHASE

SHIFT

L + S

10k

50k

10k

50k

10k

VCA

R - S

L - R

LFP

AMP

+

–

VCC

1 2

V

CC

I2C BUS

SCL SDA

interface

IncrementIncrement

Volume VolumeVolume

Volume Volume Volume

Tone

(bass / treble)

Tone

(bass / treble)

Tone

(bass / treble)

3

Video ICs BH3866AS

•

Input / output circuits

Pin No.

Input pins.

30 4.5V 50k

—

IC

IN

32 LIN

1RIN

Pin name I / OZin

Pin voltage

Equivalent circuit Function

AGC 0dB adjustment pin. This pin is connected to the base of PNP. The current output from this pin is 1µA (Typ.) Max.

3—IAGCADJ

Output pins.

19 4.5V OC

OUT

20 LOUT

12 ROUT

Time constant pin on the side that suppresses the AGC signal level.

4———LS1

VCC

GND

50k

1 2

V

CC

VCC

GND

200

10k

VCC

GND

VCC

GND

200

430

2k

4

Video ICs BH3866AS

Pin No.

5———LS2

Pin name I / OZin

Pin voltage

Equivalent circuit Function

7PS

Serves as both the output pin for the surround and pseudostereo effects, and the LPF pin.

For the phase-shifter filter for the surround and pseudostereo effects.

6 4.5V 10k OS

OUT

1 / 2 VCC. This voltage serves as the power supply for the signal system.

Time constant pin on the side that amplifies the AGC signal level.

8 4.5V ——Vref

———

VCC

GND

200

20k

2k

VCC

GND

200

10k

VCC

GND

10k 18k

10k

18k

50k

VCC

GND

5

Video ICs BH3866AS

Pin No.

Pin name I / OZin

Pin voltage

Equivalent circuit Function

Treble filter pins for the left, right, and center channels.

Integration pins that prevent shock sound when switching the bass and treble levels.

25

——

—

30k

STT

9 STB

22 4.5V 30kCT

24 LT

10 RT

Bass filter pins for the left, right, and center channels.

21 4.5V 30kCB

23 LB

11 RB

Integration pins that prevent shock sound when switching the volume levels on the left, right, and center channels.

14 — —30kSLV

18 SCV

13 SRV

VCC

GND

30k

DAC

VCC

GND

30k

1 2

V

CC

VCC

GND

30k

1 2

V

CC

VCC

GND

30k

DAC

6

Video ICs BH3866AS

VCC

GND

Pin No.

SCL pin for the I

2

C BUS.

This is the clock pin.

15 — — ISCL

Pin name I / OZin

Pin voltage

Equivalent circuit Function

50k

1 2

V

CC

17 0 / 5 ODAC

VCC

GND

200

100k

25.6k

74.6k

16 — —

—

——

ISDA

Gain adjustment pin used to mix the bass on the left and right channels.

26 4.5VBGAIN

VCC

GND

control logic

SDA pin for the I2C BUS. The Acknowledge signal is output from this pin. This is the data pin.

0V and 5V output pin that enables control with the I

2

C BUS.

VCC

GND

B

IN

10k

7

Video ICs BH3866AS

Pin No.

Surround input section for monaural signals in the surround section.

Bass signal input to the left and right channels.

27 4.5V 50k IMS

IN

Pin name I / OZin

Pin voltage

Equivalent circuit Function

50k

1 2

V

CC

29 4.5V OADD

28 4.5V 50k IB

IN

Power supply pin.

Ground pin.

31 9VV

CC

20VGND

Incremented output from the left and right channels following AGC.

VCC

GND

BGAIN

50k

1 2

V

CC

10k

1 2

V

CC

VCC

GND

VCC

GND

200

10k

—

—— —

——

8

Video ICs BH3866AS

•

Electrical characteristics (unless otherwise noted, Ta = 25°C, VCC = 9V, f = 1kHz, Rg = 600Ω, RL = 10kΩ)

Parameter

Symbol Conditions

IQQuiescent circuit current VIN = 0Vrms

VOMRMax. output voltage, Rch Max. output voltage, Lch Max. output voltage, Cch

VOML

Min.

—

2.1

Typ.

35

2.5

Max.

65 — —

Unit

mA Vrms Vrms

f

INR = 1kHz, VIN = 1Vrms, RINR =

THD = 1%( )

( / V

IN)

( / V

IN)

( / V

IN)

GVRVoltage gain, Rch Voltage gain, Lch Voltage gain, Cch

– 1.5 0 1.5 dB V

IN = 1Vrms, GVR = 20log

GVL – 1.5 0 1.5 dB VIN = 1Vrms, GVL = 20log

GVC – 1.5 0 1.5 dB VIN = 1Vrms, GVC = 20log

VOMC 2.1 2.5 — Vrms THD = 1%( )

THDR

Total harmonic distortion, Rch Total harmonic distortion, Lch Total harmonic distortion, Cch

THDL

——0.01

0.01

0.1

0.1%%

VIN = 1Vrms V

IN = 1Vrms

THDC — 0.1 0.3 % VIN = 1Vrms

VNOROutput noise voltage, Rch Output noise voltage, Lch Output noise voltage, Cch

VNOL

— —35357070

µVrms µVrms

Rg = 0Ω, DIN AUDIO Rg = 0Ω, DIN AUDIO

VNOC —3570µVrms Rg = 0Ω, DIN AUDIO

VMNORResidual noise voltage, Rch Residual noise voltage, Lch Residual noise voltage, Cch

VMNOL

— —

331010µVrms

µVrms

Rg = 0Ω, DIN AUDIO Rg = 0Ω, DIN AUDIO

VMNOC —310µVrms Rg = 0Ω, DIN AUDIO

(

R / L)

50k ×

(1 – )

CTR-LCrosstalk, Rch→Lch Crosstalk, Rch→Cch Crosstalk, Lch→Rch Crosstalk, Lch→Cch Crosstalk, Cch→Rch Crosstalk, Cch→Lch

Input impedance, Rch

Input impedance, Lch

Input impedance, Cch

70 78 — dB V

IN = 1Vrms, CTR-L = 20log

CTR-C 70 78 — dB VIN = 1Vrms, CTR-C = 20log

CTL-R 70 78 — dB VIN = 1Vrms, CTL-R = 20log

CTL-C 66 71 — dB VIN = 1Vrms, CTL-C = 20log

CTC-R 70 78 — dB VIN = 1Vrms, CTC-R = 20log

CTC-L 70 78 — dB

R

INR 35 50 65 kΩ

f

INL = 1kHz, VIN = 1Vrms, RINR =

RINL 35 50 65 kΩ

f

INC = 1kHz, VIN = 1Vrms, RINR =

fOUTR = 1kHz, ROUTR =

1k ×

1 –

Output impedance, Rch

Output impedance, Lch

Output impedance, Cch

ROUTR —50Ω

f

RR = 100Hz,

V

RR = 100mVrms,

VRR

Ripple rejection, Rch

Ripple rejection, Lch

Ripple rejection, Cch

RRR 40 53 — dB

f

OUTL = 1kHz, ROUTL =

1k ×

ROUTL —50Ω

f

OUTC = 1kHz, ROUTC =

1k ×

ROUTC —

—

—50 Ω

RINC 35 50 65 kΩ

V

IN = 1Vrms, CTC-L = 20log

RR

R = 20log

VIN

Muting level, Rch

Muting level, Lch

Muting level, Cch

VMUTER 80 90 — dB

V

IN = 1Vrms, VMUTER = 20log

VIN

VMUTEL 80 90 — dB

V

IN = 1Vrms, VMUTEL = 20log

f

RR = 100Hz,

V

RR = 100mVrms,

VRR

RRL 40 53 — dB

RR

R = 20log

VIN

VMUTEC 80 90 — dB

V

IN = 1Vrms, VMUTEC = 20log

f

RR = 100Hz,

V

RR = 100mVrms,

VRR

RRC 40 53 — dB

RR

R = 20log

THD = 1%( )

(

R / C)

(

L / R)

( L / C) (

C / R)

(

C / L)

50k ×

(1 – )

50k ×

(1 – )

C

B

BB

A

D D D D

D D

B