BH7800K-E

Video ICs

Single chip Hi-Fi audio signal

processor

BH7800K

The BH7800K incorporates the functions for a VHS audio signal processing system on a single chip. The circuits on

the chip are a peak-noise reduction processor (PNR), an FM modulator / demodulator circuit, an I / O switcher, an

automatic FM detector circuit, an FM bandpass filter, and a regulator circuit.

1) Operates off dual ± power supply which allows a

large reduction in the number of coupling capacitors

required. A built-in regulator makes it easy to con-

struct a power supply system.

2) A two-line SSB (Synchronized Serial Bus) control

decoder circuit is provided, allowing the various IC

modes to be set using serial control.

3) A four line input switcher is included (tuner, BS, and

line 1 / 2). The output switcher can switch between

STEREO, LEFT, and RIGHT, and Hi-Fi, MIX, and

NORMAL, and a BS MONITOR function is also pro-

vided.

4) The PNR processor and FM modulator / demodula-

tor circuit have reversed characteristics at recording

and playback. In addition, the adjustment for carrier

frequency and FM deviation / playback level are

common.

5) The built-in bandpass filter excels at attenuation of

other channels, and can be directly coupled to the

playback amplifier. The FM recording output block

has a high-performance low-pass filter to produce

sine wave output.

6) Slope-control-type FM-switching-noise compensa-

tion circuit.

7) Envelope detector circuit and noise-detector-type

automatic FM detector circuit.

8) VCO that uses the color signal sub-carrier frequency

(NTSC: 3.59545MHz, PAL: 4.433619MHz) and

auto-adjusting BPF circuit ensure stable adjustment

with no fluctuation due to mounting stress or time.

•

Absolute maximum ratings (Ta = 25°)

Parameter

Applied voltage

Storage temperature

Tstg

18, 36pin ··························· 6.0

39pin ······························ – 6.0

5, 6, 32pin ························

···

6.5

Pins other than the above 6.0

– 55 ~ + 125

Symbol

Limits

Unit

Power dissipation

850

∗

Operating temperature

Topr

– 10 ~ + 70

∗

Reduced by 8.5mW for each increase in Ta of 1

C over 25

C when mounted on a 70mm

70mm, t = 1.6mm glass epoxy board.

•

Features

•

Applications

VCRs

Video ICs

BH7800K

•

Block diagram

INPUT

SWITCH

MIX

AMP

PNR

ENVE

LOPE

Hi-Fi

DET

MODEM

ALC

DATA

DECODER

MODEM

BPF

VCO BPF

AUTO

ADJUST

D.O

COM.

OUT

REG

TUNER

R IN

TUNER

TUNER M IN

HiFi ALC

SCL

SDA

GNDD

FSC IN

NR TC L

WTNG L

NR EMPH L

LINE2 R IN

MUTE CTRL

NORMAL OUT

LINE L OUT

LINE R OUT

MIX OUT

MIX ALC

NORMAL IN

NR TC R

WTNG R

NR EMPH R

DC FB R

FM REC OUT

AUDIO HEAD SW

PULSE IN

FM ALC

VCCM

VCO FO ADJ

BPF ADJ

GNDM

ENVE OUT / ADJ FLAG

/ Hi-Fi DET

FM PB IN

DC FB L

LINE2 L IN

VREFP

ERP

GND

LINE1 R IN

LINE1 L IN

ERM

BS R IN

BS L IN

LINE

AMP

LINE

OUTPUT

SWITCH

PNR

Video ICs

BH7800K

•

Pin descriptions

Pin No.

Pin name

Format

Voltage

Function

2, 1, 3

TUNER IN L, R, M

150k

Ω

0.0V

Tuner input (L, R, M)

Hi-Fi ALC

EF (NPN) ~ 200

Ω

0.0V

ALC time constant setting for Hi-Fi audio

SCL

B (PNP)

—

CLOCK input for SSB control

SDA

B (PNP)

—

DATA input for SSB bus control

GNDD

GND for serial control

FSC IN

200k

Ω

0.0V

9, 25

NR TC L, R

—

– 5.0V

input for VCO and BPF adjustment

12, 22

DC FB L, R

23k

Ω

0.0V

PNR operating reference potential point

GNDM

—

0.0V

GND for PNR, MODEM and BPF

BPF f

ADJ

EF (NPN) ~ 200

Ω

1.9V

Center frequency adjustment for FM BPF

VCO f

ADJ

EF (NPN)

2.5V

VCO control current setting

VCCM

—

5.0V

for MODEM and BPF

FM ALC

EF (NPN) ~ 2.5k

Ω

0.0V

FM ALC time constant setting

AHSWP IN

B (PNP)

—

Audio head switching pulse input

NORMAL IN

100k

Ω

0.0V

Normal input

MIX OUT

EF (NPN)

0.0V

Mixer amplifier output for RF converter

30, 29

LINE L, R OUT

330

Ω

0.0V

Line output

NORMAL OUT

EF (P-P)

0.0V

Normal output

MUTE CTRL

Ω

( > 2.5V)

—

Line output mute control input

34, 33

LINE2 L, R IN

150k

Ω

0.0V

Line2 input (L, R)

—

5.0V

regulator

ERP

C (NPN)

5.0V

regulator error output

GND

—

0.0V

I / O switch GND

—

– 5.0V

regulator

41, 40

LINE1 IN L, R

150k

Ω

0.0V

LINE1 input (L, R)

ERM

C (PNP)

– 5.0V

regulator error output

44, 43

BS IN L, R

150k

Ω

0.0V

BS input (L, R)

PNR attack and recovery time setting

Attack R: 530

Ω

, Recovery R: 6.5k

Ω

10, 24

WTNG L, R

0.0V

Waiting characteristic, treble time constant (external C = 0.0047

11, 23

NR EMPH L, R

0.0V

NR emphasis time constant setting

(External C = 0.0047

FM PB IN

100k

Ω

0.0V

Playback FM input 1320mV

P-P

Typ.

Input coupling capacitor (GND ~ V

)

FM REC OUT

EF (NPN) ~ 200

Ω

3.3V

EE: recording FM output , sine wave output

PB: FM BPF output monitor

MIX ALC

EF (NPN) ~ 500

Ω

– 5.0V

ALC time constant setting for mixer amplifier

Attack and recovery time setting

VREFP

10k

Ω

2.5V

/ 2 reference voltage (power on detect and pre-charge functions)

/ ADJ FLAG

/ Hi-Fi DET

ENVE OUT

EE: 50k

Ω

EE: 0.8V

PB, ADJ: EF (NPN)

PB: 1.0V

FM Lch signal component envelope output

/ Hi-Fi DET output / ADJ FLAG output for ADJ

Note: EF: emitter follower, P-P: push pull, B: base, and C: collector.

All numerical values are standardized values.

Video ICs

BH7800K

•

Electrical characteristics (unless otherwise noted, Ta = 25°, UNREG – Vcc = + 10V, UNREG – V

= – 10V)

• Output switch control (W1bit5, W1bit4, W1bit3)

: STEREO

• BS L2 Through / LINE MUTE control (W1bit2, W1bit1)

: BSL2 Through / LINE MUTE OFF

• LINE AMP gain control (W1bit7, W1bit6)

: Typ. (+ 9.8dB)

• FM output cotrol (W5bit5)

: FM OUTPUT ON

• FM OUT switch control (W2bit4, W2bit3, W2bit2)

: FM REC output, MIX ratio 1 (-12.5dB)

• NTSC / PAL control (W2bit0)

: NTSC

• Recording MUTE (W2bit1)

: Recording MUTE

• Hi-Fi MUTE (W1bit0)

: OFF

• Normal input switch control (W3bit4, W3bit3)

: Hi-Fi MIX

• Hi-Fi ALC control (W3bit0)

: OFF

• ENVELOPE GAIN (Typ. / + 4dB / + 6dB) control (W4bit4, W4bit3) )

: Typ.

• FM detector level control (W4bit7, W4bit6)

: Typ.

• ENVE characteristic control (W4bit5)

: FNORM detect, no ENVE output

• DAC TEST control (W4bit2)

: OFF

• MUTE control (pin 32)

: L (MUTE)

Signal frequency f = 1kHz

• INPUT condition 1: TU / BS / LINE1 / LINE2 V

= – 20dBV

• INPUT condition 2: TU / BS / LINE1 / LINE2 V

= – 9.8dBV

• INPUT condition 3: TU / BS / LINE1 / LINE2 V

= – 5.0dBV

MODEM carrier frequency NTSC

Lch

1.30MHz

MODEM carrier frequency NTSC

Rch

1.70MHz

MODEM carrier frequency PAL

Lch

1.40MHz

MODEM carrier frequency PAL

Rch

1.80MHz

fsc NTSC

3.579545MHz

fsc PAL

4.433619MHz

Video ICs

BH7800K

Parameter

[REGULATOR]

∗

1: B.W. = 0.4 to 30kHz

∗

2: DIN AUDIO

Symbol

Min.

Typ.

Max.

Unit

Conditions

Quiesent current (positive supply) EE

qP EE

30.0

40.0

53.0

EE MODE, after carrier frequency

adjustment with no input

Quiesent current (positive supply) PB

qP PB

40.0

54.0

72.0

PB MODE, carrier frequency adjustment

FNORM, after BPF adjustment

Quiesent current (negative supply) EE

qM EE

– 20.0

– 15.0

– 11.0

EE MODE, after carrier frequency

adjustment with no input

PB MODE, carrier frequency adjustment

FNORM, after BPF adjustment

Quiesent current (negative supply) PB

qM PB

– 22.0

– 16.0

– 12.0

INPUT condition 2

ALC ON

ALC level

ALC

dBV

– 3.8

– 1.8

+ 0.2

INPUT condition 2,

∗

ALC ON

ALC distortion

THD

ALC

—

0.03

0.25

Relevant input: shorted to GND,

∗

Non-relevant input: Input condition 2,

∗

Crosstalk

dBV

—

– 88.0

– 75.0

INPUT condition 1

L & R input together,

∗

Normal out output level

ONORM

dBV

– 21.5

– 20.0

– 18.5

INPUT condition 1

L & R input together

Output level

OMIX

dBV

– 7.2

– 6.0

– 4.8

INPUT condition 1

L & R input together,

∗

Distortion

THD

MIX

—

0.08

0.50

INPUT condition 2

L & R input together

MIX ALC level

ALCMIX

dBV

– 4.2

– 2.7

– 1.2

= – 20.0dBV

Output level

OBS

OL2

dBV

– 11.4

– 10.2

– 9.0

= – 20.0dBV,

∗

Distortion

THD

—

0.005

0.08

BS IN pin shorted to GND,

∗

Output residual noise

ONBS

ONL2

dBV

—

– 99.0

– 86.0

[EE THROUGH] (INPUT: TU IN L / R, LINE1 IN L / R, LINE2 IN L / R, BS IN L / R OUTPUT: LINE OUT L / R)

[BS / L2 THROUGH] (INPUT: BS / LINE2 L / R IN OUTPUT: LINE OUT L / R)

[LINE AMP] (INPUT: NORMAL IN OUTPUT: LINE OUT L / R)

[MIX AMP] (INPUT: TU IN L / R, LINE1 IN L / R, LINE2 IN L / R, BS IN L / R OUTPUT: MIX OUT)

Regulator input voltage (positive)

4.75

5.10

5.45

Regulator input voltage (negative)

– 5.35

– 5.00

– 4.65

Line output level

OEE

dBV

– 11.4

– 10.2

– 9.0

INPUT condition 1

Channel balance (L / R)

– 0.8

0.0

0.8

INPUT condition 1

Distortion

THD

—

0.017

0.10

INPUT condition 1,

∗

Maximum output level

OMEE

dBV

9.0

10.7

—

THD = 1%,

∗

Output residual noise

ONEE

dBV

—

– 94.0

– 86.0

Relevant input shorted to GND,

∗

Muting level

dBV

—

– 103

– 90

INPUT condition 2,

∗

Line amplifier gain1

OLINE1

+ 9.0

+ 9.8

+ 10.6

= – 20dBV

(INPUT: TU L / R / M IN, BS L / R IN, LINE1 L / R IN, LINE2 L / R IN OUTPUT: NORMAL OUT)

Video ICs

BH7800K

Parameter

∗

1: B.W. = 0.4 to 30kHz

∗

2: DIN AUDIO

Symbol

Min.

Typ.

Max.

Unit

Conditions

FM MIX ratio (FM MIX1 mode)

– 14.3

– 12.5

– 10.7

Spectrum ratio 1.30MHz / 1.70MHz

[MODEM REC MODE] (INPUT: TUNER IN L / R, LINE1 IN L / R, LINE2 IN L / R, BS IN L / R OUTPUT: FM REC OUT)

[MODEM PB MODE]

(After BPF f

adjustment, V

= 1320mV

P-P

, 1.30MHz, 1.70MHz MIX IN)

(INPUT: FM PB IN, OUTPUT: LINE OUT L / R)

[Recording

→

playback overall characteristics]

(PB···INPUT: FM PB IN, OUTPUT: LINE OUT L / R)

(EE···INPUT: LINE IN L / R, OUTPUT: LINE OUT L / R)

Carrier frequency, after adjusting BPF

PB mode: FM PB IN = 1320mV

P-P

EE mode: INPUT condition 1

f = 1.30MHz, 1.70MHz 1: 1 MIX,

The difference between the EE and PB line out

levels when input is DEV = DEV

L,R

(the frequency deviation given above)

No input, after automatic adjustment

NTSC carrier frequency

Lch

Rch

NOL

MHz

1.2925

1.2975

1.3025

NOR

MHz

1.6940

1.6990

1.7040

No input, after automatic adjustment

PAL carrier frequency

Lch

Rch

POL

MHz

1.3930

1.3980

1.4030

POR

MHz

1.7945

1.7995

1.8045

INPUT condition 1

Frequency deviation

Lch

Rch

DEV

kHz

44.0

50.0

56.0

DEV

kHz

44.0

50.0

56.0

INPUT condition 3 (f = 10kHz)

Maximum frequency deviation

Lch

Rch

DEVMax.

kHz

118

140

162

DEVMax.

kHz

118

140

162

FM OUT SW: FM L mode

FM OUT SW: FM R mode

FM output level

Lch

Rch

OFML

P-P

310

355

410

OFMR

P-P

320

365

420

DEV

50.0kHz, f = 1kHz

DEV

50.0kHz, f = 1kHz

Demodulation output level 1

Demodulation output level 2

Lch

Rch

ODL

dBV

– 12.4

– 10.2

– 8.0

ODR

dBV

DEV

50.0kHz, f = 10kHz

Lch

ODL2

dBV

DEV

50.0kHz, f = 10kHz

Rch

ODR2

dBV

– 12.4

– 10.2

– 8.0

DEV

50.0kHz, f = 1kHz,

∗

DEV

50.0kHz, f = 1kHz,

∗

Demodulation distortion

Lch

Rch

THD

—

0.12

0.35

THD

—

0.13

0.35

Unmodulated

∗

Demodulation noise level

Line output recording / playback

level difference

Lch

Rch

Lch

ONDL

dBV

—

– 98.0

– 85.0

ONDR

dBV

—

– 98.0

– 85.0

RPL

– 1.2

0.0

+ 1.2

Rch

RPR

– 1.2

0.0

+ 1.2

Spectrum ratio of 2nd harmonic with respect to

fundamental

Lch: FM L mode, Rch: FM R mode

Spectrum ratio of 3rd harmonic with respect to

fundamental

Lch: FM L mode, Rch: FM R mode

Carrier 2nd harmonic

Lch

Rch

—

– 53.0

– 40.0

—

– 48.0

– 40.0

Carrier 3rd harmonic

Lch

Rch

—

– 52.0

– 40.0

—

– 55.0

– 42.0

ODL

– 10.0

ODL

– 7.8

ODL

– 5.6

ODR

– 10.0

ODR

– 7.8

ODR

– 5.6

BPF L / R level difference NTSC

∆

BPFN

– 5.0

0.0

5.0

After automatic adjustment, NTSC

f = 1.505MHz, V

= 400mV

P-P

BPF L / R level difference PAL

∆

BPFP

– 5.0

0.0

5.0

After automatic adjustment, PAL

f = 1.605MHz, V

= 400mV

P-P