ROHM BH7800K

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.
Applications
•VCRs
•1)Features
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 construct 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 provided.
4) The PNR processor and FM modulator / demodulator 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 compensation circuit.
7) Envelope detector circuit and noise-detector-type
automatic FM detector circuit.
8) VCO that uses the color signal sub-carrier frequency
fSC (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
Symbol
Limits
Unit
VCC
18, 36pin ··························· 6.0
V
VEE
39pin ······························ – 6.0
V
VIN
5, 6, 32pin ························ 6.5
V
VIN
Pins other than the above ··· 6.0
V
Pd
850∗
mW
Operating temperature
Topr
– 10 ~ + 70
°C
Storage temperature
Tstg
– 55 ~ + 125
°C
Power dissipation
∗ 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.
1
Video ICs
BH7800K
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
•Block diagram
33
32
31
30
29
28
27
26
25
24
23
MIX
AMP
LINE2 L IN 34
22 DC FB R
PNR
21 FM REC OUT
VREFP 35
FM
OUT
SW
MODEM
VCC 36
ERP 37
20
AUDIO HEAD SW
PULSE IN
AMP
LINE
19 FM ALC
LINE
AMP
D.O
COM.
GND 38
18 VCCM
REG
VEE 39
LINE1 R IN 40
17 VCO FO ADJ
VCO BPF
AUTO
ADJUST
OUTPUT
SWITCH
FM
BPF
16 BPF ADJ
LINE1 L IN 41
15 GNDM
ERM 42
ALC
ENVE
LOPE
MODEM
INPUT
BS R IN 43
ENVE OUT / ADJ FLAG
/ Hi-Fi DET
13 FM PB IN
SWITCH
DATA
DECODER
PNR
1
2
3
4
5
6
7
8
9
10
11
TUNER L IN
TUNER M IN
HiFi ALC
SCL
SDA
GNDD
FSC IN
NR TC L
WTNG L
NR EMPH L
12 DC FB L
TUNER R IN
BS L IN 44
2
14
Hi-Fi
DET
Video ICs
BH7800K
•Pin descriptions
Pin No.
Pin name
2, 1, 3
TUNER IN L, R, M
Tuner input (L, R, M)
Function
Voltage
0.0V
Format
150kΩ
4
Hi-Fi ALC
ALC time constant setting for Hi-Fi audio
0.0V
EF (NPN) ~ 200Ω
5
SCL
CLOCK input for SSB control
—
B (PNP)
6
SDA
DATA input for SSB bus control
—
B (PNP)
7
GNDD
GND for serial control
—
—
8
FSC IN
fSC input for VCO and BPF adjustment
0.0V
200kΩ
9, 25
NR TC L, R
PNR attack and recovery time setting
Attack R: 530Ω, Recovery R: 6.5kΩ
– 5.0V
—
10, 24
WTNG L, R
Waiting characteristic, treble time constant (external C = 0.0047µF)
0.0V
—
11, 23
NR EMPH L, R
NR emphasis time constant setting
(External C = 0.0047µF)
0.0V
—
12, 22
DC FB L, R
PNR operating reference potential point
0.0V
23kΩ
13
FM PB IN
Playback FM input 1320mVP-P Typ.
Input coupling capacitor (GND ~ VCC)
0.0V
100kΩ
14
ENVE OUT
/ ADJ FLAG
/ Hi-Fi DET
FM Lch signal component envelope output
/ Hi-Fi DET output / ADJ FLAG output for ADJ
EE: 0.8V
PB: 1.0V
EE: 50kΩ
PB, ADJ: EF (NPN)
15
GNDM
GND for PNR, MODEM and BPF
0.0V
—
16
BPF f0 ADJ
Center frequency adjustment for FM BPF
1.9V
EF (NPN) ~ 200Ω
17
VCO f0 ADJ
VCO control current setting
2.5V
EF (NPN)
18
VCCM
VCC for MODEM and BPF
5.0V
—
19
FM ALC
FM ALC time constant setting
0.0V
EF (NPN) ~ 2.5kΩ
20
AHSWP IN
Audio head switching pulse input
—
B (PNP)
21
FM REC OUT
EE: recording FM output , sine wave output
PB: FM BPF output monitor
3.3V
EF (NPN) ~ 200Ω
26
NORMAL IN
Normal input
0.0V
100kΩ
MIX ALC
ALC time constant setting for mixer amplifier
Attack and recovery time setting
27
28
– 5.0V
EF (NPN) ~ 500Ω
MIX OUT
Mixer amplifier output for RF converter
0.0V
30, 29
LINE L, R OUT
Line output
0.0V
330Ω
31
NORMAL OUT
Normal output
0.0V
EF (P-P)
32
EF (NPN)
MUTE CTRL
Line output mute control input
—
3kΩ ( > 2.5V)
LINE2 L, R IN
Line2 input (L, R)
0.0V
150kΩ
35
VREFP
VCC / 2 reference voltage (power on detect and pre-charge functions)
2.5V
10kΩ
36
VCC
VCC regulator
5.0V
—
37
ERP
VCC regulator error output
5.0V
C (NPN)
38
GND
I / O switch GND
39
VEE
VEE regulator
34, 33
41, 40
42
44, 43
LINE1 IN L, R
LINE1 input (L, R)
ERM
VEE regulator error output
BS IN L, R
BS input (L, R)
0.0V
—
– 5.0V
—
0.0V
– 5.0V
0.0V
150kΩ
C (PNP)
150kΩ
Note: EF: emitter follower, P-P: push pull, B: base, and C: collector.
All numerical values are standardized values.
3
Video ICs
BH7800K
•Input / output circuits
TUNER L / R / M IN (2, 1, 3pin) BS L / R IN (44, 43pin) LINE1 L / R IN (41, 40pin) LINE2 L / R IN (34, 33pin)
VCC
– 2.0V
(2, 3, 33, 34, 40,
41, 43, 44pin)
3k
1
2.0V
150k
VEE
GND
LINE L / R OUT (30, 29pin)
MIX OUT (28pin)
VCC
VCC
200
50
28
25k
(29pin)
330
5k
200
30
26k
47k
11.56k
50
30k
VEE
VEE
GND
GND
FM REC OUT (21pin)
FM PB IN (13pin)
VCC
VCC
200
3.5V
200
25k
25k
20p
2k
21
13
PB
3p
4
8k
12.5k
100k
VEE
VEE
GND
GND
Video ICs
BH7800K
AHSWP IN (20pin)
ENVE OUT / ADJ FLAG / Hi-Fi DET (14pin)
VCC
VCC
PB
200
42.5k
30k
5k
14
20
50k
VEE
VEE
GND
GND
SCL (5pin) SDA (6pin)
FSC IN (8pin)
VCC
VCC
2k
8
30k
5
(6pin)
100k
3V
50k
100k
VEE
VEE
GND
MUTE CTRL (32pin)
32
VCC
2.5V
51k
10k
2k
200
16k
50k
10k
VEE
GND
5
Video ICs
BH7800K
•Electrical characteristics (unless otherwise noted, Ta = 25°, UNREG – Vcc = + 10V, UNREG – V
• Output switch control (W1bit5, W1bit4, W1bit3)
• BS L2 Through / LINE MUTE control (W1bit2, W1bit1)
• LINE AMP gain control (W1bit7, W1bit6)
• FM output cotrol (W5bit5)
• FM OUT switch control (W2bit4, W2bit3, W2bit2)
• NTSC / PAL control (W2bit0)
• Recording MUTE (W2bit1)
• Hi-Fi MUTE (W1bit0)
• Normal input switch control (W3bit4, W3bit3)
• Hi-Fi ALC control (W3bit0)
• ENVELOPE GAIN (Typ. / + 4dB / + 6dB) control (W4bit4, W4bit3) )
• FM detector level control (W4bit7, W4bit6)
• ENVE characteristic control (W4bit5)
• DAC TEST control (W4bit2)
• MUTE control (pin 32)
Signal frequency f = 1kHz
• INPUT condition 1: TU / BS / LINE1 / LINE2 VIN = – 20dBV
• INPUT condition 2: TU / BS / LINE1 / LINE2 VIN = – 9.8dBV
• INPUT condition 3: TU / BS / LINE1 / LINE2 VIN = – 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
6
EE
= – 10V)
: STEREO
: BSL2 Through / LINE MUTE OFF
: Typ. (+ 9.8dB)
: FM OUTPUT ON
: FM REC output, MIX ratio 1 (-12.5dB)
: NTSC
: Recording MUTE
: OFF
: Hi-Fi MIX
: OFF
: Typ.
: Typ.
: FNORM detect, no ENVE output
: OFF
: L (MUTE)
Video ICs
BH7800K
Parameter
Symbol
Min.
Typ.
Max.
Unit
Conditions
[REGULATOR]
Quiesent current (positive supply) EE
IqP
EE
30.0
40.0
53.0
mA
EE MODE, after carrier frequency
adjustment with no input
Quiesent current (positive supply) PB
IqP
PB
40.0
54.0
72.0
mA
PB MODE, carrier frequency adjustment
FNORM, after BPF adjustment
Quiesent current (negative supply) EE
IqM
EE
– 20.0
– 15.0
– 11.0
mA
EE MODE, after carrier frequency
adjustment with no input
Quiesent current (negative supply) PB
IqM
PB
– 22.0
– 16.0
– 12.0
mA
PB MODE, carrier frequency adjustment
FNORM, after BPF adjustment
Regulator input voltage (positive)
VCC
4.75
5.10
5.45
Regulator input voltage (negative)
VEE
– 5.35
– 5.00
– 4.65
V
V
[EE THROUGH] (INPUT: TU IN L / R, LINE1 IN L / R, LINE2 IN L / R, BS IN L / R
OUTPUT: LINE OUT L / R)
Line output level
VOEE
– 11.4
Channel balance (L / R)
CBEE
– 0.8
– 10.2
dBV
INPUT condition 1
0.0
– 9.0
0.8
dB
INPUT condition 1
INPUT condition 1,∗1
Distortion
THDEE
—
0.017
0.10
%
Maximum output level
VOMEE
9.0
10.7
—
dBV
THD = 1%,∗1
– 3.8
– 1.8
+ 0.2
dBV
INPUT condition 2
ALC ON
THDALC
—
0.03
0.25
Output residual noise
VONEE
—
– 94.0
– 86.0
dBV
Relevant input shorted to GND,∗2
Crosstalk
CTEE
—
– 88.0
– 75.0
dBV
Relevant input: shorted to GND,∗2
Non-relevant input: Input condition 2,∗2
Muting level
MTEE
—
– 103
– 90
dBV
INPUT condition 2,∗2
ALC level
VALC
ALC distortion
%
(INPUT: TU L / R / M IN, BS L / R IN, LINE1 L / R IN, LINE2 L / R IN
Normal out output level
VONORM
[BS / L2 THROUGH] (INPUT: BS / LINE2 L / R IN
VOBS
VOL2
Output level
– 21.5
THDBS
THDL2
—
Output residual noise
VONBS
VONL2
—
Line amplifier gain1
– 18.5
– 10.2
– 9.0
0.005
0.08
– 99.0
VOMIX
dBV
VIN = – 20.0dBV
%
dBV
+ 9.0
+ 9.8
+ 10.6
dB
– 7.2
– 6.0
– 4.8
Distortion
THDMIX
—
0.08
0.50
MIX ALC level
VALCMIX
– 4.2
– 2.7
– 1.2
∗2: DIN
INPUT condition 1
L & R input together,∗1
– 86.0
[MIX AMP] (INPUT: TU IN L / R, LINE1 IN L / R, LINE2 IN L / R, BS IN L / R
∗1: B.W. = 0.4 to 30kHz
dBV
VIN = – 20.0dBV,∗1
BS IN pin shorted to GND,∗2
OUTPUT: LINE OUT L / R)
VOLINE1
Output level
OUTPUT: NORMAL OUT)
OUTPUT: LINE OUT L / R)
– 11.4
Distortion
[LINE AMP] (INPUT: NORMAL IN
– 20.0
INPUT condition 2,∗1
ALC ON
VIN = – 20dBV
OUTPUT: MIX OUT)
dBV
%
dBV
INPUT condition 1
L & R input together
INPUT condition 1
L & R input together,∗1
INPUT condition 2
L & R input together
AUDIO
7
Video ICs
BH7800K
Parameter
Symbol
Min.
Typ.
Max.
Unit
Conditions
[MODEM REC MODE] (INPUT: TUNER IN L / R, LINE1 IN L / R, LINE2 IN L / R, BS IN L / R
NTSC carrier frequency
PAL carrier frequency
Frequency deviation
Maximum frequency deviation
FM output level
Carrier 2nd harmonic
Carrier 3rd harmonic
OUTPUT: FM REC OUT)
Lch
fNOL
1.2925
1.2975
1.3025
MHz
Rch
fNOR
1.6940
1.6990
1.7040
MHz
Lch
fPOL
1.3930
1.3980
1.4030
MHz
Rch
fPOR
1.7945
1.7995
1.8045
MHz
Lch
DEVL
44.0
50.0
56.0
± kHz
Rch
DEVR
44.0
50.0
56.0
± kHz
Lch
DEVMax.L
118
140
162
± kHz
Rch
DEVMax.R
118
140
162
± kHz
Lch
VOFML
310
355
410
mVP-P
FM OUT SW: FM L mode
Rch
VOFMR
320
365
420
mVP-P
Lch
f2L
—
– 53.0
– 40.0
dB
Rch
f2R
—
– 48.0
– 40.0
dB
Lch
f3L
—
– 52.0
– 40.0
dB
Rch
f3R
—
– 55.0
– 42.0
dB
FM OUT SW: FM R mode
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
– 12.5
– 10.7
dB
Spectrum ratio 1.30MHz / 1.70MHz
FM MIX ratio (FM MIX1 mode)
fLR
– 14.3
No input, after automatic adjustment
No input, after automatic adjustment
INPUT condition 1
INPUT condition 3 (f = 10kHz)
[MODEM PB MODE] (INPUT: FM PB IN, OUTPUT: LINE OUT L / R)
(After BPF f0 adjustment, VIN = 1320mVP-P, 1.30MHz, 1.70MHz MIX IN)
Demodulation output level 1
Lch
VODL
– 12.4
– 10.2
– 8.0
dBV
DEVL = ± 50.0kHz, f = 1kHz
Rch
VODR
– 12.4
– 10.2
– 8.0
dBV
DEVR = ± 50.0kHz, f = 1kHz
Lch
VODL2
VODL
– 10.0
VODL
– 7.8
VODL
– 5.6
dBV
DEVL = ± 50.0kHz, f = 10kHz
VODR2
VODR
– 10.0
VODR
– 7.8
VODR
– 5.6
dBV
DEVR = ± 50.0kHz, f = 10kHz
Demodulation output level 2
Rch
Demodulation distortion
Demodulation noise level
Lch
THDDL
—
0.12
0.35
%
DEVL = ± 50.0kHz, f = 1kHz,∗1
Rch
THDDR
—
0.13
0.35
%
DEVR = ± 50.0kHz, f = 1kHz,∗1
Lch
VONDL
—
– 98.0
– 85.0
dBV
Rch
VONDR
—
– 98.0
– 85.0
dBV
Unmodulated
∗2
[Recording→playback overall characteristics] (EE···INPUT: LINE IN L / R, OUTPUT: LINE OUT L / R)
(PB···INPUT: FM PB IN, OUTPUT: LINE OUT L / R)
Lch
VRPL
– 1.2
0.0
+ 1.2
dB
Line output recording / playback
level difference
Rch
VRPR
– 1.2
0.0
+ 1.2
dB
Carrier frequency, after adjusting BPF
EE mode: INPUT condition 1
PB mode: FM PB IN = 1320mVP-P
f = 1.30MHz, 1.70MHz 1: 1 MIX,
The difference between the EE and PB line out
levels when input is DEV = DEVL,R
(the frequency deviation given above)
[FM BPF] (INPUT: FM PB IN, OUTPUT: BPF MONITOR L / R)
BPF L / R level difference NTSC
∆VBPFN
– 5.0
0.0
5.0
dB
After automatic adjustment, NTSC
f = 1.505MHz, VIN = 400mVP-P
BPF L / R level difference PAL
∆VBPFP
– 5.0
0.0
5.0
dB
After automatic adjustment, PAL
f = 1.605MHz, VIN = 400mVP-P
∗1: B.W. = 0.4 to 30kHz
8
∗2: DIN
AUDIO
Video ICs
Parameter
BH7800K
Symbol
Min.
Typ.
Max.
Unit
Conditions
(LcH, RcH mix input signal level 1320mVP-P (RATIO 1: 1))
〈NTSC Lch〉
1.30MHz insertion loss
1.15MHz attenuation
1.45MHz attenuation
1.70MHz attenuation
– 14.1
dB
1.30MHz + 1.70MHz
FM ALC ON
A T T NLC
– 5.3
A T T NLC
– 2.3
dB
1.15MHz + 1.70MHz
A T T NLC
– 5.0
A T T NLC
– 2.5
dB
1.45MHz + 1.70MHz
—
A T T NLC
– 30.0
dB
1.30MHz + 1.70MHz
A T T NLC
– 20.1
– 17.1
A T T NL
A T T NLC
– 9.8
A T T NLC
– 8.1
1.15
A T T NL
1.45
A T T NL
1.70
—
〈NTSC Rch〉
1.70MHz insertion loss
1.55MHz attenuation
1.85MHz attenuation
1.30MHz attenuation
A T T NRC
– 21.3
– 18.3
– 15.3
dB
1.30MHz + 1.70MHz
FM ALC ON
A T T NR
A T T NRC
– 8.8
A T T NRC
– 5.7
A T T NRC
– 3.4
dB
1.55MHz + 1.30MHz
A T T NRC
– 9.5
A T T NRC
– 4.7
A T T NRC
– 1.4
dB
1.85MHz + 1.30MHz
—
—
A T T NRC
– 30.0
dB
1.30MHz + 1.70MHz
– 12.9
dB
1.40MHz + 1.80MHz
A T T PLC
– 30.0
dB
1.40MHz + 1.80MHz
– 14.3
dB
1.40MHz + 1.80MHz
A T T PRC
– 30.0
dB
1.40MHz + 1.80MHz
1.55
A T T NR
1.85
A T T NR
1.30
〈PAL Lch〉
1.40MHz insertion loss
1.80MHz attenuation
A T T PLC
A T T PL
1.80
– 18.9
—
– 15.9
—
PAL Rch
1.80MHz insertion loss
1.40MHz attenuation
A T T PRC
A T T PR
1.40
– 20.3
—
– 17.3
—
[FNORM→Hi-Fi recovery delay circuit]
Return delay time
τFNDLY
110
125
140
mS
Delay time from input of FM PB IN
(1.30MHz, 1.70MHz 1: 1 MIX)
1320mVP-P to rise of ENVE OUT
AUDIO HEAD PULSE IN
: f = 30Hz, 5VP-P, rectangular wave
(INPUT: FM PB IN, OUTPUT: ENVE OUT)
〈Envelope output circuit〉
0dB = 1320mVP-P, 1.30MHz & 1.70MHz MIX input
Envelope output level SP0
VENVSP0
—
0
100
mV
No signal, STANDARD MODE
Envelope output level SP1
VENVSP1
2.08
2.58
3.08
V
VIN = 0dB, STANDARD MODE
Envelope output level SP2
VENVSP2
3.70
3.95
4.20
V
VIN = + 10dB, STANDARD MODE
Envelope output level EP1
VENVEP1
1.96
2.46
2.96
V
VIN = – 4dB, + 4dB MODE
L mode holding voltage
VH5L
0.0
—
0.5
V
H mode holding voltage
VH5H
2.5
—
VCC
V
[Control system mode holding voltage]
〈CLOCK IN〉
9
Video ICs
BH7800K
Parameter
Symbol
Min.
Typ.
Max.
Unit
L mode holding voltage
VH6L
0.0
H mode holding voltage
VH6H
2.5
—
0.5
V
—
VCC
V
MUTE holding voltage
VH32L
0.0
DC MUTE holding voltage
VH32H
3.9
—
1.0
V
—
VCC
V
Conditions
〈DATA IN〉
〈MUTE CTRL〉
NORMAL IN
MIX OUT
LINE L OUT
LINE R OUT
1k
22k
22k
22k
MUTE CTRL
NORMAL OUT
•Measurement circuit
VEE
1k
0.022µ
0.0047µ
10µ
2.2M
47µ
1500p
1500p
VEE
LINE2 R IN
S33
33
32
31
30
29
28
27
26
25
24
23
P.OFF: H
LINE2 L IN
1k
S34
Tr.35
220µ
MIX
AMP
34
22
PNR
R35
0.01µ
35
21
4.7µ
100µ
4.7k
0.022µ
D.O
COM.
LINE
AMP
38
20
18
47µ
REG
27k
39
VEE
100µ
1k
17
VCO BPF
AUTO
ADJUST
OUTPUT
SWITCH
40
LINE1 R IN
27k
FMBPF
41
15
S41
4.7k
42
ALC
ENVE
LOPE
MODEM
43
BS R IN
13
DATA
DECODER
44
12
S44
1
2
3
4
5
6
7
8
9
1k
S2
1k
S3
TUNER L IN
Fig.1
FSC IN
DATA
CLOCK
VEE
TUNER M IN
10
10µ
S1
2.2M
1k
47µ
TUNER R IN
11
ENVELOPE
/ Hi-Fi DET
/ ADJ FLAG
FM PB IN
220µ
PNR
0.022µ
1k
47k
SWITCH
S43
BS L IN
14
Hi-Fi
DET
INPUT
0.0047µ
1k
UNREG VEE
10
16
S40
LINE1 L IN
1k
AHSWP IN
19
AMP
LINE
37
UNREG VCC
FM REC OUT
10k
MODEM
36
VCC
FM
OUT
SW
Video ICs
BH7800K
Circuit operation
•Function
table
The BH7800K includes the following functions on one chip.
No.
Block name
Main function
Pin numbers
Power supply
35 ~ 39, 42
UNREG—VCC: + 10V
UNREG—VEE: – 10V
GND: 38
1
Regulator
· ± 5V regulator (VCC, VEE)
· Anti-pop circuit (ANTI—POP)
2
SSB control
· SSB data decoder
5~7
VCC3 (internal power supply)
GND: 7
3
Input switcher
· TUNER (L, R, M) / LINE 1, 2 (L,R) / BS (L, R) switch
33, 34,
40, 41
43, 44
1~3
VCC (internally wired)
VEE (internally wired)
GND: 38
Output switcher
· Line amplifier: + 9.8dB, + 10.8dB, + 12.0dB, + 14.8dB
· STEREO / LEFT / RIGHT / NORMAL switch
· MIX ON / OFF switch
· Mute switch
· MIXER amplifier for RF converter (with ALC function)
· BS / LINE2 through mode
27 ~ 30
32
VCC (internally wired)
VEE (internally wired)
GND: 38
PNR processor
· 20kHz line low-pass filter (secondary LPF)
· 20kHz PNR low-pass filter (secondary LPF)
· PNR processor (MOA, CCA, WTNG, DET)
· Emphasis / de-emphasis (EMPH / DEEMPH)
· Switching noise slope-control type differential compensation circuit
9 ~ 12
22 ~ 25
VCC (internally wired)
VEE (internally wired)
GND: 38
Modulator
· FM modulation circuit (VCO, DEV)
· FM demodulation / FM BPF MONITOR output switch (FMOUT SW)
: FM MIX1 to 4, FM L, FM R, BPF L, BPF R
· Recording FM treble cutoff filter (FM LPF)
· Over modulation limiter (AUDIO LIM)
· Playback FM limiter (FM LIM)
· VCO, BPF automatic adjustment circuit (AUTO AUDIO ADJUST)
· NTSC / PAL switch function
· Auto adjustment complete FLAG output circuit (ADJ FLAG)
8, 14
17, 21
VCC: 18
VEE (internally wired)
GND: 15
8
FM detector control
· D.O.detector circuit (D.O. DET)
· Auto FM detector circuit (noise detect method) (FM DET)
: Typ. , + 30%, – 10%
· Envelope detector circuit (ENVE)
· Hold pulse generator
14, 20
VCC: 18
(internally wired)
GND: 15
9
FM BPF
· FM bandpass filter (FM BPF)
· NTSC / PAL switch function
· FM input automatic level adjust circuit (FM ALC: ON / OFF)
4
6
7
13, 16, 19
VCC: 18
GND: 15
11
Video ICs
BH7800K
NORMAL IN
22k
MIX OUT
LINE R OUT
LINE L OUT
NORMAL OUT
22k
MUTE CTRL
•Application example
1500p
33
32
31
30
29
28
27
0.022µ
10µ
47µ
LINE2 R IN
26
25
0.0047µ
VEE
2.2M
1500p
VEE
24
23
P.OFF: H
LINE2 L IN
Tr.35
220µ
MIX
AMP
34
R35
22
PNR
35
21
4.7µ
MODEM
36
VCC
FM
OUT
SW
100µ
38
20
AUDIO HEAD
SWITCH
PULSE IN
0.022µ
19
AMP
LINE
37
D.O
COM.
LINE
AMP
UNREG VCC
4.7k
FM REC OUT
18
47µ
REG
27k
39
VEE
100µ
SWITCH
27k
FMBPF
15
42
ALC
ENVE
LOPE
MODEM
INPUT
13
SWITCH
DATA
DECODER
1
2
3
4
5
6
7
8
9
2.2M
47µ
TUNER R IN
TUNER L IN
10
11
fsc IN
DATA
VEE
CLOCK
TUNER M IN
12
0.0047µ
44
FM PB IN
220µ
PNR
10µ
BS L IN
43
ENVELOPE
/ Hi-Fi DET
/ ADJ FLAG
14
Hi-Fi
DET
0.022µ
4.7k
BS R IN
16
41
LINE1 L IN
UNREG VEE
VCO BPF
AUTO
ADJUST
OUTPUT
40
LINE1 R IN
17
Fig.2
notes
•TheOperation
VCO oscillation frequency and frequency deviation, and the BPF center frequency are directly influenced by the
temperature characteristics of the setting resistors connected to pins 16 and 17. Use metal-film components.
12
Video ICs
BH7800K
•Electrical characteristic curves
– 10
– 10
– 20
– 20
1.4MHz
1.7MHz
GAIN: Gv (dB)
1.3MHz
GAIN: Gv (dB)
Rch
Lch
Rch
Lch
– 30
– 40
1.8MHz
– 30
– 40
– 50
– 50
0.75
1.50
2.25
0.85
1.60
2.35
FREQUENCY: f (MHz)
FREQUENCY: f (MHz)
Fig. 3 FM BPF frequency characteristics
(NTSC)
Fig. 4 FM BPF frequency characteristics
(PAL)
•External dimensions (Units: mm)
14.0 ± 0.3
10.0 ± 0.2
23
22
44
12
2.15 ± 0.1
0.05
1
0.8
11
0.35 ± 0.1
1.2
14.0 ± 0.3
10.0 ± 0.2
33
34
0.15 ± 0.1
0.15
QFP44
13