ROHM BA7780KV Datasheet
1
Video ICs
Stereo zoom microphone amplifier
for camcorders
BA7780KV
The BA7780KV is a microphone amplifier developed for use in camcorders. The IC features an electronic volume circuit for presetting the curve required for the stereo zoom function, a microphone element power supply regulator, a
wind-noise rejection filter, a current limiting circuit for external accessory power supplies, and an input for external
microphone input. The IC operates off a 3.3V power supply.
•
Applications
Camcorders
•
Features
1) Operates off a 3.0V to 5.25V power supply.
2) Zoom microphone processing function on one chip.
3) Built-in electronic volume for external setting of sensitivity and control voltage.
4) Adjustable microphone element sensitivity.
5) Matrix amplifier for stereo emphasis.
6) Automatic switching circuit for external inputs, and
built-in external monaural decision circuit.
•
Absolute maximum ratings (Ta = 25°C)
•
Recommended operating conditions (Ta = 25°C)
Parameter
Symbol Limits Unit
V
CC
7.0 V
Pd 750
∗
mW
Topr
°C
Tstg °C
– 10 ~ + 70
– 55 ~ + 125
Power supply voltage
Power dissipation
Operating temperature
Storage temperature
∗
Reduced by 7.5mW for each increase in Ta of 1°C over 25°C.
Parameter Symbol Min. Typ. Max. Unit
V
CCS 3.0 — 5.25 V
Power supply voltage
2
Video ICs BA7780KV
•
Block diagram
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
MIX
REC
EXT
INT
13dB
GC
–
+
15dB
5dB
EXT
INT
BALANCE
RFLT
EXT
INT
13dB
RFLT
MIX
13dB
BALANCE
INT: 0N
GC
15dB
5dB
EXT
INT
BIAS
HPFC
CImt
13dB
OUT L
MIC MONO
Z B
Z A
Z SENSE
Z POINT
GAIN CONT
EX V
CC OUT
EX V
CC
VCC
Z AC
Z BC
IN MONI
HPF CONT
BIAS SUB
OUT R
BG
SUB IN L
INT IN L
VREG L
EXT IN L
MODE 43
PRE OUT L
OUT AMP IN L
INV OUT L
GC OUT L
MTX IN L
MTX OUT L
BL OUT L
HPF IN L
BIAS L
EXTC L
RIPL
SUB IN R
INT IN R
VREG R
EXT IN R
MODE 6
PRE OUT R
OUT AMP IN R
INV OUT R
GC OUT R
MTX IN R
MTX OUT R
BL OUT R
HPF IN R
BIAS R
EXTC R
GND L
MIX1 IN L
GZ CONT
SUB INV2 OUT
SUB INV2 IN
SUB BUF2 OUT
SUB VCA OUT
SUB VCA IN
MIX2 OUT
SUB BUF2 IN
SUB INV1 OUT
SUB BUF1 OUT
SUB BUF1 IN
MIX1 OUT
MIX1 IN R
GND R
INT: ON
REG
–
+
+–
3
Video ICs BA7780KV
•
Pin descriptions
1 RIPL 1.65 50kΩ
2 1.65 100kΩ
3 1.65 75kΩ
4 2.5 C
5 1.65 75kΩ
6 — 25kΩ
7 1.65 EF (P - P)
8 1.65 100kΩ
9 1.65 EF (P - P)
10 1.65 EF (P - P)
11 1.65 B
12 1.65 EF (P - P)
13 1.65 EF (P - P)
14 1.65 100kΩ
15 1.65 EF (P - P)
16 2.3 C
17 1.65 C (P - P)
18 1.65 EF (P - P)
19 — 10kΩ
20 —C
21 —B
22 —B
23 VCC 3.3 —
24 4.75 —
25 4.5 C
26 — 50kΩ
27 —B
28 —B
29 —B
30 —B
31 —C
32 1.65 EF (P - P)
33 2.3 C
34 1.65 EF (P - P)
35 1.65 100kΩ
36 1.65 EF (P - P)
37 1.65 EF (P - P)
38 1.65 B
39 1.65 EF (P - P)
40 1.65 EF (P - P)
41 1.65 100kΩ
42 1.65 EF (P - P)
SUB IN R
INT IN R
VREG R
EXT IN R
MODE 6
OUT AMP IN R
PRE OUT R
INV OUT R
GC OUT R
MTX IN R
MTX OUT R
BL OUT R
HPF IN R
BIAS R
EXTC R
OUT R
BIAS SUB
HPF CONT
IN MONI
Z BC
Z AC
EX V
CC
EX VCC OUT
GAIN CONT
Z POINT
Z SENSE
Z A
Z B
MIC MONO
OUT L
EXTC L
BIAS L
HPF IN L
BL OUT L
MTX OUT L
MTX IN L
GC OUT L
INV OUT L
OUT AMP IN L
PRE OUT L
Pin No.
For bias ripple filter capacitor
Sub microphone input
Internal microphone input
Regulator output
External microphone input
Mode control 6 input
Preamplifier output
Out amplifier input
Inverter output
Gain control amplifier output
Matrix amplifier input
Matrix amplifier output
Zoom balance circuit output
HPF input
Bias output
For connection of out amplifier output inhibit capacitor
Signal output
Sub bias output
HFP control input
Input switch decision signal output
For connection of noise cutting capacitor for zoom control signal
For connection of noise cutting capacitor for zoom control signal
V
CC
Current limiter VCC
Current limiter output
Gain control amplifier switch input
Cross-point variation input for zoom balance circuit
Sensitivity variation input for zoom balance circuit
Zoom control input
Zoom control input
External microphone monaural decision signal output
Signal output
For connection of out amplifier output inhibit capacitor
Bias output
HPF input
Zoom balance circuit output
Matrix amplifier output
Matrix amplifier input
Gain control amplifier output
Inverter output
Out amplifier input
Preamplifier output
Pin voltage (V)
FormatFunction
Pin name
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