ROHM BA3836

Multimedia ICs
Vocal fader IC
BA3836
Realizes karaoke functionality by enabling you to erase only the vocals from commercially available music software.
Applications
•Mini-components,
radio cassette players, car stereos,
karaoke sets
•1)Features
Vocal fader functions (erase vocals from commer-
4)
5)
6)
7)
cially available music software) all on one chip.
2) Has internal secondary active LPF to enable a highdegree of vocal cancellation (synchronous rejection
ratio) while retaining the same feeling.
3) Three control pins for switching between 4 modes:
through, vocal fader, sound multiplexing, and mute.
Key controller input and internal switches.
Internal microphone amplifier.
Low noise and low distortion.
Few external components.
•Absolute maximum ratings (Ta = 25°C)
Parameter
Symbol
Limits
Unit
Power supply voltage
VCC Max.
18
V
Power dissipation
1000∗1
Pd
mW
Operating temperature
Topr
– 40 ~ + 85
°C
Storage temperature
Tstg
– 55 ~ + 125
°C
∗1 Reduced by 10mW for each increase in Ta of 1°C over 25°C when mounted.
•Recommended operating conditions (Ta = 25°C)
Parameter
Power supply voltage
Symbol
Min.
Typ.
Max.
Unit
VCC
5.4
—
10
V
1
Multimedia ICs
BA3836
•Block diagram
C
B
A
ROUT
LP
LP
LP
RIN
16
15
14
13
12
11
10
9
–
LOGIC
– +
–
+
+
SW3
R
L+R
SW2
+
–
+
SW1
L–R
– +
L
+ –
SW4
+ –
1
2
3
4
5
6
7
8
VCC
MIC
LOUT
FK
TK
LIN
BIAS
GND
•Electrical characteristics (unless otherwise noted, Ta = 25°C, V
CC
Parameter
Symbol
Min.
Typ.
Max.
= 10V, fIN = 1kHz, VIN = 150mV, RL = 100kΩ)
Unit
Conditions
IQ
1.6
2.6
3.3
mA
Maximum output voltage
Vom
2.3
2.8
—
Vrms
L / R gain
GVT
10
14
17
dB
Through mode
Low frequency gain
GVF
10
14
17
dB
fIN = 50Hz, vocal fader mode
Microphone gain
GVM
5
8
11
dB
Quiescent current
Through mode
THD = 1%, through mode
—
Crosstalk
CT
54
70
—
dB
fIN = 1kHz
Mute attenuation
MU
74
80
—
dB
fIN = 1kHz
Vocal suppression rate
SV
27
33
—
dB
Vocal fader mode
Total harmonic distortion
THD
—
0.02
0.07
%
Through mode, BW: 400Hz to 30kHz
Noise level
VN
—
15
22
Vrms
Rg = 0, DIN AUDIO
Input impedance
RIN
35
50
65
kΩ
LIN, RIN, MICIN, FK
Control pin threshold
(high)
VthH
4.7
—
—
V
—
Control pin threshold
(low)
VthL
—
—
0.3
V
—
∆DCB
—
6
18
mV
Pin 15 switching
∆DCC
—
6
18
mV
Pin 16 switching
Output switching
DC differential
2
Multimedia ICs
BA3836
•Measurement circuit
A
4.7V
A
51k
1µ
A
1µ
51k
1µ
51k
C7
0.3V
0.047µ
0.22µ
C5
C6
10µ
16
15
14
13
12
11
10
9
C
B
A
Rout
LP
LP
LP
RIN
Vcc
MIC IN
LOUT
FK
TK
LIN
BIAS
GND
1
2
3
4
5
6
7
8
C1
A
C2
1µ
C4
C3
10µ
10µ
22µ
V
10µ
1k
100k
MEASUREMENT
FK
V
V
R
MIC
AUDIO
ANALYZER
L
600Ω
51k
OSC
Fig.1
3
Multimedia ICs
BA3836
Circuit operation
•Mode
table (A: pin 14, B: pin 15, C: pin 16)
A
B
C
LOUT
ROUT
TK
0
0
0
MUTE
MUTE
MUTE
0
0
1
VF
VF
VF
0
1
0
L
L
L
Sound multiplexing
0
1
1
L
R
L
Through
1
0
0
KC
KC
R
Sound multiplexing
1
0
1
KC
KC
VF
Vocal fader
1
1
0
KC
KC
L
1
1
1
KC
KC
L+R
MODE
Mute
Vocal fader
Sound multiplexing
L+R
0: 0V
1: 5V
VF: Vocal fader output
KC: Signal passed through key controller
(1) Microphone output is not muted during muting (ABC = 000 or 100).
(2) For the gain and relative phase, see block diagram.
1) L / R input and output in the through mode are synchronous with a gain of 14dB.
2) L / R input and TK output in the key controller mode are synchronous with a gain of 8dB.
3) L / R output and FK input in the key controller mode are synchronous with a gain of 6dB.
4) MIC input and L / R output are negative phase with a gain of 8dB.
4
Multimedia ICs
BA3836
•Application example
µ - COM
51k
1µ
51k
1µ
51k
1µ
10µ
0.047µ
0.22µ
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
TAPE,CD
LD,etc.
10µ
1k
1µ
POWER
AMP
Key-con
MICROPHONE
+
MICROPHONE
Fig.2
notes
•(1)Operation
•External dimensions (Units: mm)
We guarantee the application circuit design, but rec-
19.4 ± 0.3
9
1
8
6.5 ± 0.3
16
0.51Min.
3.2 ± 0.2 4.25 ± 0.3
ommend that you thoroughly check its characteristics in
actual use. If you change any of the external component values, check both the static and transient characteristics of the circuit, and allow sufficient margin in your
selections to take into account variations in the components and ICs.
(2) The vocal fader works by canceling out the synchronous component of the signal, leaving the low components in place. Consequently, the vocal fader may not
be very effective with certain recordings.
(3) In cases where output DC differential can cause
noise when switching between modes, use a time constant for the timing of control pin switching, or take
some other measure.
(4) Operating supply voltage may vary according to
ambient temperature. Using this IC outside the recommended supply voltage range may result in increased
crosstalk or mute attenuation.
7.62
0.3 ± 0.1
2.54
0.5 ± 0.1
0° ~ 15°
DIP16
5