ROHM BA7726AS

Multimedia ICs
Analog compander with vocal fader
for KARAOKE
BA7726AS / BA7726AFS
The BA7726AS and BA7726AFS are analog companders for karaoke echo systems and have internal logarithmic
compression and expansion circuits, a stereo line mixer amplifier, vocal fader function, vocal detection function,
microphone ALC, microphone ON / OFF switch, and output switch. When used together with the BU9252 8-bit digital
delay, these ICs form a high-grade karaoke echo system with minimum components.
Applications
•Portable
CD stereos with karaoke functions, VCRs, mini component stereo systems, LD players
•1)Features
Internal stereo line mixer amplifier, allowing selec-
4) Internal microphone ON / OFF switch.
5) Vocal detection.
6) Internal microphone ALC function.
7) Internal anti-popping circuit.
tion of through output, left output, or right output.
2) Internal vocal elimination function, suitable for vocal
faders and left and right output.
3) Echo level and loop ratio are DC-adjustable with the
internal electronic volume control (EVR).
•Absolute maximum ratings (Ta = 25°C)
Parameter
Symbol
Limits
VCC
14
Power supply voltage
Power dissipation
BA7726AS
Pd
BA7726AFS
Unit
V
1250
∗1
mW
850∗2
Operating temperature
Topr
– 10 ~ + 70
°C
Storage temperature
Tstg
– 55 ~ + 125
°C
∗1 Reduced by 12.5mW for each increase in Ta of 1°C over 25°C.
∗2 Reduced by 8.5mW for each increase in Ta of 1°C over 25°C.
•Recommended operating conditions (Ta = 25°C)
Parameter
Power supply voltage
Symbol
Min.
Typ.
Max.
Unit
VCC
4.5
9.0
12.0
V
1
2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
LINE OUT R
LINE OUT L
L / VF / R CTRL
MUTE CTRL
LINE IN R
LINE IN L
VF LPF1
VF LPF2
VF LPF3
GND
ECHO LEVEL CTRL
LOOP GAIN CTRL
EXP DET
EXP DET CT
EXP BF IN
DLY BF OUT
+
VOCAL
DET
ALC
–
COMPRESS
VOCAL
FADER
SW
VR
+
L / ST / R CTRL
NO / VC CTRL
VO DET
VO DET LEVEL
ALC DET LEVEL
ALC DET
MIC AMP IN
MIC AMP NF
BIAS
VCC
CMP DET
CMP DET CT
CMP OUT
CMP BF NF IN
CMP BF OUT
DLY BF NF IN
Multimedia ICs
BA7726AS / BA7726AFS
•Block diagram
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
VR
OUTSW
–
VR
+ –
EXPAND
Multimedia ICs
BA7726AS / BA7726AFS
•Pin descriptions
Pin No.
Pin name
Function
Voltage
Pin type
EF (P - P)
2, 1
LINE OUT L / R
Line output (L, R)
4.5V
3
L / VF / R CTRL
Line output switching (LEFT / VOCAL FADER / RIGHT)
2.5V
4
MUTE CTRL
Line mute control input
—
∗
∗
6, 5
LINE IN L / R
Line input (L, R)
4.5V
100kΩ
7
VF LPF1
Vocal fader mode LPF capacitor
4.5V
23.5kΩ
8
VF LPF2
Vocal fader mode LPF capacitor
4.5V
70.5kΩ
9
VF LPF3
Vocal fader mode LPF capacitor
4.5V
EF (NPN), 15kΩ
10
GND
Ground
0.0V
—
11
ECHO LEVEL CTRL Microphone off (ground to 0.1Vcc) / echo level adjustment (0.2Vcc to Vcc)
12
LOOP GAIN CTRL
13
EXP DET
14
EXP DET CT
15
EXP BF IN
Loop attenuation ratio setting
Expand detection wave
Expand attack / recovery time setting
Attack R = 5.6kΩ , recovery R = 85.6kΩ
BF input
—
∗
∗
4.5V
50kΩ
—
—
4.5V
B (NPN)
—
16
DLY BF OUT
LPF BF output (EXP)
4.5V
EF (NPN)
17
DLY BF NF IN
LPF BF negative feedback input (EXP)
4.5V
B (NPN)
18
CMP BF OUT
LPF BF output (CMP)
4.5V
EF (P - P)
19
CMP BF NF IN
LPF BF negative feedback input (CMP)
4.5V
B (NPN)
20
CMP OUT
Compression output
4.5V
EF (NPN)
21
CMP DET CT
—
—
22
CMP DET
4.5V
60kΩ
23
VCC
24
BIAS
25
Compression attack / recover time setting
Attack R = 5.6kΩ, recovery R = 85.6kΩ
Compression detection wave
VCC
9.0V
—
Bias and capacitor for ripple rejection
4.5V
23.5kΩ
MIC AMP NF
Microphone amplifier negative feedback
4.5V
2kΩ
26
MIC AMP IN
Microphone amplifier input
4.5V
100kΩ
27
ALC DET
ALC attack / recovery time setting
—
220Ω
28
ALC DET LEVEL
ALC level setting
—
B (PNP)
29
VO DET LEVEL
Microphone amplifier input detection level setting
—
B (PNP)
30
VO DET
Microphone amplifier input detection attack / recover time setting
—
1kΩ
31
NO / VC CTRL
Line output switching (NORMAL / VOCAL CUT)
—
∗
32
L / ST / R CTRL
Line output switching (LEFT / STEREO / RIGHT)
2.5V
∗
Note: Pin type EF: emitter follower, P-P: push-pull, B: base
For pins marked with an asterisk (∗), refer to Input and output equivalent circuit.
All figures are designed values based on the measurement circuit in Fig. 1 (where Vcc = 9.0V), and are not guaranteed standards.
3
Multimedia ICs
BA7726AS / BA7726AFS
•Input / output circuits
L / VF / R CTRL
MUTE CTRL
VCC
VCC
39k
39k
1.7V
39k
3.3V
2.5V
4
150k
3
ECHO LEVEL CTRL
LOOP GAIN CTRL
VCC
12
11
85k
39k
0.6 × VCC
39k
0.6 × VCC
0.8 × VCC
0.8 × VCC
15k
NO / VC CTRL
L / ST / R CTRL
VCC
VCC
49.5k
39k
31
39k
39k
3.3V
33k
32
∗ All figures are designed values, and are not guaranteed standards.
4
1.7V
Multimedia ICs
BA7726AS / BA7726AFS
•Electrical characteristics (unless otherwise noted, Ta = 25°C, Vcc = 9.0V)
Parameter
Supply current
Symbol
Min.
Typ.
Max.
Unit
ICC
5.5
8.4
12.7
mA
No input
Conditions
dBV
VIN = – 20.0dBV
〈LINE THROUGH〉 INPUT : LINE IN, OUTPUT : LINE OUT
Line through output level
VOLL
– 9.0
Line through output distortion
THDLL
—
Line through max. output level
VOMLL
+ 7.8
Line through noise level
VONLL
Interchannel crosstalk
Mute level
– 8.0
– 7.0
0.026
0.2
%
+ 10.0
—
dBV
—
– 100
– 85
dBV
CTLL
—
– 85
—
dBV
MT
—
– 100
– 85
dBV
VIN = – 20.0dBV∗1
MIC OFF (VECHO = 0.1 × VCC)
THD = 1%∗1
No input, Rg = 1kΩ∗2
MIC OFF (VECHO = 0.1 × VCC)
VIN – 12dBV, Rg = 1kΩ∗2
MIC OFF (VECHO = 0.1 × VCC)
VIN = – 12dBV, Rg = 1kΩ∗2
MIC OFF (VECHO = 0.1 × VCC)
MUTE (VMUTE = H)
〈VOCAL CUT MODE〉 INPUT : LINE IN, OUTPUT : LINE OUT
Through mode output level
VOLLV
– 1.0
0.0
+ 1.0
dBV
Vocal suppression ratio 1
VOLL1
– 1.0
0.0
+ 1.0
dB
VIN = – 12dBV (single ch. in.),VOCAL FADER
(VLSTR = H, VLVFR = OPEN, VNOVC = OPEN)
Vocal suppression ratio 2
VOLL2
—
– 35
– 28
dB
VIN = – 12dBV (dual ch.in.),VOCAL FADER
(VLSTR = H, VLVFR = OPEN, VNOVC = OPEN)
VIN = – 12dBV
〈MIC THROUGH〉 INPUT : MIC AMP IN, OUTPUT : LINE OUT
Microphone through output level
VOML
– 9.9
– 8.4
– 6.9
dBV
VIN = – 38dBV
Microphone through
equivalent input noise
VONML
—
– 117
– 102
dBV
Rg = 1kΩ∗2
Microphone input crosstalk
CTML
—
– 92
– 77
dBV
VIN = – 30dBV∗2
MIC OFF (VECHO = 0.1 × VCC)
ALC level
VOAML
+ 5.1
+ 6.6
+ 8.1
dBV
V28 = 2.9V
dBV
VIN = – 38dBV
〈COMPRESS〉 INPUT : MIC AMP IN, OUTPUT : CMP BF OUT
Compress output level
VOMC
– 5.5
– 3.5
– 1.5
Compress characteristics
CMP
—
+ 5.2
—
dB
VIN = – 43dBV → – 33dBV
Output level differential
〈EXPAND〉 INPUT : DLY BF IN, OUTPUT : LINE OUT
Expand output level
VODL
– 9.4
– 7.4
—
dBV
Expand characteristics
EXP
—
+ 19.4
—
dB
VIN = – 9dBV → + 1dBV, Output level differential
Echo EVR attenuation ratio
∆VODL
—
– 50
– 40
dB
VIN = – 4dBV and when VIN = Vodl
ECHO LEVEL = Min. (VECHO = 0.2 × VCC)
– 4.4
– 2.4
—
dBV
—
– 29
—
dB
VIN = – 4dBV
〈Loop〉 INPUT : DLY BF IN, OUTPUT : CMP BF OUT
Loop output level
VODC
Loop EVR attenuation ratio
∗1
∆VODC
VIN = – 4dBV
VIN = – 4dBV and when VIN = Vodc
LOOP GAIN = Min. (VLOOP = 0.2 × VCC)
Unless otherwise noted, mode settings are as follows.
MUTE (VMUTE = GND), STEREO (VNOVC = GND, VLSTR = OPEN, VLVFR = OPEN)
ECHO LEVEL = Max. (VECHO = VCC), LOOP GAIN = Max. (VLOOP = VCC)
∗2
Signal frequency : 1kHz,
∗1 : B.W. = 0.4 ~ 30kHz, ∗2 : DIN
AUDIO
All parameters conform to the Measurement circuit diagram.
5
Multimedia ICs
Parameter
BA7726AS / BA7726AFS
Symbol
Min.
Typ.
Max.
Unit
Mute holding voltage (4pin)
VMUTE – L
GND
—
0.5
V
Mute holding voltage (4pin)
VMUTE – H
4.5
—
5.0
V
[ Control holding voltage ]
〈MUTE CTRL (4pin)〉
〈NO / VC CTRL (31pin)〉
Normal mode holding voltage
VNOVC – L
GND
—
0.3 × VCC
V
VOCAL CUT mode holding voltage
VNOVC – H
0.5 × VCC
—
VCC
V
〈L / ST / R CTRL (32pin)〉
Left mode holding voltage
VLSTR – L
GND
—
0.5
V
Stereo mode holding voltage
VLSTR – M
2.2
—
2.8
V
Right mode holding voltage
VLSTR – H
4.5
—
5.0
V
〈L / VF / R CTRL (3pin)〉
Left mode holding voltage
VLVFR – L
GND
—
0.5
V
VOCAL FADER mode holding voltage
VLVFR – M
2.2
—
2.8
V
Right mode holding voltage
VLVFR – H
4.5
—
5.0
V
〈ECHO LEVEL CTRL (11pin)〉
6
MIC OFF holding voltage
VECHO – L
GND
—
0.1 × VCC
V
MIC ON holding voltage
VECHO – H
0.2 × VCC
—
VCC
V
Conditions
Multimedia ICs
BA7726AS / BA7726AFS
28
VOCAL
DET
26
25
24
23
4
5
0.1µ
6
VR
7
47k
10k
47k
18k
1µ
+
18k
CMP BF OUT
DLY BF IN
1k
8
–
+
9
10
EXPAND
11
12
13
14
15
16
+
LINE IN L
0.068µ
VLOOP
1k
0.1µ 0.47µ
VECHO
1k
LINE IN R
VMUTE
17
+ –
0.015µ
VLVFR
LINE OUT L
LINE OUT R
10k
18
VR
0.1µ
4700p 4700p
10k
220p
19
COMPRESS
+
3
20
1µ
5600p
–
SW
2
21
VOCAL
FADER
+
+
2.2µ 2.2µ
+
+
3900p
VR
ALC
OUTSW
1
22
18k
+
0.1µ
+
22µ
1µ
0.1µ
47µ
+
27
39k
18k
39k
29
A
220p
30
VCC 9V
MIC AMP IN
31
2.2M
1k
32
0.47µ
8.2k 6.8k
3.3k
33µ
+
5600p 3900p
100µ
1k
+
100k
VNOVC
VLSTR
•Measurement circuit
Fig. 1
7
Multimedia ICs
BA7726AS / BA7726AFS
operation
•(1)Circuit
MUTE CTRL (pin 4)
(3) ECHO LEVEL CTRL and MIC ON / OFF SW (pin 11)
• Between Vcc and 0.2 × Vcc: Controls echo signal
mixing ratio
Between Vcc and GND : Turns microphone input
sound (pin 26) to LINE OUT on and off
• Controls line muting.
VMUTE (4pin)
L
H
MUTE
MUTE
VECHO (11pin)
VNOVC (31pin)
L
H
NORMAL
VOCAL CUT
NORMAL
: Normal output mode. Controlled by pin 32.
VOCAL CUT : Used to erase or attenuate vocals in
multiplexed karaoke recordings and
normal stereo music recordings.
Controlled by pin3.
VCC ~ 0.2 × VCC
0.1 × VCC ~ GND
MIC ON and ECHO LEVEL CTRL
MIC OFF
LINE OUT Attenuation. : ATT (dB)
(2) OUTPUT CTRL (pins 3, 31, 32)
• LINE OUT output is controlled with pins 3, 31 and 32.
(Microphone mixing is controlled with pin 11.)
1) NO / VC CTRL (pin 31)
• Used to select the NORMAL and VOCAL CUT modes.
MIC AMP IN ~ LINE OUT
(VIN = – 38dBV, f = 1kHz)
0
DLY BF IN ~ LINE OUT
(VIN = – 4dBV, f = 1kHz)
– 50
– 100
0
0.5
VECHO (11pin) P.P ratio : VECHO / VCC
1.0
Fig. 2 LINE OUTattenuation ratio vs. Vecho (11pin)
partial pressure ratio
∗ These figures are for standard samples and
2) L / ST / R CTRL (pin 32)
• Controls LINE OUT output in the NORMAL mode.
LEFT
L
M (OPEN)
H
LEFT
STEREO
RIGHT
: LINE IN L input is output to LINE OUT L / R.
STEREO : LINE IN L / R input is output to LINE OUT L / R without modification
RIGHT
: LINE IN R input is output to LINE OUT L / R.
3) L / VF / R CTRL (pin 3)
• Controls LINE OUT output in the VOCAL CUT mode.
VLVFR (3pin)
LEFT
L
M (OPEN)
H
LEFT
VOCAL FADER
RIGHT
: For recordings in which the left channel is karaoke
and the right channel is for vocals (with karaoke).
VOCAL FADER : Attenuates the vocals from normal stereo recordings.
RIGHT
: For recordings in which the right channel is karaoke
and the left channel is for vocals (with karaoke).
∗ When Vnovc = L, V
LVFR = DON ' T CARE
When Vnovc = H, VLSTR = DON ' T CARE
8
(4) LOOP GAIN CTRL (pin 12)
• Adjusts the loop gain (pins 17 and 18).
CMP BF OUT Attenuation. : ATT (dB)
VLSTR (32pin)
are not guaranteed standards.
DLY BF IN ~ CMP BF OUT
(VIN = – 4dBV, f = 1kHz)
0
VCC = 9.0V
– 25
– 50
0
0.5
VLOOP (12pin) P.P ratio : VECHO / VCC
1.0
Fig. 3 CMP BF OUT attenuation ratio vs. Vloop
(pin 12) partial pressure ratio
∗ These figures are for standard samples and
are not guaranteed standards.
Multimedia ICs
BA7726AS / BA7726AFS
(5) LPF
• Use the internal operational amplifier and an
attached capacitor and resistor to configure a tertiary
LPF for anti-aliasing and smoothing.
C1
C2
R3
R1
TO BU9252
R2
R1
C2
C3
R1
FROM BU9252
19
18
17
R2
R1
C1
R3
+ –
C3
+ –
20
16
Fig. 4 LPF
LPF constant examples (VCC = 9.0V)
LPF constant
Cutoff frequency
R1
R2
R3
C1
C2
C3
Pass band gain
2kHz
22kΩ
56kΩ
47kΩ
6800pF
4700pF
270pF
0.6dB
3kHz
18kΩ
47kΩ
39kΩ
5600pF
3900pF
220pF
0.7dB
4kHz
15kΩ
39kΩ
33kΩ
4700pF
3300pF
180pF
0.8dB
∗ CMP OUT (pin 20) output is positively correlated with Vcc. When Vcc is a voltage other than 9.0V, set the pass band gain so that maximum CMP side LPF output
(input to BU9252) is 5Vp-p. Make sure that the EXP side LPF constant does not exceed the load drive capability (minimum = 0.3mA, typical 0.5mA).
(6) Vocal fader function
• After the synchronous component of the left and
right channels is eliminated, LPF output is added to
the signal, which is then output (see figure below).
The vocal component is difficult to remove from certain types of sources.
–
1
× (VCC – V28) [Vrms],
2× 2
1.0 ⬉ V28 ⬉ 0.85 × (VCC – 1.0), at LINE OUT
VOAML ⱌ
TO OUTSW
+
LPF
5
6
7
8
between -4dBV and +9dBV, and is determined by the
voltage impressed on pin 28 (V28, set with resistive
division between Vcc and the ground). ALC level is
calculated with the following equation, although slight
error occurs as V28 approaches VCC.
9
C1
+ 10
VCC = 9.0V
C2
at LINE OUT (f = 1kHz)
Fig. 5 Vocal fader block
LPF constant examples
Cutoff frequency
LPF constant
C1
C2
100Hz
0.022µF
0.1µF
150Hz
0.015µF
0.068µF
200Hz
0.01µF
0.047µF
∗ C1 and C2 are only necessary when using the vocal fader function.
(7) ALC level
• When Vcc is 9.0V, ALC level can be set roughly
ALC LEVEL : VOAML (dBV)
LINE LINE
IN R IN L
+5
0
Set within this range
–5
– 10
0
5
Pin 28 voltage: V28 (V)
10
Fig. 6 ALC level vs. pin 28 voltage
∗ These figures are for standard samples and
are not guaranteed standards.
9
BA7726AS / BA7726AFS
Microphone amplifier input
detection level : V ODET (dBV)
Multimedia ICs
(8) Microphone input detection function
• This function detects the signal input to MIC AMP IN
(pin 26) and outputs it to pin 30.
Pin 30 output
No signal input to MIC AMP IN (pin 26)
GND
Signal input to MIC AMP IN (pin 26)
VCC – 1.0V
• The detection level is determined by the voltage
impressed on pin 29 (V29, set with resistive division
between Vcc and the ground) and is calculated with
the following equation, although slight error occurs
as V28 approaches ground.
Set within this range
– 20
VCC = 9.0V
at MIC AMP IN (f = 1kHz)
– 70
5
Pin 29 voltage: V29 (V)
0
10
Fig. 7 Microphone amplifier input detection level vs.
pin 29 voltage
∗ These are figures for standard samples and
are not guaranteed standards.
1
× V29) [Vrms],
2× 2
0.5 ⬉ V29 ⬉ 0.85 × (VCC – 1.0), at MIC AMP IN
VODET ⱌ 0.03 × (
VCC 5V
LINE IN L
LINE IN R
3900p
14
56k
0.068µ
10k
10k
2.7k
ECHO
LEVEL
18
17
16
15
14
4
TEST
CIRCUIT
2
1
LOOP GAIN
BA7726AFS
8bit
D/A
3
16
8
0.015µ
Fig.8
10
15
+
13
BU9252F
f = 455kHz
13
12
12
11
11
10
10
8 × 2k SRAM
9
+
ADRRESS COUNTER
MAIN TIMING
8
1µ
+
9
7
EXPAND
0.1µ
+
VR
MIC ON / OFF
6
0.1µ
5
0.1µ
4
MUTE CTRL
2.2µ
2.2µ
3
L / VF / R
LINE OUT L
LINE OUT R
2
–
–
VR
SW
+
17
0.1µ
5
+
COMPRESS
8bit
A/D
S
and
H
18k
220p
18
6
–
VOCAL
FADER
1
19
VR
ALC
OUTSW
+
20
7
21
10µ
22
18k
23
5600p
24
5600p
0.47µ
VCC 9V
25
47k
26
39k
VOCAL
DET
27
47k
220p
28
18k
3900p
+
29
1µ
+
+
30
+
0.47µ
31
+
0.1µ
32
+
1000p
39k
18k
+
47µ
+
1µ
0.1µ
0.1µ
L / ST / R
NO / VC CTRL
MIC AMP IN
•Application example
Multimedia ICs
BA7726AS / BA7726AFS
notes
•(1)Operation
LINE OUT (pins 1 and 2) signal processing
• Be sure to attach a capacitor for phase correction to
the LINE OUT pins.
+
1
LINE OUT R
4700p
+
2
LINE OUT L
4700p
Fig. 9
(2) Setting the loop gain
• Set the LPF constant and pin 12 control voltage so
that the loop gain (1st echo wave / 2nd echo wave)
does not exceed 1. Be particularly careful of peaking near the LPF cutoff point.
(3) ALC function and microphone amplifier input
detection function
• Refer to items 7 and 8 in “Circuit description.” When
these functions are not used, be sure to ground pins
27 and 28 (the ALC function) and pins 29 and 30
(microphone amplifier input detection function).
•External dimensions (Units: mm)
BA7726AS
BA7726AFS
28.0 ± 0.3
13.6 ± 0.2
17
17
1
16
0.15 ± 0.1
7.8 ± 0.3
16
32
5.4 ± 0.2
1
0.3 ± 0.1
1.778
0.5 ± 0.1
SDIP32
1.8 ± 0.1
10.16
0.11
0.51Min.
3.2 ± 0.2 4.7 ± 0.3
8.4 ± 0.3
32
0.8
0.36 ± 0.1
0.3Min.
0.15
0° ~ 15°
SSOP-A32
11