TA8277H
2002-02-13
1
TOSHIBA Bipolar Linear Integrated Circuit Silicon Monolithic
TA8277H
Max Power 43 W BTL 4 ch Audio Power IC
The TA8277H is 4 ch BTL audio power amplifier for car audio
application.
This IC can generate more high power: P
OUT
MAX = 43 W as it
is included the pure complementary PNP and NPN transistor
output stage.
It is designed low distortion ratio for 4 ch BTL audio power
amplifier, built-in stand-by function and muting function.
Additionally, the AUX amplifier and various kind of protector
for car audio use is built-in.
Features
High power : P
OUT
MAX (1) = 43 W (typ.)
(V
CC
= 14.4 V, f = 1 kHz, JEITA max, R
L
= 4 )
:
P
OUT
MAX (2) = 40 W (typ.)
(V
CC
= 13.7 V, f = 1 kHz, JEITA max, R
L
= 4 )
:
P
OUT
(1) = 28 W (typ.)
(V
CC
= 14.4 V, f = 1 kHz, THD = 10%, R
L
= 4 )
:
P
OUT
(2) = 24 W (typ.)
(V
CC
= 13.2 V, f = 1 kHz, THD = 10%, R
L
= 4 )
Low distortion ratio: THD = 0.02% (typ.)
(V
CC
= 13.2 V, f = 1 kHz, P
OUT
= 5 W, R
L
= 4 )
Low noise: V
NO
= 0.10 mVrms (typ.)
(V
CC
= 13.2 V, R
g
= 0 , G
V
= 26dB, BW = 20 Hz~20 kHz)
Built-in stand-by switch function (pin 4)
Built-in muting function (pin 22)
Built-in AUX amplifier from single input to 4 channels output (pin 16)
Built-in various protection circuit
: Thermal shut down, over voltage, out to GND, out to V
CC
, out to out short
Operating supply voltage: V
CC (opr)
= 9~18 V
Weight: 7.7 g (typ.)
TA8277H
2002-02-13
2
Block Diagram
R
L
R
L
R
L
11
9
8
7
5
2
3
17
18
19
21
24
23
12
15
14
1
20
6
R
L
IN1
IN2
IN3
AUX IN
IN4
13
16
C
1
C
1
C
1
C
1
PRE-GND
10
25
4
22
OUT1 (
+
)
PW-GND1
OUT1 (
-
)
OUT2 (
+
)
PW-GND2
OUT2 (
-
)
OUT3 (
+
)
PW-GND3
OUT3 (
-
)
OUT4 (
+
)
PW-GND4
OUT4 (
-
)
TAB
V
CC1
V
CC2
C
3
R
1
C
4
C
2
: PRE-GND
: PW-GND
STBY
MUTE2
RIP
MUTE
C
5
C
6
C
8
R
2
C
7
TA8277H
2002-02-13
3
Caution and Application Method
(Description is made only on the single channel.)
1. Voltage
Gain
Adjustment
This IC has no NF (negative feedback) terminals. Therefore, the voltage gain can't adjusted, but it makes
the device a space and total costs saver.
The voltage gain of Amp.1
: G
V1
= 0 dB
The voltage gain of Amp.2A, B
: G
V2
= 20 dB
The voltage gain of BLT Connection : G
V (BTL)
= 6 dB
Therefore, the total voltage gain is decided by expression below.
G
V
= G
V1
+ G
V2
+ G
V (BTL)
= 0 + 20 + 6 = 26 dB
2. Stand-by SW Function
(pin 4)
By means of controlling pin 4 (stand-by terminal)
to high and low, the power supply can be set to ON
and OFF. The threshold voltage of pin 4 is set at
about 3V
BE
(typ.), and the power supply current is
about 2 mA (typ.) at the stand-by state.
Control Voltage of pin 4: V
SB
Stand-by Power V
SB
(V)
ON OFF 0~1.5
OFF ON 3~V
CC
Adjustage of Stand-by SW
(1) Since
V
CC
can directly be controlled to ON or OFF by the microcomputer, the switching relay can be
omitted.
(2) Since the control current is microscopic, the switching relay of small current capacity is satisfactory
for switching
Amp. 1
Input
Amp. 2A
Amp. 2B
Figure 1 Block Diagram
Figure 2 With pin 4 set to High,
Power is turned ON
ON
4
OFF
10 k
W
to BIAS
CUTTING CIRCUIT
2V
BE
V
CC
Power
TA8277H
2002-02-13
4
3. Muting
Function
(pin 22)
By means of controlling pin 22 less than 0.5 V, it can make the audio muting condition.
The muting time constant is decided by R
1
, C
4
and C
8
and these parts is related the pop noise at power
ON/OFF.
The series resistance; R
1
must be set up less than 5 kW.
The muting function have to be controlled by a transistor, FET and m-COM port which has I
MUTE
>
50 mA ability.
Conventional Method
V
CC
Large current capacity switch
BATTERY
V
CC
FROM
MICROCOMPUTER
BATTERY
RELAY
V
CC
Small current capacity switch
BATTERY
Stand-By
V
CC
DIRECTLY FROM
MICROCOMPUTER
BATTERY
Stand-By
Stand-by Switch Method
Figure 3
Figure 5 Mute Attenuation
-
-
-
-
V
MUTE
(V)
Point A voltage: VMUTE (V)
ATT V
MUTE
Mut
e
a
tte
nu
ati
o
n A
T
T
(dB
)
R1
=
2.2 k
W
R1
=
5 k
W
VCC
=
13.2 V
Po
=
10 W
RL
=
4
W
f
=
1 kHz
-
100
1.2
1.4
1.6
1.8
2.0 2.2 2.4 2.6 2.8
-
80
-
60
-
40
-
30
-
20
0
-
10
-
90
-
70
-
50
Figure 4 Muting Function
R
1
I (20
m
A)
22
I
MUTE
I
MUTE (OFF)
A
V
MUTE
C
4
25
C
7
TA8277H
2002-02-13
5
4. AUX
Input
(pin 16)
The pin 16 is for input terminal of AUX
amplifier.
The total gain is 0dB by using of AUX amplifier.
Therefore, the m-COM can directly drive the
AUX amplifier.
BEEP sound or voice synthesizer signal can be
input to pin 16 directly.
When AUX function is not used, this pin must be
connected to PRE-GND (pin 13) via a capacitor.
Figure 6 AUX Input
20dB AMP.
IN
OUT (
+
)
OUT (
-
)
16
AUX-IN
-
20dB
AUX AMP
m
-COM
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