TA8266H
TOSHIBA Bipolar Linear Integrated Circuit Silicon Monolithic
TA8266H
Max Power 35 W BTL × 4 ch Audio Power IC
The TA8266H is 4 ch BTL audio power amplifier for car audio
application.
This IC can generate more high power: P
OUT
MAX = 35 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, muting function, and
diagnosis circuit which can detect output to V
CC
/GND short and
over voltage input mode.
Additionally, the AUX amplifier and various kind of protector
for car audio use is built-in.
Weight: 7.7 g (typ.)
Features
·
High power : P
OUT
MAX (1) = 35 W (typ.)
(V
CC
= 14.4 V, f = 1 kHz, JEITA max, R
L
= 4
Ω)
: P
OUT
MAX (2) = 31 W (typ.)
(V
CC
= 13.7 V, f = 1 kHz, JEITA max, R
L
= 4
Ω)
: P
OUT
(1) = 23 W (typ.)
(V
CC
= 14.4 V, f = 1 kHz, THD = 10%, R
L
= 4
Ω)
: P
OUT
(2) = 20 W (typ.)
(V
CC
= 13.2 V, f = 1 kHz, THD = 10%, R
L
= 4
Ω)
·
·
·
·
·
·
·
·
Built-in diagnosis circuit (pin 25)
Low distortion ratio: THD = 0.02% (typ.)
(V
CC
= 13.2 V, f = 1 kHz, P
OUT
= 5 W, R
L
= 4
Ω)
Low noise: V
NO
= 0.18 mVrms (typ.)
(V
CC
= 13.2 V, R
g
= 0
Ω,
G
V
= 34dB, 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 2 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, speaker burned
Operating supply voltage: V
CC (opr)
= 9~18 V
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TA8266H
Block Diagram
C
5
1
TAB
20
V
CC1
6
V
CC2
OUT1 (+)
9
C
1
11
IN1
PW-GND1 8
OUT1 (-)
7
R
L
OUT2 (+)
12
IN2
5
R
L
C
1
PW-GND2 2
OUT2 (-)
3
C
6
16
AUX IN
OUT3 (+)
15
IN3
17
R
L
C
1
PW-GND3 18
OUT3 (-)
19
OUT4 (+)
14
IN4
21
R
L
C
1
PW-GND4 24
OUT4 (-)
23
PRE-GND
13
RIP
10
C
2
STBY
4
DIAGNOSIS
OUT
MUTE
25
22
R
1
C
4
: PRE-GND
: PW-GND
C
3
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2002-02-13
TA8266H
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.
Amp. 2A
Amp. 1
Input
Amp. 2B
Figure 1
Block Diagram
The voltage gain of Amp.1
: G
V1
=
8dB
The voltage gain of Amp.2A, B
: G
V2
=
20dB
The voltage gain of BLT Connection : G
V (BTL)
=
6dB
Therefore, the total voltage gain is decided by expression below.
G
V
=
G
V1
+
G
V2
+
G
V (BTL)
=
8
+
20
+
6
=
34dB
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.
V
CC
ON Power
OFF
4
10 kW
»
2V
BE
to BIAS
CUTTING CIRCUIT
Control Voltage of pin 4: V
SB
Stand-by
ON
OFF
Power
OFF
ON
V
SB
(V)
0~1.5
3~V
CC
Figure 2 With pin 4 set to High,
Power is turned ON
Adjustage of Stand-by SW
(1)
(2)
Since V
CC
can directly be controlled to ON or OFF by the microcomputer, the switching relay can be
omitted.
Since the control current is microscopic, the switching relay of small current capacity is satisfactory
for switching
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TA8266H
Large current capacity switch
BATTERY
RELAY
BATTERY
V
CC
V
CC
– Conventional Method –
FROM
MICROCOMPUTER
Small current capacity switch
BATTERY
DIRECTLY FROM
MICROCOMPUTER
BATTERY
Stand-By V
CC
Stand-By V
CC
– Stand-by Switch Method –
Figure 3
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
and C
4
and these parts is related the pop noise at power
ON/OFF.
The series resistance; R1 must be set up less than 10 kW to get enough muting attenuation.
The muting function have to be controlled by a transistor, FET and micro-controller port which has
I
MUTE
>
250
mA
ability.
Pin 22 terminal voltage has the temperature characteristics of 4.6 V (low temperature) to 3.2 V (high
temperature).
Therefore, it is need to design with attention as using the micro-controller of which operating voltage is
less than 5 V.
Terminal 22 may not be pulled up and shall be controlled by OPEN/LOW.
When it is obliged to do, it must be pulled up via diode, because it has to defend flowing reverse current
to internal circuit of pin 22.
<Recommended Application>
ATT – V
MUTE
20
I (100
mA)
I
MUTE (OFF)
22
C
4
R
1
A
(dB)
10 kW
0
5 kW
Mute attenuation ATT
I
MUTE
V
MUTE
-20
-40
-60
-80
-100
0
0.4
0.8 1 1.2
1.6
2
VCC
=
13.2 V
Po
=
10 W
PL
=
4
W
f
=
1 kHz
2.4
2.8 3
<Application for pulled up>
I (100
mA)
I
MUTE (OFF)
22
C
4
R
1
I
MUTE
V
MUTE
Point A voltage: VMUTE
(V)
Figure 4
Muting Function
Figure 5
4
Mute Attenuation
-
V
MUTE
(V)
2002-02-13
TA8266H
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.
20dB AMP.
IN
OUT (+)
OUT (-)
AUX AMP
m-COM
AUX-IN
16
-
20dB
Figure 6
5.
AUX Input
Diagnosis Output
(pin 25)
This diagnosis output terminal of pin 25 has open collector output structure on chip as shown in Figure 7.
In case diagnosis circuit that detect unusual case is operated, NPN transistor (Q1) is turned on.
It is possible to protect all the system of apparatus as well as power IC protection.
In case of being unused this function, use this IC as open-connection on pin 25.
5V
25
5V
OUTPUT SHORT
PROTECTOR
OVER VOLTAGE
PROTECTOR
Q1
GND
t
Q1 is turned on
pin 25: Open collector output (active low)
Figure 7
5.1
Self Diagnosis Output
In Case of Shorting Output to V
CC
/GND or Over Voltage Power Supplied
NPN transistor (Q1) is turned on.
Threshold of over voltage protection: V
CC
=
22 V (typ.)
5V
m-COM
LED/LCD
ALARM
(Flashing)
(Announcement from a speaker.)
(Relay
→
OFF)
25
REGULATOR
→
OFF
MEMORY (Count and record)
Figure 8
5.2
In Case of Shorting Output to Output
Application 1
NPN transistor (Q1) is turned on and off in response to the input signal voltage.
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