Toshiba TA8266HQ Description And Application Manual

TOSHIBA Bipola r Linear Integrated Circuit Silicon Monolithic

TA8266HQ

Max Power 35 W BTL × 4 ch Audio Power IC

The TA8266HQ is 4 ch BTL audio power amplifier for car audio

application.

This IC can generate more high power: P
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
over voltage input mode.

Additionally, the AUX amplifier and various kind of protector
for car audio use is built-in.

Features

MAX = 35 W as it

OUT

/GND short and

CC

Weight: 7.7 g (typ.)

TA8266HQ

• High power : P
(V
: P
(V
: P
(V
: P
(V

• Built-in diagnosis circuit (pin 25)

• Low distortion ratio: THD = 0.02% (typ.)

(V

• Low noise: V
(V

• 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

• Operating supply voltage: V

Note 1: Install the product correctly. Otherwise, it may result in break down, damage and/or degradation to the

product or equipment.

Note 2: These protection functions are int ended to avoid some ou tput short circuits or other abnormal conditions

temporarily. These protect functi ons do not warrant to prevent the IC from being damaged.

- In case of the product would be operated with exceeded guaranteed operating ranges, these

protection features may not operate and some output short circuits may result in the IC being
damaged.

MAX (1) = 35 W (typ.)

OUT

= 14.4 V, f = 1 kHz, JEITA max, RL = 4 Ω)

CC

MAX (2) = 31 W (typ.)

OUT

= 13.7 V, f = 1 kHz, JEITA max, RL = 4 Ω)

CC

(1) = 23 W (typ.)

OUT

= 14.4 V, f = 1 kHz, THD = 10%, RL = 4 Ω)

CC

(2) = 20 W (typ.)

OUT

= 13.2 V, f = 1 kHz, THD = 10%, RL = 4 Ω)

CC

= 13.2 V, f = 1 kHz, P

CC

= 0.18 mVrms (typ.)

NO

= 13.2 V, Rg = 0 Ω, GV = 34dB, BW = 20 Hz~20 kHz)

CC

= 9~18 V

CC (opr)

= 5 W, RL = 4 Ω)

OUT

CC

, out to out short, speaker burned

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Block Diagram

TA8266HQ

C1

C1

C6

C1

11

12

16

15

IN1

IN2

AUX IN

IN3

1 20 6

TAB V

CC1VCC2

OUT1 (+)

PW-GND1

OUT1 (−)

OUT2 (+)

PW-GND2

OUT2 (−)

OUT3 (+)

PW-GND3

OUT3 (−)

17

18

19

5

C

9

8

7

5

2

3

3

C

RL

RL

RL

C1

PRE-GND

14

13

IN4

DIAGNOSIS

STBY

10 254 22

2

C

OUT RIP MUTE

OUT4 (+)

PW-GND4

OUT4 (−)

1

R

21

24

23

4

C

RL

: PRE-GND
: PW-GND

Note3: Some of the functional bl ocks, circuits, or constants in the block diagram may be omitted or si mplified for

explanatory purpose.

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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. 1

Input

Figure 1 Block Diagram

The voltage gain of Amp.1 : G
The voltage gain of Amp.2A, B : G
The voltage gain of BLT Connection : G

Therefore, the total voltage gain is decided by expression below.

G

= GV1 + GV2 + G

V

2. Stand-by SW Function

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

(typ.), and the power supply current is about 2

BE

µA (typ.) at the stand-by state.

Control Voltage of pin 4: VSB

= 8 + 20 + 6 = 34dB

V (BTL)

(pin 4)

V1
V2
V (BTL)

Amp. 2A

= 8dB
= 20dB

= 6dB

Amp. 2B

ON

OFF

Power

4

10 kΩ

V

CC

≈ 2VBE

TA8266HQ

to BIAS
CUTTING CIRCUIT

Stand-by Power VSB (V)

ON OFF 0~1.5

OFF ON 3~VCC

Figure 2 With pin 4 set to High,
Power is turned ON

Adjustage of Stand-by SW

(1) Since V

omitted.

(2) Since the control current is microscopic, the switching relay of small current capacity is satisfactory

for switching

can directly be controlled to ON or OFF by the microcomputer, the switching relay can be

CC

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TA8266HQ

A

Large current capacity switch

BATTERY

RELAY

BATTERY

Stand-By V

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
ON/OFF.

The series resistance; R1 must be set up less than 10 kΩ to get enough muting attenuation.

The muting function have to be controlled by a transistor, FET and micro-controller port which has
I

> 250 µA ability.

MUTE

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>

I (100 µA)

I

MUTE (OFF)

22

4

C

V

CC

Small current capacity switch

R1

MUTE

V

V

MUTE

CC

I

V

CC

– Conventional Method –

DIRECTLY FROM

BATTERY

– Stand-by Switch Method –

MICROCOMPUTER

Stand-By

CC

FROM
MICROCOMPUTER

BATTERY

Figure 3

and C4 and these parts is related the pop noise at power

1

20

0

−20

−40

ATT – V

MUTE

10 kΩ 5 kΩ

<Application for pulled up>

I (100 µA)

I

MUTE (OFF)

22

R1

4

C

I

MUTE

V

MUTE

Figure 4 Muting Function

−60

MUTE

VCC = 13.2 V
Po = 10 W
PL = 4 Ω
f = 1 kHz

(V)

−80

Mute attenuation ATT (dB)

−100

0 0.4 0.8 1 1.2 1.6 2 2.4 2.8 3

Point A voltage: V

Figure 5 Mute Attenuation − V

4

(V)

MUTE

2006-04-28

TA8266HQ

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 µ-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.

5. 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.

25

µ-COM

5 V

5 V

IN

AUX-IN

AUX AMP

16

−20dB

Figure 6 AUX Input

20dB AMP.

OUT (+)

OUT (−)

OUTPUT SHORT

PROTECTOR

OVER VOLTAGE

PROTECTOR

pin 25: O pen collector out put (active low)

Q1

GND

Figure 7 Self Diagnosis Output

5.1 In Case of Shorting Output to VCC/GND or Over Voltage Power Supplied

NPN transistor (Q1) is turned on.
Threshold of over voltage protection: V

5 V

25

µ-COM

MEMORY

(Count and record)

= 22 V (typ.)

CC

LED/LCD

ALARM

REGULATOR → OFF

(Flashing)

(Announcement from a speaker.)

Q1 is turned on

(Relay → OFF)

t

5.2 In Case of Shorting Output to Output

NPN transistor (Q1) is turned on and off in response to the input signal voltage.

Figure 8 Application 1

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