1148.pdf

TA8210AH / AL

TOSHIBA Bipolar Linear Integrated Circuit Silicon Monolithic

TA8210AH,TA8210AL

20W BTL × 2ch Audio Power Amplifier

The thermal resistance θj−T of TA8210AH, TA8210AL package

designed for low thermal resistance, has a high efficiency of heat

radiation.

The temperature rise of chip can be reduced, and the influence

from the degradation of the features due to the temperature rise

at the high output can also be reduced.

This stereo audio power IC, designed for car audio use, has two

built−in channels to reduce the characteristic difference between

L and R channels.

In addition, the functions of stand−by and muting, and a variety

of protection circuits are involved.

Features

Low thermal resistance

: θj−T = 1.5°C / W (infinite heat sink)

High power

: P OUT (1) = 22W (typ.) / channel

(V CC = 14.4V, f = 1kHz, THD = 10%, R L = 4Ω)

P OUT (2) = 19W (typ.) / channel

(V CC = 13.2V, f = 1kHz, THD = 10%, R L = 4Ω)

Weight

HZIP17−P−2.00: 9.8g (typ.)

HSIP17−P−2.00: 9.8g (typ.)

Low distortion ratio: THD = 0.04% (typ.) (V CC = 13.2V, f = 1kHz, P OUT = 1W, R L = 4Ω, G V = 50dB)

Low noise: V NO = 0.30mV rms (typ.) (V CC = 13.2V, R L = 4Ω, G V 50dB, R g = 0Ω, BW = 20Hz~20kHz)

Built−in stand−by function (with pin(4) set at low, power is turned off.): I SB = 1µA (typ.)

Built−in muting function (with pin(1) set at low, power is turned off.): V (mute) = 1V (typ.)

Built−in various protection circuits

Protection circuits: Thermal shut down, Over voltage, Out→V CC short, Out→GND short and Out−Out short.

Operating supply voltage: V CC = 9~18V

2002-10-30

TA8210AH / AL

Block Diagram

TA8210AH, TA8210AL (G V = 50dB)

Cautions And Application Method

(description is made only on the single channel.)

1. Voltage gain adjustment

This IC has the amplifier construction as shown in Fig.1. The pre

amp (amp 1) is provided to the primary stage,

and the input voltage is amplified by the flat amps, amp 3 and amp 4 of each channel through the phase amp.

(Amp 2).

Since the input offset is prevented by pre

amp when V CC is set to on, this circuit can remarkably reduce the pop

noise.

2002-10-30

TA8210AH / AL

The total closed loop gain G V of this IC can be obtained by expression below when the closed loop voltage gain of

amp 1 is G V1 .

R2)

..... (1)

(dB)

The closed loop voltage gain of power amp, amp 3

and amp 4 is fixed at G V3 ≒ G V4 = 20dB.

Therefore, the total closed circuit voltage gain G V is

obtained through BTL connection by the expression

below.

G V = G V1 + G V3 + 6 (dB) ............... (2)

For example, when R f = 0Ω, G V is obtained by the

expressions (1) and (2) as shown below.

G V ≒ 24 + 20 + 6 = 50dB

The voltage gain is reduced when R f is increased. (Fig.2)

With the voltage gain reduced, since (1) the oscillation

stability is reduced, and (2) the pop noise changes when

V CC is set to on, refer to the items 3 and 4.

Fig.2

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 2.1V (3V BE .),

and the power supply current is about 1µA (typ.) at the

stand

by state.

Pin(4) control voltage : V (SB)

Stand

Power

V (SB) (V)

Off

0~2

Off

3~V CC

Fig.3 With pin(4) set to high, power is on.

Advantage of stand

by SW

(1) Since V CC can directly be controlled to on / 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.

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TA8210AH / AL

3. Preventive measure against oscillation

For preventing the oscillation, it is advisable to use C 4 , the condenser of polyester film having small

characteristic fluctuation of the temperature and the frequency.

The resistance R to be series applied to C 4 is effective for phase correction of high frequency, and improves the

oscillation allowance.

Since the oscillation allowance is varied according to the causes described below, perform the temperature test to

check the oscillation allowance.

1) Voltage gain to be used (G V setting)

(2) Capacity value of condenser

(3) Kind of condenser

(4) Layout of printed board

In case of its use with the voltage gain G V reduced or with the feedback amount increased, care must be taken

because the phase

inversion is caused by the high frequency resulting in making the oscillation viably

generated.

4. Input offset prevention circuit at V CC →on

Having Pre

Amp (Amp 1) mounted on the primary stage, this IC contains the circuit for making the Amp 1 input

voltage and the NF terminal voltage equipotential.

Therefore, the offset voltage produced at the input stage is suppressed to prevent the pop noise at V CC →on. The

capacity values of the input and NF condenser (C 1 and C 2 ) shall be set according to the gain to be used.

(Reference) (A) At G V = 50dB (R f = 0Ω)

C 1 = 4.7µF, C 2 = 47µF

(B) At G V = 40dB (R f = 470Ω)

C 1 = 3.3µF, C 2 = 33µF

2002-10-30

TA8210AH / AL

5. Muting function

Through setting pin(1) (mute terminal) at about 1V or less, muting becomes possible.

The interval circuit of IC is shown in Fig.4.

When pin(1) is set to low, Q1 and Q2 are turned to on, the charge of the ripple condenser is discharged and the

bias is cut. The mute amount of 60dB or over can be obtained.

Since this muting function rapidly discharge the charge of the ripple filter capacitor of pin(8), the pop noise is

generated by the DC fluctuation of the bias section.

Therefore, this muting function is not appropriate to the audio muting but it is effective in muting at V CC →on.

6. External part list and description

Influence

Recom

Sym

mended

Value

Feature

Remarks

Smaller Than

Recommended Value

Larger Than

Recommended Value

bol

Related to gain.

Refer to item 4.

C 1

4.7µF

DC blocking

Related to pop noise at V CC →on.

Determination of low cut

off frequency.

Feedback

condenser

C 2

47µF

C 2 =

・

Ripple

reduction

Time constant is small

at V CC →on or off.

Time constant is large

at V CC →on or off.

C 3

220µF

Oscillation

prevention

Made liable to

oscillate.

C 4

0.12µF

Oscillation allowance.

Refer to item 3.

For filtering power supply hum and ripple.

Large at using AC rectified power supply.

Small at using DC power supply.

C 5

1000µF

Ripple filter

Oscillation

prevention

Oscillation allowance improved.

Noise reduction

C 6

1000 P F

Refer to item 3.

2002-10-30

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