TA8227AP

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

5 of 10

www.unisonic.com.tw

QW-R107-021,D

APPLICATION INFORMATION AND APPLICATION METHOD(Cont.)

2. Thermal shut-down circuit

The thermal shut-down circuit is built in for the purpose of preventing the destruction of IC due to the abnormal

temperature rise when the heat radiation is insufficient.

The operation temperature is set at radiation Fin temperature 175

°C (Typ.)

At this temperature or over the bias is interrupted to prevent the destruction of IC.

3. Input stage

The input circuit of this IC is as shown in fig.2. PNP Tr : Q1 is provided in the input circuit so as to make its usage

possible without the input coupling capacitor.

However, at pin 6 and pin 7, max 60mV offset voltage is produced.

Application after checking volume slide noise is recommended.

For cutting the volume slide noise, insert the input capacitor: CIN in series to interrupt the DC component.

2/11

(2/19)

4

(8)

5/8

(9/12)

30kΩ

OUTPUT

INPUT

30kΩ

Pre-GND

45kΩ

To DRIVER

47μF

Q1

Q2 Q3

( ): For SOP-20 Package

6/7

(10/11)

4. Oscillation preventive measures

For oscillation preventive capacitor C6 and C7 between the output terminal and GND, it is recommended to use

polyester film capacitor having good characteristics for temperature and for high frequency.

Since the characteristics of the capacitor is liable to be influenced by the temperature, use this capacitor after the

temperature test to check the oscillation allowance.

In addition, as the position of the electrolytic capacitor has a remarkable influence on the oscillation, connect C10

to Vcc at the nearest possible position from power GND.

At using this application wth the voltage gain reduced, oscillation is liable to be produced. Apply the capacitor after

checking enough for its capacity, type and mounting position.

5. Power ON / OFF switch

There is power ON / OFF switch at Pin1. However, output power is changed by Pin1 supply voltage when Pin1

supply voltage is not same Pin12 supply voltage, after referring to attached date, select Pin1 supply voltage.

6. Input voltage

When the excessive signal is input, turning-up is produced in the clip waveform. The turning-up point is