TA8207K
LINEAR INTEGRATED CIRCUIT
APPLICATION INFORMATION
1. ADJUSTMENT OF VOLTAGE GAIN
The voltage gain GV is obtained as follows by R1, R2 and RF in Fig.1.
INPUT
6/7
RF 5/8
R1
45Ω
+
AMP
-
R2
30kΩ
OUTPUT
2/10
RF+R1+R2
GV=20λog
RF+R1
When RF=0Ω
GV=56.5dB(typ.)
When RF=120Ω
GV=45dB(typ.)
Reduction of GV is possible by increasing RF. However, it is recommended to use this at 40dB or over since the
feedback increase is liable to produce oscillation.
2. THERMAL SHUTDOWN CIRCUIT
The built-in thermal shut-down circuit can prevent the destruction of IC that abnormal temperature rise when the
heat radiation is insufficient. The operation temperature is set at radiation fin temperature 175℃, at this temperature
or over the bias is interrupted to prevent the destruction of IC.
3. INPUT STAGE
Below circuit shows the input circuit of this IC.
Q2
INPUT
-+
6/7
Q1
CIN
9
GND
OUTPUT
Q3
30KΩ
2/10
to DRIVER
NF 5/8
to BIAS
It is possible that without input coupling capacitor in the input circuit by use a PNP Transistor, Q1. However, 60mV
max offset voltage is produced at pin (6) and (7). Application after checking volume slide noise is recommended. In
order to cut the volume slide noise, insert the input capacitor (CIN) in series to interrupt the DC component.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
5 of 10
QW-R107-013.E