PRECAUTIONS FOR USE AND APPLICATION
1) Input Stage
The input stage of power amplifier is comprised of a PNP differential pair preceded by a PNP emitter follower
which allows DC referencing of the source signal to ground. This eliminates the need for an input coupling capacitor.
However, in case the brush noise of volume becomes a problem, provide serially a coupling capacitor to the input side.
2) Adjustment of Voltage Gain
The voltage gain is fixed at GV=56.5dB by the resistors
(R1 and R2) in IC, however, its reduction is possible
through adding Rf as shown in Figure 1. In this case,
the voltage gain is obtained by the following equation
It is recommended to use this IC with the voltage gain
of GV=40dB or over.
3) Measures Against Oscillation
For the capacitors C6 and C7 to be applied for preventing the oscillation between output terminal and GND, use the polyester film
capacitor having superior quality in high frequency and temperature characteristics, however, since the characteristics of the capacitor
may be different depending on the manufactures or kinds, apply the capacitor after confirmation.
Since the characteristics of the capacitor of the ceramic type are liable to be affected by the temperature and the voltage, use the capacitor
of larger capacity and be sure to perform the thermal test to check the oscillation allowance.
1994. 11. 9
Revision No : 0