196

Audio ICs

BA3308 / BA3308F / BA3308FV

FTotal application circuit

FCircuit operation

(1)

Recording

The channel 1 and 2 amplifier input stages of the BA3308

(pins 8 and 2) can be direct-coupled, and the input cou-

is applied, (see “operation notes”), use the time constant

plication example circuit diagram, or values close to

also the DC bias feedback resistor, and is connected be-

The BA3308 includes a signal rectifier block and elec-

tronic potentiometers required for the ALC. In the signal

rectifier block, a comparator compares the DC output

voltage component of the output stage signal (pins 3 and

approximately 3V), and if it is above this, the comparator

The operating point of the amplifier’s ch1 and ch2 output

comparator goes on, DC signals for electronic poten-

tiometer control are generated, and the ALC starts oper-

ating.

The electronic potentiometers are connected between

the input lines (pins 2 and 8) and GND, and the input sig-

nals is attenuated by the ratio of the electronic potentiom-

5 set the ALC attack and recovery times. The larger the

values of these constants, the longer the recovery time,

time.