799

Audio ICs

BA3853BFS

FExternal components

(1)

Mute and loudness circuit components

Select the values for the mute and loudness on / off pin

components to suit the product that you are designing.

The value of the resistor should be 2.2M

Ω or less.

Set the circuit time constant as follows:

When using a switch as illustrated in the circuit diagram,

set the values for C and R in the time-constant circuit as

follows:

V: pin 3 or pin 4 voltage

(2)

External filter circuits

The filter circuits are built using passive components,

and the resistors for both the bass and treble filters are

on the chip. Construct the circuits shown below.

Filter cutoff frequencies

The circuits given above have the following frequency

characteristics.

High-pass filter side

Low-pass filter side

The tone control circuit is designed to give a change of

±15dB (Typ.) for the frequency that you wish to boost or

cut at the peak and bottom of the frequency characteris-

tic. Design the filter with due consideration to the fre-

quency characteristics. The values for the filter given in

the application circuit have been selected to give suffi-

cient boost and cut at f = 100Hz and f = 10kHz.

V = Vreg EXP (

*

t

)

V = Vreg (1

* EXP ( *

t

))

1

2

1

2

=

1

2

1

2

=

1

2

1

2

=

= 80kHz