TEA6322T Philips Semiconductors, TEA6322T Datasheet - Page 27

• Manufacturer Part Number: TEA6322T
• Description: Sound fader control circuit
• Manufacturer: Philips Semiconductors

Philips Semiconductors
Loudness filter calculation example
Figure 15 shows the basic loudness circuit with an
external low-pass filter application. R1 allows an
attenuation range of 21 dB while the boost is determined
by the gain stage V
range of +20 to 12 dB.
Defining f
change while switching loudness on/off. The external
resistor R3 for f
R3 = 3.2 k is generated.
For the low-pass filter characteristic the value of the
external capacitor C1 can be determined by setting a
specific boost for a defined frequency and referring the
gain to G
For example: 3 dB boost at f = 1 kHz
G
If a loudness characteristic with additional high frequency
boost is desired, an additional high-pass section has to be
included in the external filter circuit as indicated in the
block diagram. A filter configuration that provides
AC coupling avoids offset voltage problems.
1995 Dec 19
R3
------------ -
j C
v
Sound fader control circuit
1
= G
=
1
R1
v(ref)
=
v
ref
-------------------- -
1 10
------------------------------------------------------------- -
at f
R1
+ 3 dB = 18 dB; f = 1 kHz and C1 = 100 nF.
10
–
as the frequency where the level does not
ref
G
------ -
20
+
ref
v
G
------ -
20
as indicated above.
R3
v
1 10
. With G
2
–
. Both result in a loudness control
can be calculated as:
10
G
------ -
20
v
G
------ -
20
v
v
= 21 dB and R1 = 33 k ,
–
R3
27
handbook, halfpage
C1
R3
C KVL
11
12
Fig.15 Basic loudness circuit.
V 1
0 dB
33 k
R1
Preliminary specification
V 2
TEA6322T
R2
MHA092