TEA6323T Philips Semiconductors (Acquired by NXP), TEA6323T Datasheet - Page 27

• Manufacturer Part Number: TEA6323T
• Description: TEA6323T; Sound Fader Control Circuit
• Manufacturer: Philips Semiconductors (Acquired by NXP)

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.
Figure 16 shows an example of the loudness circuit with
bass and treble boost. The calculation of this network is
numeric.
1995 Dec 20
R3
-------------------- -
j
v
Sound fader control circuit
= G
1
=
C1
R1
v(ref)
v
ref
-------------------- -
1 10
at f
=
+ 3 dB = 18 dB; f = 1 kHz and C1 = 100 nF.
10
–
as the frequency where the level does not
------------------------------------------------------------- -
ref
R1
G
------ -
20
ref
v
G
------ -
20
as indicated above.
v
+
. With G
2
R3
. Both result in a loudness control
1 10
–
can be calculated as
10
G
------ -
20
v
v
= 21 dB and R1 = 33 k ,
G
------ -
20
v
–
R3
27
handbook, halfpage
handbook, halfpage
Fig.16 Loudness circuit with bass and treble boost.
C1
R3
20 k
150 nF
C KVL
8.2 nF
2.2 k
220 nF
11
12
Fig.15 Basic loudness circuit.
11
12
V 1
0 dB
33 k
R1
V 1
0 dB
33 k
R1
Preliminary specification
V 2
MHA281
TEA6323T
V 2
R2
MHA092
R2