MAX5406 MAXIM [Maxim Integrated Products], MAX5406 Datasheet - Page 22

• Manufacturer Part Number: MAX5406
• Description: Audio Processor with Pushbutton Interface
• Manufacturer: MAXIM [Maxim Integrated Products]

Audio Processor with Pushbutton Interface
The subwoofer output of the MAX5406 combines and
filters the left and right inputs for output to a subwoofer.
Choose the capacitor values to set the bandpass filter
to frequencies between 15Hz and 100Hz.
Figure 12 shows the subwoofer output stage configura-
tion. The subwoofer output is a monophonic signal pro-
duced by adding the left and the right input signals.
The amplifier of the subwoofer output stage produces a
bandpass response. Use the following formulas to
determine the cutoff frequencies for the bandpass filter:
where R
13.8kΩ, R
C
shown in Figure 12.
22
C_S
______________________________________________________________________________________
is C
_S
CLS
CSUB
is R
f
f
HIGHPASS
LOWPASS
or C
LS
has the nominal value of 10.6kΩ, and
or R
CRS.
=
=
RS
2
The external capacitors are as
2
× ×
and has the nominal value of
× ×
π
π
R
R S
Subwoofer Output
CSUB
_
1
1
×
×
C
C
C S
CSUB
_
Some simple products may not need a variable bass
tone control. It may be desirable for such products
to have a bass-boost pushbutton. Tie BASSUP and
BASSDN together to provide a bass-boost feature.
When tied together, the bass boost is toggled between
0dB and maximum by pressing BASSUP or BASSDN.
Audio sources input to the MAX5406 may not have the
same full-scale voltage swings. Use a resistor in series
with the higher voltage swing input source to reduce
the gain for that input.
For example, to reduce the gain by half, add a 10kΩ
resistor in series with L1_H and R1_H, and a 20kΩ in
series with L1_L and R1_L.
PROCESS: BiCMOS
Applications Information
Unequal Source Levels
Chip Information
Bass Boost