TDA7437N Datasheet, PDF (18/23 Pages) STMicroelectronics – DIGITALLY CONTROLLED AUDIO PROCESSOR

TDA7437N
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TREBLE STAGE
The Treble stage is a simple high pass filter which time constant is fixed by internal resistor (50Kohm typ) and
an external capacitor connected between pins TREB_R/TREB_L and Ground.
IN-OUT PINS
The multiplexer output is available at OUT_R and OUT_L pins for optional connection of external graphic equal-
izer (TDA7316/TDA7317), surround chip (TDA7346) etc. The signal is fed in again at pins IN_L and IN-R. In
case of application without external devices the pins OUT_L/OUT_R and IN_L/IN_R can be left unconnected if
bit D3 byte input selector is forced = 0 (DC connect) instead if bit D3 is kept = 1 an external decoupling capacitor
must be provided between OUTR/INR and OUTL/INR necessary to avoid signal DC jumps, generating "Click-
ing" output noise.The input impedance of the next volume stage is 44Kohm typical (minimum 31Kohm). A ca-
pacitor no lower than 1mF should be used.
INPUT SELECTOR
The multiplexer selector can choose one of the following inputs:
- a differential CD stereo input.
- a mono input.
- four stereo input
The signal fed to the input pins must be decoupled via series capacitors. The minimum allowed value depends
on the correspondent input impeance. For the CD diff input (Zi = 10Kohm worst case ) a Cin = 4.7uF is recom-
mended. For the other inputs (70Kohm worst case,a Cin=1uF is recommended.
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