TDA7513T_07 Datasheet, PDF (34/84 Pages) STMicroelectronics – Single chip FM/AM tuner with stereo decoder and audio processor

Functional description
TDA7513T
3.4.10
3.4.11
3.4.12
3.4.13
3.4.14
3.4.15
3.4.16
3.4.17
3.4.18
3.4.19
DC Mode
In this mode the DC gain is increased by 5.1dB. In addition the programmed center
frequency and quality factor is decreased by 25%: this can be used to realize different
center frequencies or quality factors with respect to the values listed in the "BASS" section.
MID
There are 3 parameters programmable in the mid filter stage (see Figure 9, 10 and 11):
Attenuation
Figure 9 shows the attenuation as a function of frequency at a center frequency of 1kHz.
Center frequency
Figure 10 shows the four possible center frequencies: 500Hz, 1kHz, 1.5kHz and 2kHz.
Quality factor
Figure 11 shows the two possible quality factors (1 and 2) at a center frequency of 1kHz.
TREBLE
There are two parameters programmable in the treble filter stage (see Figure 12, 13):
Attenuation
Figure 12 shows the attenuation as a function of frequency at a center frequency of
17.5kHz.
Center frequency
Figure 13 shows the four possible Center Fre-quencies: 10, 12.5, 15 and 17.5kHz.
AC coupling
In some applications additional signal manipulations are desired such as surround-sound
processing or more extensive band equalizing. For this purpose a AC-Coupling is placed
before the Speaker-attenuators, which can be activated or internally shorted by Bit7 in the
APSD data byte 0. The input impedance of the AC Inputs is 25kΩ. The external AC coupling
is advised for those applications where very low-level "pop" performance is a must.
Speaker attenuator
The speaker attenuators have exactly the same structure and range as the Volume stage.
3.5
Stereo decoder
The stereo decoder part of the present device (see Figure 14) contains all functions
necessary to demodulate the MPX signal such as pilot tone-dependent MONO/STEREO
switch as well as "stereoblend" and "highcut" functions.
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