TDA7718N Datasheet, PDF (13/40 Pages) STMicroelectronics – 3 band car audio processor

TDA7718N
Description of the audioprocessor
4
Description of the audioprocessor
4.1
4.1.1
4.1.2
4.1.3
Input stages
One quasi-differential stereo input, one full-differential stereo input and maximum five
single-ended inputs are available.
Quasi-differential stereo input (QD1)
The QD input is implemented as a buffered quasi-differential stereo stage with 100 kΩ input-
impedance at each input. There is -3 dB attenuation at QD input stage.
Single-ended stereo input (SE1, SE2, SE3)
The input-impedance at each input is 100 kΩ and the attenuation is fixed to -3 dB for
incoming signals.
Full-differential stereo input or single-ended input (FD1/QD2/SE4+SE5)
This device provides a full-differential stereo input stage (FD1) or 2^nd quasi-differential
stereo input stage. The full differential is a buffered full-differential stereo stage with 100 kΩ
input-impedance at each input. When using as QD2 application, it needs to connect the two
QD2G pins together from external and the input impedance at QDG becomes 50 kΩ. This
stage can be also configured as 2 single-ended stereo input stages (SE4 and SE5). The
configuration is done with the input selector control bits and the selection of FD1 and QD2 is
controlled by a separate bit. There is -3 dB attenuation at the input stage. Figure 3 shows
the block diagram of this input stage.
Doc ID 16502 Rev 1
13/40