TDA7404DTR Datasheet, PDF (13/35 Pages) STMicroelectronics – Car radio signal processor

TDA7404
4
Description of functionality
Description of functionality
4.1
Input stages
Most of the input stages have remained the same as in preceding ST-Audioprocessors with
exception of the CD-inputs (see Figure 3). In the meantime there are some CD-players in
the market which have a significant high source-impedance which effects strongly the
common-mode-rejection of the normal differential input stage.
The additional buffer of the TDA7404 Diff:
● input avoids this drawback and offers the full common-mode-rejection even with those
CD-players.
Figure 3. Input stages diagram
D iffi n +
/(SE 4)
Diffgn d
Mon o+
Mon o -
SE1
28k
28k
28k
28k
I n ga in
SE2
SE3
1. It is possible that the Differential input is switched a single ended input (SE4) like SE1.. 3.
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