TDA7718N datasheet(13/40 Pages) STMICROELECTRONICS

13 / 40 page

TDA7718N

Description of the audioprocessor

Doc ID 16502 Rev 1

13/40

Description of the audioprocessor

4.1

Input stages

One quasi-differential stereo input, one full-differential stereo input and maximum five

single-ended inputs are available.

4.1.1

Quasi-differential stereo input (QD1)

The QD input is implemented as a buffered quasi-differential stereo stage with 100 k

Ω input-

impedance at each input. There is -3 dB attenuation at QD input stage.

4.1.2

Single-ended stereo input (SE1, SE2, SE3)

The input-impedance at each input is 100 k

Ω and the attenuation is fixed to -3 dB for

incoming signals.

4.1.3

Full-differential stereo input or single-ended input (FD1/QD2/SE4+SE5)

This device provides a full-differential stereo input stage (FD1) or 2nd quasi-differential

stereo input stage. The full differential is a buffered full-differential stereo stage with 100 k

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 k

Ω. 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.

TDA7718N Datenblatt(PDF) 13 Page - STMicroelectronics