TDA7720BTR datasheet(14/42 Pages) STMICROELECTRONICS

14 / 42 page

Description of audioprocessor

TDA7720B

14/42

DocID024331 Rev 2

Description of audioprocessor

4.1

Input stage

Two quasi-differential stereo input and three single-ended inputs are available.

4.1.1

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

The input-impedance at each input is 100 k

 and the attenuation is fixed to -3 dB for

incoming signals.

4.1.2

Quasi-differential stereo Input (QD1,QD2)

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

 input-

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

4.1.3

Fast charge

Each differential input pin features a "fast-charge" switch allowing to quickly charge any

external large coupling capacitors upon power-on of the device. When the device is power-

on, the “fast-charge” switches are automatically turn on, for normal operation these switches

need to be released by any programming of byte_0. After that, the “fast-charge” switches

can be turned on/off by setting “fast charge = on/off”.

4.2

Input gain

A 0/3 dB input gain is selectable to compensate the attenuation of input stage.

TDA7720BTR Datasheet(PDF) 14 Page - STMicroelectronics