TDA7406 datasheet(16/64 Pages) STMICROELECTRONICS

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Description of the audioprocessor part

TDA7406

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Description of the audioprocessor part

4.1

Input stages

In the basic configuration there is a source-Selector with 8 inputs: one pseudo-differential

(CDC), three single ended stereo (MD, CD, Tape), three single-ended mono (PHONE, NAVI,

TIM) plus the “tuner” input. The tuner input takes the signal from either MPX1 or MPX2/AM

pins (through the stereodecoder) see Figure 3.

4.1.1

Pseudo-differential stereo Input (PD)

The PD input is implemented as a buffered pseudo-differential stereo stage with 100k

input-impedance at each input pin. This input is also configurable as single-ended stereo

input (CDC, see pin-out). The common input-pin, PD- features a fast charge switch to speed

up the charge time of external capacitors. This switch is released the first time the input-

selector data-byte (0) is assessed.

4.1.2

Single-ended stereo Inputs, single-ended mono inputs and FM-MPX

input

All single ended inputs have an input impedance of 100k

Ω. The AM-pin can be connected to

the input of the stereo-decoder in order to use the AM-noiseblanker and AM-High-Cut

feature. As input “Tuner” for the input selector either the stereo-decoder output or the AM-pin

is selectable.

4.1.3

Mixing Selector

It is possible to enable/disable the mixing feature (ratio 50%) at the outputs stages between

whichever input source and one of the following signals: Beep, Phone, Navigator and

Tuner/TIM.

4.1.4

Beep Generator

There are four possible selectable beeping frequencies: 600Hz, 780Hz, 1.56KHz and

2.4KHz.

TDA7406 Datasheet(PDF) 16 Page - STMicroelectronics