TDA7404 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

TDA7404

Car radio signal processor

STMicroelectronics 

TDA7404

Description of functionality

4.9

External AC - coupling

TDA7404 has external AC coupling terminals which can be selected one of two positions

behind the mixing stage or bass filter.

Figure 16. External AC coupling

Input

ACOUT

SW1

a

b

Mixing

Stage

SW3

SOUND

EFFECTS

Volume & Filter

ACIN

SW2

a

b

ACC selector

SW4

Speaker

The external AC coupling is selected in position of four switches controlled by the lower 2bit

in the Others selection (seeTable 6).

Table 6.

D1

X

0

1

Others selection

D0

Switch position

0 SW3 = ON, SW4 = ON (selected internal pass), SW1 = b, SW2 = open

1 SW3 = OFF, SW4 = ON, SW1 = a, SW2 = a

1 SW3 = ON, SW4 = OFF, SW1 = b, SW2 = b

4.10

4.11

Speaker attenuator

Due to practical aspects the steps in the speaker-attenuator are not linear over the full

range. At attenuations more than 24 dB the steps increase from 1.5 dB to 10 dB (please see

data byte specification).

Subwoofer attenuator

The Subwoofer output is a single ended stereo output. The attenuator is exactly the same

like the other speakers.

21/35

Share Link: