DESCRIPTION OF THE AUDIOPROCESSOR

PART

Programmable Input Matrix

The programmable input matrix of the TDA7461N

offers several possibilities to adapt the audioproc-

essor to the desired application. In to the stand-

ard application we have:

CD quasi differential

Cassette stereo

Phone differential

AM mono

Stereodecoder input.

The input matrix can be configured by only 2 bits:

bits 3 and 4 of subaddress 0. Basically the bit of

subaddress 13 is fixed by the application and has to

be programmed only once at the startup of the IC.

For many configurations the two bits are also fixed

during one application (e.g. the standard applica-

tion) and a change of the input source can be done

by loading the first three bits of subaddress 0.

In other configurations for some sources a pro-

gramming of bit 3 and 4 of subaddress 0 is nec-

essary in addition to the three source selection

bits. In every case only the subaddress 0 has to

be changed to switch from one source to another.

The following picture shows the input and source

programming flow:

TDA7461

CD QD

CD FD

APPL. 2

APPL. 1

APPL. 3

APPL. 5

APPL. 4

APPL. 6

CD QD

CASSETTE

FM STD

AM MONO

PHONE (D)

CD QD

CASSETTE

FM STD

AM STEREO

PHONE (SE)

CD QD

CASSETTE

FM STD

AM STD

PHONE (D)

CD FD

CASSETTE

FM STD

AM MONO

PHONE (SE)

CD FD

CASSETTE

FM STD

AM STEREO

CD FD

CASSETTE

FM STD

AM STD

PHONE (SE)

D97AU632B

Figure 1. Input Configuration Tree

Note: in AMSTD configuration the AM mono signal is lead through the FM stereodecoder part to use its additional filters and high-cut function.

PIN NUMBER

Appl. No

6

8

9

10

Programming

1)

Phone

Startup:

0/xxx11xxx

AMRIGHT

Startup:

0/xxxx1xxx

FM

AM

Phone

0/xxx11100

0/xxx01011

0/xxx11010

Phone

AMSTD

Startup:

0/xxxx1xxx

FM

AM

Phone

0/xxx11100

0/xxx01100

0/xxx11010

4

Phone

Startup:

0/xxxx0xxx

5

AMRIGHT

Startup:

0/xxxx0xxx

FM

AM

0/xxx10100

0/xxx00011

6

Phone

AMSTD

Startup:

0/xxxx0xxx

FM

AM

Phone

0/xxx10100

0/xxx00100

0/xxx10010

TDA7461N

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