TDA7410ND

Description of stereodecoder

21/34

To adjust the external LEVEL voltage to the internal range two values must be defined: the

LEVEL gain LG and VSBL. To adjust the voltage where the full channel separation is

reached (VST) the LEVEL gain LG has to be defined. The following equation can be used to

estimate the gain:

The gain can be programmed through 4 bits in the "Level Gain" byte. The MONO voltage

VMO (0dB channel separation) can be choosen selecting 33, 42, 50 or 58% of REF5V.

Figure 14.

Relation between internal and external LEVEL voltage and setup of Stereoblend

6.8

Highcut Control

The highcut control setup is similar to the stereoblend control setup : the starting point

VHCH can be set with 2 bits to be 42, 50, 58 or 66% of REF5V whereas the range can be

set to be 17 or 33% of VHCH (see Figure 15).

Figure 15.

Highcut characteristics

L

G

REF5V

Field strength voltage STEREO

[]

-----------------------------------------------------------------------------------------------

=

INTERNAL

VOLTAGES

t

D97AU639

VSBL

REF 5V

SETUP OF VST

INTERNAL

VOLTAGES

t

33%

REF 5V

SETUP OF VMO

LEVEL

LEVEL INTERN

FIELDSTRENGHT VOLTAGE

VST

VMO

LEVEL INTERN

42%

50%

58%

VSBL

VST

VMO

FIELDSTRENGHT VOLTAGE

LOWPASS

TIME CONSTANT

D97AU640

FIELDSTRENGHT

VHCH

VHCL

3

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