TDA7460ND(2009) View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

TDA7460ND
(Rev.:2009)

Car radio signal processor

STMicroelectronics 

Description of the audio processor part

TDA7460ND

4.2.2

Soft mute

The digitally controlled soft mute stage allows muting/demuting the signal with a I2C bus

programmable slope. The mute process can either be activated by the soft mute pin or by

the I2C bus. The slope is realized in a special S shaped curve to mute slow in the critical

regions (see Figure 8.).

For timing purposes the Bit 3 of the I2C bus output register is set to 1 from the start of

muting until the end of demuting.

Figure 8. Soft mute timing

Obsolete Product(s) - Obsolete Product(s) 4.2.3

1

EXT.

MUTE

+SIGNAL

REF

-SIGNAL

1

I2C BUS

OUT

D97AU634

Time

1. Please notice that a started Mute action is always terminated and could not be interrupted by a change of

the mute signal.

Soft step volume

When volume level is changed often an audible click appears at the output. The root cause

of those clicks could be either a DC offset before the volume stage or the sudden change of

the envelope of the audio signal. With the Soft step feature both kinds of clicks could be

reduced to a minimum and are no more audible (see Figure 9.).

Figure 9. Soft step timing

VOUT

2dB

1dB

-1dB

10ms

Time

-2dB

D97AU635

2. For steps more than 1 dB the soft step mode should be deactivated because it could generate a 1 dB error

during the blend-time

18/49

Share Link: