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TDA7419

5.3.4 Flat Mode

In flat mode the loudness stage works as a 0dB to -15dB attenuator.

5.4

SoftMute

ized in a special S-shaped curve to mute slow in the critical regions (see Figure 8).

For timing purposes the Bit0 of the I2C-bus output register is set to 1 from the start of muting until the end

of demuting.

Figure 8. Sofmute Timing

Note: Please notice that a started Mute-action is always terminated and could not be interrupted by a change of the mute -signal

5.5

SoftStep-Volume

When the volume-level is changed audible clicks could appear at the output. The root cause of those clicks

could either be a DC-Offset before the volume-stage or the sudden change of the envelope of the audi-

osignal. With the SoftStep feature both kinds of clicks could be reduced to a minimum and are no more

audible. The blend-time from one step to the next is programmable in four steps.

Figure 9. SoftStep Timing

Note: For steps more than 0.5dB the SoftStep mode should be deactivated because it could generate a hard 1dB step during the blend-time.

1

EXT.

MUTE

+SIGNAL

REF

-SIGNAL

1

I

OUT

Time

D97AU634

1dB

0.5dB

-0.5dB

-1dB

Time

D00AU1170

SS Time