TDA7416 datasheet(11/27 Pages) STMICROELECTRONICS

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TDA7416

1.4 SoftMute

The digitally controlled SoftMute stage allows muting/demuting the signal with a I2C-bus programmable

slope. The mute process can either be activated by the SoftMute pin or by the I2C-bus. This slope is real-

ized in a special S-shaped curve to mute slow in the critical regions (see Figure 5).

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

of de-muting.

Figure 5. Soft Mute-Timing

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

1.5 SoftStep Volume and Speaker

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

clicks could either be a DC-Offset before the speaker-stage or the sudden change of the envelope of the

audio signal. 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 6. SoftStep-Timing for Volume

Note: For steps more than 0.5dB (Volume) or 1dB (Speaker) the SoftStep mode should be deactivated because it could generate a hard 1dB

step during blending.

1dB

0.5dB

-0.5dB

-1dB

SS Time

TDA7416 Datasheet(PDF) 11 Page - STMicroelectronics