TAS3001CPWR datasheet(12/56 Pages) TI

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1−6

1.8

Bass and Treble Controls

The TAS3001 has bass and treble controls that can be adjusted dynamically. These controls can be adjusted

throughout their entire range of 18 dB to –18 dB without experiencing any pops, clicks, or other audible artifacts. This

permits the user to have a listening experience much like what is experienced when adjusting high-quality analog

controls.

Figure 1−7 shows the response for the bass and treble filters plotted at 3-dB intervals for 44.1-kHz sample-rate data.

−20

−15

−10

−5

f − Frequency − Hz

ATTENUATION

FREQUENCY

100

10k

Figure 1−7. Bass and Treble Filters

1.9

Soft Volume and True Soft Mute

The TAS3001 contains a Texas Instruments proprietary soft volume update. This allows a smooth and

pleasant-sounding change from one volume level to another over the entire range of volume (18 dB to mute). The

volume is adjustable by downloading a 4.20 gain coefficient through the I2C interface.

Mute is implemented by loading all zeros in the volume control register. This causes the volume to ramp down over

2048 samples to a final output of zero (−

∞ dB).

1.10 Reliability and Flexibility of Digital Filtering

Digital filtering provides outstanding consistency, reliability, and flexibility. Once a digital filter is designed and tested

in the system, it continues to perform in the same manner without change. Because digital filters are computed, their

performance is exceedingly consistent and does not change due to variations in component matching, tolerances,

environmental conditions, aging, or the effects of moisture and dust. Analog filters, however, are affected by all of

these. The performance of analog filters can be improved, in part, by using high-quality precision components but

this comes with a higher comparable cost.

One of the greatest strengths of a digital filter is its flexibility. Each filter is completely specified by five 24-bit

coefficients. By modifying the value of one or more of the filter coefficients, both the filter value and filter type are

changed. In a system, these modifications produce different crossover curves, different equalization curves, different

sound effects (by changing the relative phase of the left and right loudspeakers) or different user graphical

equalization settings.

TAS3001CPWR Datasheet(PDF) 12 Page - Texas Instruments