TAS5015

SLES017 – SEPTEMBER 2001

9

www.ti.com

functional description (continued)

de-emphasis filter

For audio sources that have been preemphasized, a precision 50

µs/15 µs de-emphasis filter is provided to

support the sampling rates of 44.1 kHz and 48 kHz. Pins DEM_SEL and DEM_EN select the de-emphasis

functions. See Figure 6 for a graph showing the de-emphasis filtering characteristics. See Table 3 for

de-emphasis selection.

0

–10

3.18 (50

µs)

10.6 (15

µs)

f – Frequency – kHz

De-emphasis

Figure 6. De-Emphasis Filter Characteristics

de-emphasis selection

De-emphasis selection is accomplished by using the DEM_SEL and DEM_EN pins. See Table 3 for

de-emphasis selection description.

Table 3. De-Emphasis Selection

DEM_SEL

DEM_EN

DESCRIPTION

0

0

De-emphasis disabled

0

1

De-emphasis enabled for Fs = 44.1 kHz

1

1

De-emphasis enabled for Fs = 48 kHz

1

0

Disallowed state. Do not use.

error status reporting (VALID_L and VALID_R)

The following is a list of the error conditions that will cause the VALID_L and VALID_R pins to be asserted low.

–

No clocks

–

Clock phase errors

When either of the above conditions is met, the VALID_L and VALID_R goes low and the PWM outputs go to

the hard mute state. If the error condition is removed, the TAS5015 is reinitialized and the VALID_L and VALID_R

pins are asserted high.

serial interface formats

The TAS5015 is compatible with eight different serial interfaces. Available interface options are IIS, right

justified, left justified, and DSP frame. Table 4 indicates how these options are selected using the MOD0, MOD1,

and MOD2 pins.