DSD1796DBRG4 datasheet(34/61 Pages) TI1

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DSD1796

SLES101A – DECEMBER 2003 – REVISED NOVEMBER 2006

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Application for Interfacing With an External Digital Filter

For some applications, it may be desirable to use an external digital filter to perform the interpolation function, as it can

provide improved stop-band attenuation when compared to the internal digital filter of the DSD1796.

The DSD1796 supports several external digital filters, including:

D Texas Instruments DF1704 and DF1706

D Pacific Microsonics PMD200 HDCD filter/decoder IC

D Programmable digital signal processors

The external digital filter application mode is accessed by programming the following bit in the corresponding control

D DFTH = 1 (register 20)

The pins used to provide the serial interface for the external digital filter are shown in the connection diagram of Figure 35.

The word clock (WDCK) signal must be operated at 8

× or 4× the desired sampling frequency, fS.

Pin Assignment When Using the External Digital Filter Interface

D PLRCK (pin 4): WDCK as word clock input

D PBCK (pin 6): BCK as bit clock for audio data

D PDATA (pin 5): DATA as monaural audio data input when the DFMS bit is not set to 1

D DSDL (pin 1): DATAL as L-channel audio data input when the DFMS bit is set to 1

D DSDR (pin 2): DATAR as R-channel audio data input when the DFMS bit is set to 1

DSD1796DBRG4 Datasheet(PDF) 34 Page - Texas Instruments