WM8569

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PP Rev 1.1 December 2005

34

SUGGESTED ANALOGUE LOW PASS POST DAC FILTERS

It is recommended that a lowpass filter be applied to the output from each DAC channel for Hi Fi applications. Typically a

second order filter is suitable and provides sufficient attenuation of high frequency components (the unique low order, high

bit count multi-bit sigma delta DAC structure used in WM8569 produces much less high frequency output noise than

normal sigma delta DACs. This filter is typically also used to provide the 2x gain needed to provide the standard 2Vrms

output level from most consumer equipment.

Wolfson Application Note WAN0171 provides details of suitable post-DAC filter circuits.

Figure 32 Recommended Post DAC Filter Circuit