Production Data

WM8782

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PD, April 2010, Rev 4.7

17

DIGITAL FILTER CHARACTERISTICS

The WM8782 digital filter characteristics scale with sample rate.

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

ADC Sample Rate (Single Rate – 48Hz typically)

Passband

+/- 0.01dB

0

0.4535fs

-6dB

0.4892fs

Passband Ripple

+/- 0.01

dB

Stopband

0.5465fs

Stopband Attenuation

f > 0.5465fs

-65

dB

Group Delay

22

fs

ADC Sample Rate (Dual Rate – 96kHz typically)

Passband

+/- 0.01dB

0

0.4535fs

-6dB

0.4892fs

Passband Ripple

+/- 0.01

dB

Stopband

0.5465fs

Stopband Attenuation

f > 0.5465fs

-65

dB

Group Delay

22

fs

Table 10 Digital Filter Characteristics

ADC FILTER RESPONSES

-80

-60

-40

-20

0

0

0.5

1

1.5

2

2.5

3

Frequency (Fs)

-0.02

-0.015

-0.01

-0.005

0

0.005

0.01

0.015

0.02

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

Frequency (Fs)

Figure 13 Digital Filter Frequency Response

Figure 14 ADC Digital Filter Ripple