WM8728

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WOLFSON MICROELECTRONICS LTD

PP Rev 1.2 April 2001

22

INFINITE ZERO DETECTION

Setting the IZD register bit determines whether the device is automuted when a sequence of more

than 1024 ZEROS is detected.

REGISTER ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

0011

Interface Control

8IZD

0

Infinite ZERO detection circuit

control and automute control

0: Infinite ZERO detect disabled

1: Infinite ZERO detect enabled

Table 20 IZD Control

DIGITAL FILTER CHARACTERISTICS

PARAMETER

SYMBOL

TEST CONDITIONS

MIN

TYP

MAX

UNIT

Passband Edge

-3dB

0.487fs

Passband Ripple

f < 0.444fs

±0.05

dB

Stopband Attenuation

f > 0.555fs

-60

dB

Table 21 Digital Filter Characteristics

DAC FILTER RESPONSES

-120

-100

-80

-60

-40

-20

0

0

0.5

1

1.5

2

2.5

3

Frequency (Fs)

Figure 16 DAC Digital Filter Frequency Response

-44.1, 48 and 96kHz

-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

Frequency (Fs)

Figure 17 DAC Digital Filter Ripple

-44.1, 48 and 96kHz

-80

-60

-40

-20

0

0

0.2

0.4

0.6

0.8

1

Frequency (Fs)

Figure 18 DAC Digital Filter Frequency Response

-192kHz

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

Frequency (Fs)

Figure 19 DAC Digital Filter Ripple

-192kHz