WM8741 datasheet(41/63 Pages) WOLFSON

номер детали	WM8741

подробное описание детали	24-bit 192kHz DAC with Advanced Digital Filtering

PDF	63 Pages

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производитель	WOLFSON [Wolfson Microelectronics plc]

домашняя страница	http://www.wolfsonmicro.com

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WM8741

PP Rev 1.3 October 2007

ZERO FLAG

In hardware control mode the ZFLAG pin asserts when 1024 consecutive zero samples are applied

to the left and right channels of the WM8741 when in PCM mode. In DSD mode, the ZFLAG has no

function.

In hardware mode there is no access to the infinite zero detect and so there is no automute function.

If this functionality is required, software mode must be used. Figure 27 shows the MUTEB and

ZFLAG configuration.

Figure 27 Hardware Control Mode MUTEB & ZFLAG Configuration

DE-EMPHASIS CONTROL AND ANTI-CLIPPING MODE

In hardware control mode, de-emphasis is supported at a sampling rate of 44.1kHz. De-emphasis is

supported at 32kHz and 48kHz sampling rates in software control mode.

Audio material is regularly recorded up to 0dB level and heavily compressed. This causes clipping

and distortion when the digital media is applied to a DAC. In order to prevent this in the WM8741, an

anti-clipping mode is provided, which attenuates the digital signal by 2dB as it is processed through

the digital filters.

Under hardware control de-emphasis and the anti-clipping mode are only available when using PCM

mode.

NAME

DESCRIPTION

SDIN/

DEEMPH

Deemphasis Control

0 = De-emphasis off

1 = 44.1kHz de-emphasis on

Z = Digital filter anti-clipping mode

Table 47 DEEMPH Hardware Control Pin Function

WM8741 датащи(PDF) 41 Page - Wolfson Microelectronics plc