WM8974 datasheet(33/63 Pages) WOLFSON

номер детали	WM8974

подробное описание детали	MONO CODEC WITH SPEAKER DRIVER

PDF	63 Pages

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производитель	WOLFSON [Wolfson Microelectronics plc]

домашняя страница	http://www.wolfsonmicro.com

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WM8974

PP Rev 1.1 September 2004

ANALOGUE OUTPUTS

The WM8974 has a single MONO output and two outputs SPKOUTP and SPOUTN for driving a

mono BTL speaker. These analogue output stages are supplied from SPKRVDD and are capable of

driving up to 1.5V rms signals (equivalent to 3V rms into a bridge tied speaker) as shown in Figure

15.

Figure 15 Speaker and Mono Analogue Outputs

The Mono and speaker outputs have output driving stages which can be controlled by the register

bits MONOBOOST and SPKBOOST respectively. Each output stage has a selectable gain boost of

1.5x.

When this boost is enabled the output DC level is also level shifted (from AVDD/2 to

1.5xAVDD/2) to prevent the signal from clipping. A dedicated amplifier, as shown in Figure 15, is

used to perform the DC level shift operation. This buffer must be enabled using the BUFDCOPEN

greater than 1.5xAVDD this boost mode may result in signals clipping. Table 20 summarises the

effect of the SPKRBOOST/MONOBOOST control bits.

WM8974 датащи(PDF) 33 Page - Wolfson Microelectronics plc