WM8974 datasheet(37/63 Pages) WOLFSON

No. de pieza	WM8974

Descripción Electrónicos	MONO CODEC WITH SPEAKER DRIVER

PDF	63 Pages

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Fabricante Electrónico	WOLFSON [Wolfson Microelectronics plc]

Página de inicio	http://www.wolfsonmicro.com

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WM8974

PP Rev 1.1 September 2004

ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

R49

VROI

VREF (AVDD/2 or 1.5xAVDD/2) to

analogue output resistance

0: approx 1k

Ω

1: approx 30 k

Ω

Table 26 Disabled Outputs to VREF Resistance

A dedicated buffer is available for tieing off unused analogue I/O pins as shown in Figure 16. This

buffer can be enabled using the BUFIOEN register bit.

If the SPKBOOST or MONOBOOST bits are set then the relevant outputs will be tied to the output of

the DC level shift buffer at 1.5xAVDD/2 when disabled.

Table 27 summarises the tie-off options for the speaker and mono output pins.

Figure 16 Unused Input/Output Pin Tie-off Buffers

MONOEN/

SPKN/PEN

MONOBOOST/

SPKRBOOST

VROI

OUTPUT CONFIGURATION

1kΩ tieoff to AVDD/2

30kΩ tieoff to AVDD/2

1kΩ tieoff to 1.5xAVDD/2

30kΩ tieoff to 1.5xAVDD/2

Output enabled (DC level=AVDD/2)

Output enabled (DC level=1.5xAVDD/2)

Table 27 Unused Output Pin Tie-off Options

WM8974 Datasheet(PDF) 37 Page - Wolfson Microelectronics plc