wm8974gefl-v Wolfson Microelectronics plc, wm8974gefl-v Datasheet - Page 46

• Manufacturer Part Number: wm8974gefl-v
• Description: Mono Codec With Speaker Driver
• Manufacturer: Wolfson Microelectronics plc

WM8974
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Table 43 Disabled Outputs to VREF Resistance
Table 44 Unused Output Pin Tie-off Options
A dedicated buffer is available for tying off unused analogue I/O pins as shown in Figure 21. 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 44 summarises the tie-off options for the speaker and mono output pins.
Figure 21 Unused Input/Output Pin Tie-off Buffers
R49
SPKN/PEN
MONOEN/
REGISTER
ADDRESS
0
0
0
0
1
1
MONOBOOST/
SPKBOOST
0
BIT
0
0
1
1
0
1
VROI
LABEL
VROI
X
X
0
1
0
1
0
DEFAULT
1k Ω tieoff to AVDD/2
30k Ω tieoff to AVDD/2
1k Ω tieoff to 1.5xAVDD/2
30k Ω tieoff to 1.5xAVDD/2
Output enabled (DC level=AVDD/2)
Output enabled (DC level=1.5xAVDD/2)
OUTPUT CONFIGURATION
VREF (AVDD/2 or 1.5xAVDD/2) to analogue
output resistance
0: approx 1kΩ
1: approx 30 kΩ
PD, Rev 4.5, September 2008
DESCRIPTION
Production Data
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