wm9081 Wolfson Microelectronics plc, wm9081 Datasheet - Page 78

• Manufacturer Part Number: wm9081
• Description: Mono Dac With 2.6w Class Ab/d Speaker Driver, Dynamic Range Controller And Retune Mobile Parametric Equalizer
• Manufacturer: Wolfson Microelectronics plc

WM9081
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Table 47 Soft Start Control
The master bias current is configurable using the BIAS_LVL register. This enables power
consumption to be reduced under selected operating conditions. The normal bias current is
recommended for all active operating modes.
If a low power standby configuration is required, (for example, if the WM9081 is powered up and
configured, but is not actually generating an audio output), then the master bias may be switched to a
standby level, enabling further reduction in power consumption. The standby bias level is enabled
using STBY_BIAS_ENA and is configured using STBY_BIAS_LVL, as described in Table 48.
Table 48 Master Bias Level Control
R4 (04h)
VMID
Control
R5 (05h)
Bias Control
1
R5 (05h)
Bias Control
1
REGISTER
REGISTER
ADDRESS
ADDRESS
BIT
BIT
3:2
3
0
6
0
5
4
VMID_RAMP
VMID_FAST_ST
BIAS_SRC
STARTUP_BIAS_
ENA
STBY_BIAS_LVL
STBY_BIAS_ENA
BIAS_LVL [1:0]
LABEL
LABEL
DEFAULT
DEFAULT
10
0
1
1
0
1
0
VMID Soft Start control
0 = Normal
1 = Soft Start
VMID Slew Rate control
0 = Slow
1 = Fast
Selects the bias current source
0 = Normal bias
1 = Start-Up bias
Enables the Start-Up bias current
generator
0 = Disabled
1 = Enabled
Standby bias current select
0 = Normal bias x 0.5
1 = Normal bias x 0.25
Selects the Standby bias level
0 = Disabled (Bias set by BIAS_LVL)
1 = Enabled (Bias set by
STBY_BIAS_LVL)
Master bias current select
00 = Normal bias x 0.5
01 = Normal bias x 0.75
10 = Normal bias
11 = Normal bias x 1.5
DESCRIPTION
DESCRIPTION
PP, Rev 3.0, April 2009
Pre-Production
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