wm9081 Wolfson Microelectronics plc, wm9081 Datasheet - Page 30

• 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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The Class D Speaker Disable sequence is initiated by writing 8115h to Register 38 (26h). This single
operation starts the Control Write Sequencer at Index Address 21 (15h). For typical clocking
configurations, this sequence takes approximately 48ms to run.
3. Lineout Enable Sequence
Lineout Enable - This sequence powers up the lineout, and enables the DAC signal path. The lineout
is discharged initially, and the soft-start VMID circuit is used to suppress pops during power-up.
The Lineout Enable sequence is initiated by writing 812Ah to Register 38 (26h). This single operation
starts the Control Write Sequencer at Index Address 42 (2Ah). For typical clocking configurations,
this sequence takes approximately 550ms to run.
4. Lineout Disable Sequence
Lineout Disable - This sequence powers down the lineout. As part of this sequence, the DAC is
muted and disabled, the Lineout is discharged to AGND and the reference/bias circuits are disabled.
The Lineout disable sequence is initiated by writing 813Fh to Register 38 (26h). This single operation
starts the Control Write Sequencer at Index Address 63 (3Fh). For typical clocking configurations,
this sequence takes approximately 646ms to run.
5. Class AB Speaker Enable Sequence
Class AB Speaker Enable - This sequence powers up the speaker driver in Class AB mode, and
enables the DAC signal path. The soft-start VMID circuit is selected as part of this sequence. On
completion, the Lineout is clamped to VMID.
The Class AB Speaker Enable sequence is initiated by writing 8154h to Register 38 (26h). This
single operation starts the Control Write Sequencer at Index Address 84 (54h). For typical clocking
configurations, this sequence takes approximately 42ms to run.
Note that this sequence is optimized for pop suppression on the Speaker output. For pop
suppression on the Line Output, please refer to sequence 3.
6. Class AB Speaker Disable Sequence
Class AB Speaker Disable - This sequence powers down the Class AB speaker driver. As part of this
sequence, the DAC is muted and disabled, the Lineout is discharged to AGND and the
reference/bias circuits are disabled.
The Class AB Speaker Disable sequence is initiated by writing 8169h to Register 38 (26h). This
single operation starts the Control Write Sequencer at Index Address 105 (69h). For typical clocking
configurations, this sequence takes approximately 49ms to run.
Notes
1.
For details on the Control Write Sequencer default sequences, refer to the application
note WAN_0204 ‘WM9081 Control Write Sequencer default sequences’.
PP, Rev 3.0, April 2009
Pre-Production
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