DS4201

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102099

POWER MANAGEMENT

The power management features of the DS4201 are used to control device and external circuit power con-

sumption whenever a USB suspend state is entered; the suspend power mode (SPM) input and suspend

output (SUSO\) signals are used for this control.

SUSPEND POWER MODE

The DS4201 supports two modes of operation when the USB enters a suspend state; the suspend power

mode input signal (SPM) is used to select which of the two modes the device will enter upon suspend.

When the suspend state is entered, the SPM input level is used to selectively shut down specific DS4201

circuitry. Power consumption during the USB suspended state for the two suspend power modes and

various input voltage conditions are listed in the DC Characteristics Table and are summarized in the

following table and paragraphs:

SUSPEND POWER STATES Table 4

BUS STATE

SPM

POWER CONSUMPTION

Active

X

Active

Suspended

1

Reduced from active

Suspended

0

Minimum

When SPM=1 and the USB enters a suspend state, the DS4201 DAC and oscillators are powered down

and digital circuitry enters a low power static state. All other analog circuitry remains powered so that the

signal paths for the AUX and MIC inputs are active.

When SPM=0 and the USB enters a suspend state, power consumption is minimized. For this state\mode,

all analog circuitry and oscillators are powered down and digital circuitry enters a low power static state.

NOTE:

For this state\mode the analog circuitry in the AUX and MIC paths are powered down and analog audio

playback over the AUX and MIC channels will be turned off until the USB returns to an active state.

Therefore it is recommended that the AUX and MIC inputs not be made available for analog input

playback in an application where SPM=0.

Suspend Output

signal could be used stand–alone or combined with other external signals to power down circuitry

external to the DS4201, such as amplifiers and power sources, to manage audio system power

external pull–up to a positive supply no greater than 6.0V.

OSCILLATORS

The DS4201 requires two clock sources to operate: 12.0 MHz and 12.288 MHz. Crystals or CMOS

crystal oscillators may be used to provide the clock sources.