wm8594seft-v Wolfson Microelectronics plc, wm8594seft-v Datasheet - Page 48

• Manufacturer Part Number: wm8594seft-v
• Description: 24-bit 192khz 2vrms Multi-channel Codec
• Manufacturer: Wolfson Microelectronics plc

WM8594
EMERGENCY POWER DOWN
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In the event of sudden power failure in a system, or any other emergency condition, the /PWDN pin
may be used to power the device down from any state in a controlled manner. This may be useful in
a system where there is no guarantee the power supplies will be available long enough to complete
the recommended power down sequence using software writes.
When the /PWDN is pulled low, the device will mute and then power down the outputs quietly. If the
WM8593 is still receiving clocks, the outputs will be softmuted. If the clocks have stopped, the
outputs will be muted immediately. Figure 24 shows the operation of /PWDN and the effect on the
outputs of the device:
Figure 24 /PWDN Operation
It is expected that power is removed from the device before the device is used again, forcing the
device to be reset via the POR. If this is not the case, the device must be manually reset by the
customer (either by a software or hardware reset) once the /PWDN is pulled high again.
PD Rev 4.1 July 2008
Production Data
48