ADAV4601 System Design Document
Confidential Information
Rev.1 August 2009
Analog Devices
Page 22
0V
Vref
(1.5V)
Discharging Vref
Instantaneously
Vref discharger circuit
0V
Vref
(1.5V)
Discharging Vref
Instantaneously
Vref discharger circuit
Figure 13: Vref Discharger Circuit
34 0005 866F
This register write powers down the Vref buffer. The reference voltage Vref has now been powered down to 0V
which means that the input to every amplifier is already at 0V. Therefore there is no longer any need for the Vref
buffer to be powered up.
34 008D 02A1
This register write enables Vref which effectively connects the output of the Vref buffer to ground and also clamps
the headphone outputs to ground. It is recommended to wait for 1 second after performing this write to ensure
that all residual charge is gone from the Vref capacitor.
34 000B 0000
This write tri-states the headphone outputs which sets the outputs of the headphones to high-impedance.
34 000A 0F81
This write disables the PWM channels. It is recommended to wait for 2 seconds after this write before performing an
additional I
2
C write.
34 0006 0200
34 0005 0000
These register writes power down the headphone amplifier, headphones DACs and all the Auxiliary DACs as well as
putting all DACs in low power mode.
34 0000 0000
This register write powers down the rest of the device. This disables all the digital section on the ADAV46xx as well
as disabling the processor and the PLL.
Содержание ADAV4601
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