ak4628 AKM Semiconductor, Inc., ak4628 Datasheet - Page 28

• Manufacturer Part Number: ak4628
• Description: High Performance Multi Channel Audio Codec
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
T DAC partial Power-Down Function
All DACs of AK4628 can be powered-down individually by PD1-4 bits. The analog part of DAC is in power-down by
PD1-4 bits =”1”, however, the digital part is not in power-down by it. Even if all DACs were set in power-down by the
partial power-down bits, the digital part continue to function. The analog output of the channel which is set in
power-down by PD1-4 bits is fixed to the voltage of VCOM. And though DZF detection is being done, the result of DZF
detection stops reflecting to DZF1-2 pins. Because some click noise occurs in both set-up and release of power-down,
either the analog output should be muted externally or PD1-4 bits should be set up when it is in PWDAN bit =”0” or
RSTN bit =”0”, if the click noise influences system application. Figure 16 shows the sequence of the power-down and the
power-up by PD1-4 bits.
Notes:
MS0211-E-02
(3) Immediately after PD1-4 bits are changed, some click noise occurs at the output of the channel changed by the own
(1) Digital output corresponding to analog input and analog output corresponding to digital input have the group delay
(2) Analog output of the DAC powered down by PD1-4 =”1” is fixed to the voltage of VCOM.
(4) Though DZF detection is being done at a certain channel which set up PD1-4 =”1”, the result of DZF detection
(5) DZF detection of the DAC which is set up by the power-down setting is ignored, and DZF1-2 pins become ”H”.
(6) When the power-down function is set up and the channel has input signal, even if the partial power-down function
PD bits.
(GD).
stops reflecting to DZF1-2 pins.
is set up, DZF1-2 bits do not become ”H”.
Normal Operation Channel
Clock In
MCLK,LRCK,SCLK
DZF1/DZF2
DAC Analog
Internal State
DAC In
DAC Out
DZF Detect
Internal State
DAC In
DAC Out
DZF Detect
Internal State
Power Down Channel
DAC Digital
Internal State
PD1-4 bit
(Digital)
(Analog)
(Digital)
(Analog)
Normal Operation
8192/fs
GD
Figure 16. DAC partial power-down example
“0”data
8192/fs
GD
(5)
(1)
Power-down
(3)
(2)
(4)
(3)
Normal Operation
“0”data
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Normal Operation
GD
(3)
Power-down
(6)
(4)
(2)
(3)
Normal Operation
Normal Operation
GD
[AK4628]
2004/03