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[AK4458]
014011794-E-01
2015/08
- 59 -
■
Power Off and Reset Functions
RSTN
PW1/2/3/4
DAC1/2/3/4
Register Digital
Analog Output
DAC1
DAC2
DAC3
DAC4
1
0000
OFF/OFF/OFF/OFF
Hold
Off
Hi-Z
Hi-Z
Hi-Z
Hi-Z
1
1000
ON/OFF/OFF/OFF
Hold
On
normal
Hi-Z
Hi-Z
Hi-Z
1
0100
OFF/ON/OFF/OFF
Hold
On
Hi-Z
normal
Hi-Z
Hi-Z
1
0010
OFF/OFF/ON/OFF
Hold
On
Hi-Z
Hi-Z
normal
Hi-Z
1
0001
OFF/OFF/OFF/ON
Hold
On
Hi-Z
Hi-Z
Hi-Z
normal
1
1111
ON/ON/ON/ON
Hold
On
normal
normal
normal
normal
0
0000
OFF /OFF/OFF/OFF
Hold
Off
Hi-Z
Hi-Z
Hi-Z
Hi-Z
0
1000
ON/OFF/OFF/OFF
Hold
Off
VREFH/2
Hi-Z
Hi-Z
Hi-Z
0
0100
OFF/ON/OFF/OFF
Hold
Off
Hi-Z
VREFH/2
Hi-Z
Hi-Z
0
0010
OFF/OFF/ON/OFF
Hold
Off
Hi-Z
Hi-Z
VREFH/2
Hi-Z
0
0001
OFF/OFF/OFF/ON
Hold
Off
Hi-Z
Hi-Z
Hi-Z
VREFH/2
0
1111
ON/ON/ON/ON
Hold
Off
VREFH/2 VREFH/2 VREFH/2
VREFH/2
Table 29. Power Off and Reset Function
(1) Power OFF Function 1 (PW1-4 bits)
All DAC1-4 can be powered down immediately by setting PW1-4 bits to “0000”. In this time, all circuits
except registers are powered down and the analog output goes to floating state (Hi-z).
Figure 59
shows a timing
example of power-on and power-down.
Normal Operation
Internal
State
PW1-4 bit
Power-off
Normal Operation
GD
GD
“0” data
D/A Out
(Analog)
D/A In
(Digital)
Clock In
MCLK, BICK, LRCK
(1)
(3)
(5)
DZF
External
MUTE
(4)
(3)
(1)
Mute ON
(2)
Don
’t care
Notes:
(1) The analog output corresponding to digital input has group delay (GD).
(2) Analog outputs are floating (Hi-Z) in power down mode.
(3) Small pop noise occurs at the edges(“
”) of the internal timing of PW1-4 bits. This noise is output
even if “0” data is input.
(4) Mute the analog output externally if click noise (3) adversely affect system performance.
(5) The DZF pin outputs “L”, in power down mode (PW1-4 bits = “0000”).
Figure 59. Power-off/on Sequence Example 1