AK4618 Datasheet, PDF (45/60 Pages) Asahi Kasei Microsystems – 192kHz 24-bit 6ch/12ch Audio CODEC with Microphone Interface

[AK4618]
■ DAC Partial Power-Down Function
All of the DACs can be powered-down individually by PMDA6-1 bits. The analog section and the digital section of the
DAC are placed in power-down mode when the PMDA6-1 bits = “0”. The analog output of the powered-down channels,
which are set by PMDA6-1 bits, go to Hi-Z. Some click noise occurs in both set-up and release of power-down. Mute the
analog output externally or set PMDA6-1 bits when PMDAC bit = “0” or RSTN bit = “0”, if click noise aversely affects
system performance. Figure 39 shows the sequence of the power-down and the power-up by PMDA6-1 bits.
PMDA6-1 bit
Power Down Channel
4~5/fs (4)
DAC Digital
Internal State
Normal Operation
DAC Analog
Internal State
Normal Operation
2~3/fs (5)
4~5/fs (4)
2~3/fs (5)
Power-down
Normal Operation
Power-down
Normal Operation
516/fs (6)
516/fs (6)
Power-down _{Init Cycle} Normal Operation Power-down _{Init Cycle} Normal Operation
DAC In
(Digital)
DAC Out
(Analog)
(1)
GD
(3) ₍₂₎
“0”data
(3)
(3) ₍₂₎
GD
(3)
Normal Operation Channel
DAC In
(Digital)
“0”data
GD
GD
DAC Out
(Analog)
Notes:
(1) Analog outputs corresponding to the digital inputs have group delay (GD).
(2) Analog output of the DAC is powered down by PMDA6-1 = “0” and goes to Hi-Z.
(3) Click noise occurs in 45/fs after PMDA6-1 bits are set to “0”, and it occurs in 518519/fs after PMDA6-1 bits are
set to “1”.
(4) The DACs will be powered-down 4~5fs after PMDA6-1 bits = “0”
(5) The initialization stars 2~3fs after PMDA6-1 bits are set to “1”.
(6) The analog parts of DACs are initialized after exiting power down mode.
Figure 39. DAC Partial Power-down Example
015000617-E-00
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2015/01