[AK4675]
■ HP/SPK-Amp Block Power-Up/Down Sequence
1) HP-Amp
Power Supply
(1)
PDNA pin
(2)
PMVCMA bit
PMOSC bit
PMMHL/R bit
MCKIA Input
(3)
Don’t care
Don’t care
PMCP bit
PVEE pin
(4)
0V
PVEE
0V
≥ 0s
(11)
PMV1 bit
(5)
Input Volume
Output State
Hi-Z
VCOMA
Hi-Z
PMHPL/R bits
(6)
HPMTN bit
0V
Normal
MUTE
(7)
MUTE
(9)
0V
HPL/HPR pins
(10)
(8)
Figure 87. HP-Amp Power-up/down Sequence Example
(1) PDNA pin should be changed from “L” to “H” after power up.
“L” time of 150ns or more is needed to reset the AK4675.
The PDNA pin must be held to “L” until all power supply pins are supplied. After that, the PDNA pin should be
set to “H”.
(2) PTS1-0, MOFF, HPGA4-0, OSCN, MSEL bits should be set during this period.
(3) In case of OSCN bit = “0”, the external clock (MCKIA pin) is not needed.
In case of OSCN bit = “1”, the external clock (MCKIA pin) is needed.
(4) Power-up of Charge Pump, VCOMA and HP-Amp Mixer & Selector (and the internal clock oscillator in case of
OSCN bit = “0”): PMCP = PMMHL = PMMHR = PMOSC = PMVCMA bits = “0” Æ “1”
The PVEE pin becomes PVEE voltage within 10ms (max.) at OSCN bit = “1” or within the time in Table 79 at OSCN
bit = “1”.
(5) Power-up of input volume: PMV1 bit = “0” Æ “1”
Input volume setting (L1V3-0, R1V3-0 bits)
Input path setting (HPLL1, HPLR1, HPRR1, HPRL1 bits)
Input volume block is powered-up within 26.3ms (max.) at OSCN bit = “0” or within the time in Table 75 at
OSCN bit = “1”. Input path and volume can be set when input volume block is powered up.
(6) If PMCP and PMHPL/R bits are set to “1” at the same time or PMHPL/R bits are set to “1” during the power-up time
of the Charge Pump circuit, Headphone-Amp is powered-up after the Charge Pump circuit is powered-up.
(7) Headphone-Amp power-up: PMHPL/R bits = “0” Æ “1”
Headphone-Amp is in the mute state and outputs the DC offset. Headphone-Amp power-up time depends on the
setting of OSCN bit. When OSCN bit = “0”, it is 26.3ms (max.) When OSCN bit = “1”, refer to Table 81.
(8) Headphone-Amp mute release: HPMTN bit = “0” Æ “1”
Headphone-Amp goes to the normal operation after the transition time. Headphone-Amp mute release time
depends on the setting of PTS1-0 and MOFF1 bits.
(9) Headphone-Amp mute: HPMTN bit = “1” Æ “0”
MS0963-E-00
2008/05
- 119 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
