[AK4675]
The headphone output is enabled when HPMTN bit is “1” and muted when HPMTN bit is “0”. PTS1-0 bits set the mute
ON/OFF time when MOFF1 bit is “0”. When MOFF1 bit is “1”, the ON/OFF is switched immediately.
When PMHPL and PMHPR bits are “0”, the headphone-amps are powered-down completely. At that time, the HPL and
HPR pins go to VSS3 voltage via the internal pulled-down resistor. The pulled-down resistor is 20Ω (typ) at HPZ bit =
“0”, 25kΩ(typ) at HPZ bit = “1”. The power-up/down time is 16.4ms (typ.) and 26.3ms (max.)when MOFF0 bit is “0”.
When MOFF1 bit is “1”, the power up/down is switched immediately.
PMCP/PMVCM PMHPL/R HPMTN
HPZ
Mode
Power-down & Mute
Power-down
Mute
Normal Operation
HPL/R pins
x
x
1
1
0
0
1
1
x
x
0
1
0
1
0
0
(default)
Pull-down by 20Ω (typ)
Pull-down by 25kΩ (typ)
VSS3A
Normal Operation
Table 78. Headphone Amplifier Mode Setting (x: Don’t’ care)
<Wired OR with External Headphone-Amp>
In case of OSCN bit = “0”, when PMVCMA=PMCP=PMOSC bits are “1” (charge pump circuit is powered-up), the
AK4675 HP-Amp can be connected to the external single supply HP-Amp by “wired OR”. In case of OSCN bit = “1”,
when PMVCMA=PMCP=HPZ bits are “1” (charge pump circuit is powered-up), the AK4675 HP-Amp can be connected
to the external single supply HP-Amp by “wired OR”. The external HP-Amp can output the signal up to ±PVDDA [Vpp]
after the charge pump circuit is powered-up.
HPL pin
AK4675
Headphone
HPR pin
Another
HP-Amp
Figure 82. Wired OR with External HP-Amp
MS0963-E-00
2008/05
- 110 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
