ak4671 AKM Semiconductor, Inc., ak4671 Datasheet - Page 90

• Manufacturer Part Number: ak4671
• Description: Stereo Codec With Mic/rcv/hp-amp
• Manufacturer: AKM Semiconductor, Inc.

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Power supply voltage for the LOUT2/ROUT2 is supplied from the AVDD pin and centered on the 0.5 x AVDD (typ)
voltage. The load resistance is 16 Ω (min). HPG3-0 bits control the output volume
When LOM2 bit = “1”, DAC output signal is output to LOUT2 and ROUT2 pins as (L+R) mono signal.
When LOOPM2 bit = “1”, the MIC-Amp signal is output to LOUT2 and ROUT2 pins as (L+R) mono signal.
When the MUTEN bit is “0”, the common voltage of LOUT2/ROUT2 falls and the outputs (LOUT2 and ROUT2 pins)
change to “L” (VSS1). When the MUTEN bit is “1”, the common voltage rises to VCOM voltage. A capacitor between
the MUTET pin and ground reduces pop noise at power-up. Rise/Fall time constant is in proportional to AVDD voltage
and the capacitor at MUTET pin.
[Example]: A capacitor between the MUTET pin and ground = 1.0 μ F, AVDD=3.3V:
When PMLO2, PMRO2, PMLO2S and PMRO2S bits are “0”, the LOUT2/ROUT2 is powered-down, and the outputs
(LOUT2 and ROUT2 pins) go to “L” (VSS1).
(1) LOUT2/ROUT2 power-up (PMLO2, PMRO2, PMLO2S, PMRO2S bit = “1”). The outputs are still VSS1.
(2) LOUT2/ROUT2 common voltage rises up (MUTEN bit = “1”).
(3) LOUT2/ROUT2 common voltage falls down (MUTEN bit = “0”).
(4) LOUT2/ROUT2 power-down (PMLO2, PMRO2, PMLO2S, PMRO2S bit = “0”). The outputs are VSS1. If the power
MS0666-E-00
Headphone Output (LOUT2/ROUT2 pins)
supply is switched off or LOUT2/ROUT2 is powered-down before the common voltage goes to VSS1, some POP
noise occurs.
PMLO2 bit, PMRO2 bit,
PMLO2S bit, PMRO2S bit
MUTEN bit
LOUT2 pin,
ROUT2 pin
Rise/fall time constant:
Time until the common goes to VSS1 when MUTEN bit = “1”
Figure 72. Power-up/Power-down Timing for LOUT2/ROUT2
τ
= 100ms(typ), 250ms(max)
Table 70. LOUT2/ROUT2 Output Volume
HPG3-0
(1) (2)
DH
CH
BH
AH
2H
1H
0H
:
:
Attenuation
- 90 -
MUTE
− 27dB
− 30dB
+6dB
+3dB
− 3dB
0dB
:
:
(3)
(default)
(4)
“0”: 500ms(max)
(Table
70).
[AK4671]
2007/10