ak4367 AKM Semiconductor, Inc., ak4367 Datasheet - Page 16

• Manufacturer Part Number: ak4367
• Description: Low Power 24-bit 2ch Dac With Hp-amp & Output Mixer
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
The AK4367 has a channel-independent digital attenuator (256 levels, 0.5dB step). This digital attenuator is placed before
the D/A converter. ATTL/R7-0 bits set the attenuation level (0dB to −127dB or MUTE) for each channel (Table 4). At
DATTC bit = “1”, ATTL7-0 bits control both Lch and Rch attenuation levels. At DATTC bit = “0”, ATTL7-0 bits control
the Lch level and ATTR7-0 bits control the Rch level. When HPM bit = “1”, (L+R)/2 summation is done after volume
control.
The ATS bit sets the transition time between set values of ATT7-0 bits as either 1061/fs or 7424/fs (Table 5). When ATS
bit = “0”, a soft transition between the set values occurs(1062 levels). It takes 1061/fs (24ms@fs=44.1kHz) from
FFH(0dB) to 00H(MUTE). The ATTs are 00H when the PMDAC bit is “0”. When the PMDAC returns to “1”, the ATTs
fade to their current value. Digital attenuator is independent of the soft mute function.
MOUT volume is controlled by ATTM3-0 bits when MMUTE bit = “0” (Table 6). Pop noise occurs when ATT3-0 bits
are changed.
MS0247-E-02
Digital Attenuator
Table 5. Transition time between set values of ATT7-0 bits
MMUTE
ATS
0
1
0
1
ATTR7-0
ATTL7-0
Table 6. MOUT Volume ATT values
Table 4. Digital Volume ATT values
FDH
FCH
FFH
FEH
02H
01H
00H
0dB to MUTE
:
:
1061/fs
7424/fs
ATTM3-0
0DH
0FH
0EH
0CH
01H
00H
x
:
:
ATT speed
MUTE (−∞)
Attenuation
−126.5dB
−127.0dB
- 16 -
−0.5dB
−1.0dB
−1.5dB
0dB
:
:
1 step
Attenuation
29/fs
4/fs
MUTE
−28dB
−30dB
−2dB
−4dB
−6dB
0dB
:
:
Default
Default
Default
[AK4367]
2005/10