AK4372 Datasheet, PDF (26/62 Pages) Asahi Kasei Microsystems – DAC with built-in PLL & HP-AMP

[AK4372]
■ Digital Attenuator
The AK4372 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 17). At
DATTC bit = “1”, ATTL7-0 bits control both channel’s attenuation levels. At DATTC bit = “0”, ATTL7-0 bits control
the left channel level and ATTR7-0 bits control the right channel level.
ATTL7-0
ATTR7-0
Attenuation
FFH
0dB
FEH
−0.5dB
FDH
−1.0dB
FCH
−1.5dB
:
:
02H
−126.5dB
01H
−127.0dB
00H
MUTE (−∞) (default)
Table 17. Digital Volume ATT values
The ATS bit sets the transition time between set values of ATT7-0 bits as either 1061/fs or 7424/fs (Table 18). When the
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. The digital attenuator is independent of the soft mute function.
ATS
ATT speed
0dB to MUTE
1 step
0
1061/fs
4/fs
(default)
1
7424/fs
29/fs
Table 18. Transition time between set values of ATT7-0 bits
MS0684-E-02
- 26 -
2008/12