AK4373 Datasheet, PDF (56/98 Pages) Asahi Kasei Microsystems – Low Power Stereo DAC with HP/SPK-Amp

[AK4373]
■ De-emphasis Filter
The AK4373 includes the digital de-emphasis filter (tc = 50/15μs) by IIR filter. Setting the DEM1-0 bits enables the
de-emphasis filter (Table 31).
DEM1
0
0
1
1
DEM0
Mode
0
44.1kHz
1
OFF
0
48kHz
1
32kHz
Table 31. De-emphasis Control
(default)
■ Digital Output Volume
The AK4373 has a digital output volume (256 levels, 0.5dB step, Mute). The volume can be set by the DVL7-0 and
DVR7-0 bits. The volume is included in front of a DAC block. The input data of DAC is changed from +12 to –115dB or
MUTE. When the DVOLC bit = “1”, the DVL7-0 bits control both Lch and Rch attenuation levels. When the DVOLC bit
= “0”, the DVL7-0 bits control Lch level and DVR7-0 bits control Rch level. This volume has a soft transition function.
The DVTM bit sets the transition time between set values of DVL/R7-0 bits as either 1061/fs or 256/fs (Table 33). When
DVTM bit = “0”, a soft transition between the set values occurs (1062 levels). It takes 1061/fs (=24ms@fs=44.1kHz)
from 00H (+12dB) to FFH (MUTE).
DVL/R7-0
Gain
00H
+12.0dB
01H
+11.5dB
02H
+11.0dB
:
:
18H
0dB
(default)
:
:
FDH
−114.5dB
FEH
−115.0dB
FFH
MUTE (−∞)
Table 32. Digital Volume Code Table
DVTM bit
0
1
Transition time between DVL/R7-0 bits = 00H and FFH
Setting
fs=8kHz
fs=44.1kHz
1061/fs
133ms
24ms
256/fs
32ms
6ms
Table 33. Transition Time Setting of Digital Output Volume
(default)
MS0991-E-00
- 56 -
2008/09