AK4646EZ Datasheet, PDF (44/78 Pages) Asahi Kasei Microsystems – Stereo CODEC with MIC/SPK-AMP

[AK4646EZ]
■ Output Digital Volume (Manual Mode)
The ALC block becomes output digital volume (manual mode) by setting ALC2 bit to “0” when both Lch and Rch of
ADC are powered-down (PMADL = PMADR bits = “1”) or DAFIL bit is “1”. The output digital volume gain is set by
the OVL7-0 bit and the OVR7-0 bit (Table 35). When the OVOLC bit = “1”, the OVL7-0 bits control both Lch and Rch
volume levels. When the OVOLC bit = “0”, the OVL7-0 bits control Lch level and the OVR7-0 bits control Rch level.
The OVOL value is changed at zero crossing or timeout. The zero crossing timeout period is set by ZTM1-0 bits.
OVL7-0 bits
OVR7-0 bits
GAIN(0dB)
Step
F1H
+36.0
F0H
+35.625
EFH
+35.25
:
:
0.375dB
92H
+0.375
91H
0.0
90H
-0.375
:
:
2H
-53.625
1H
-54.0
0H
MUTE
Table 35. Output Digital Volume Setting
(default)
When writing to the OVL7-0 bits and OVR7-0 bit continuously, the control register should be written by an interval more
than zero crossing timeout. If not, the zero crossing counter is reset at each time and the volume will not be changed.
However, it could be ignored when writing the same register value as the last time. In this case, zero crossing counter will
not be reset, so that it could be written by an interval less than zero crossing timeout.
■ Output Digital Volume 2
AK4646 has 4 steps output volume in addition to the volume setting by DATT1-0 bits. Lch and Rch have the same
volume values, which are set by DATT1-0 bits as shown in Table 36.
DATT1-0bits GAIN(0dB)
Step
0H
0.0
1H
-6.0
6.0dB
2H
-12.0
3H
-18.1
Table 36. Output Digital Volume2 Setting
(default)
■ De-emphasis Filter
The AK4646 includes the digital de-emphasis filter (tc = 50/15μs) which corresponds 3 kinds frequency (32kHz, 44kHz,
48kHz) by IIR filter. Setting the DEM1-0 bits enables the de-emphasis filter (Table 37).
DEM1
0
0
1
1
DEM0
Mode
0
44.1kHz
1
OFF
0
48kHz
1
32kHz
Table 37. De-emphasis Control
(default)
MS0630-E-00
- 44 -
2007/06