AK4648 Datasheet, PDF (77/119 Pages) Asahi Kasei Microsystems – Stereo CODEC with MIC/HP/SPK-AMP

[AK4648]
AVDD
3.3V
HVDD
3.6V
4.5V
SPKG2-0 bits
000
001
010
011
000
001
010
011
SPK-Amp Output (DAC Input = 0dBFS)
ALC bit = “0”
ALC bit = “1”
(LMTH1-0 bits = “00”; -2.5dBFS)
3.30Vpp
3.11Vpp
4.15Vpp
3.92Vpp
5.2Vpp (Note 64)
5.2Vpp (Note 64)
5.2Vpp (Note 64)
5.2Vpp (Note 64)
3.30Vpp
3.11Vpp
4.15Vpp
3.92Vpp
6.75Vpp
6.37Vpp
7.0Vpp (Note 64)
7.0Vpp (Note 64)
Note 64. The output level is calculated assuming that output signal is not clipped. In actual case, output signal may be
clipped when DAC outputs 0dBFS signal. DAC output level should be set to lower level by setting digital
volume so that Speaker-Amp output level is 5.2Vpp (HVDD=3.6V) or 7.0Vpp (HVDD=4.5V) or less and output
signal is not clipped.
Table 66. SPK-Amp Output Level
<ALC Operation Example of Speaker Playback>
Register Name Comment
fs=44.1kHz
Data
Operation
LMTH1-0
Limiter detection Level
00
−2.5dBFS
ZELMN
Limiter zero crossing detection
0
Enable
ZTM1-0
Zero crossing timeout period
10
11.6ms
Recovery waiting period
WTM2-0
*WTM2-0 bits should be the same data 011
23.2ms
as ZTM1-0 bits
REF7-0
Maximum gain at recovery operation C1H
+18dB
IVL7-0,
IVR7-0
Gain of IVOL
91H
0dB
LMAT1-0
Limiter ATT step
00
1 step
RGAIN1-0
Recovery GAIN step
00
1 step
ALC
ALC enable
1
Enable
Table 67. ALC Opeation Example of Speaker Playback
MS0625-E-01
- 77 -
2007/06