AK4955 Datasheet, PDF (64/117 Pages) Asahi Kasei Microsystems – 24bit Stereo CODEC with MIC/SPK/Cap-less VIDEO-AMP/ LDO & DSP

[AK4955]
■ Speaker Output
The DAC output signal is input to the speaker amplifier as mono signal [(L+R)/2]. The speaker amplifier has mono output
as it is BLT (Bridged Transless) capable. The gain and output level are set by SPKG1-0 bits. The output level is depends
on AVDD and SPKG1-0 bits setting.
SPKG1-0 bits
00
01
10
11
Gain
ALC bit = “0”
ALC bit = “1”
+6.1dB
+8.1dB
+8.1dB
+10.1dB
+10.1dB
+12.1dB
+12.1dB
+14.1dB
Table 60. SPK-Amp Gain
(default)
SVDD
3.3V
4.8V
SPKG1-0 bits
00
01
10
11
00
01
10
11
SPK-Amp Output (DAC Input =0dBFS)
ALC bit = “0”
ALC bit = “1”
(LMTH1-0 bits = “00”)
3.37Vpp
3.17Vpp
4.23Vpp (Note 49)
4.00Vpp
5.33Vpp (Note 49)
5.04Vpp (Note 49)
6.71Vpp (Note 49)
6.33Vpp (Note 49)
3.37Vpp
3.17Vpp
4.23Vpp
4.00Vpp
5.33Vpp
5.04Vpp
6.71Vpp (Note 49)
6.33Vpp (Note 49)
Note 49. The output level is calculated on the assumption that the signal is not clipped. However, in the actual case, the
SPK-Amp output signal is clipped when DAC outputs 0dBFS signal. The SPK-Amp output level should be kept
under 4.0Vpp (AVDD=3.3V) or 6.0Vpp (SVDD=4.8V) by adjusting digital volume to prevent clipped noise.
Table 61. SPK-Amp Output Level
MS1343-E-00
- 64 -
2011/12