[AK4634]
■ Speaker Output
AK4634 has a Mono Class-D Speaker-Amp. Power supply for Speaker-Amp(SVDD) can be set from 2.2V up to 4.0V.
The Speaker is mono and BTL output, and can drive dynamic speaker and piezo speaker without LPF (filter-less). This
speaker can output 400W@8Ω at SVDD = 3.3V, SPKG bit = “0”. This gain is set by SPKG bit (Table 37). The output
level of speaker amp is depended on voltage of SVDD and SPKG bit.
SPKG bit
Gain
0dB
+2dB (Note 33)
0
1
Note 33. The signals more than -2dBFS clip.
Table 37. SPK- Amp Gain
The power up/down speaker amp is controlled by PMSPK bit. When PMSPK bit is “0”, the SPP and SPN pins output
VSS3 level. Also ON/OFF of speaker amp is controlled by SPOUTE bit. When SPOUTE bit is “0”, the SPP and SPN pins
are in VSS3-state forcibly. When the outputting from DAC to speaker, PMDAC bit should be set to “1”.
Follow the following sequence.
P M S P K b it
S P O U T E b it
S P P p in
N o rm a l O u tp u t
S P N p in
N o rm a l O u tp u t
Figure 43. Power-up/Power-down Timing for Speaker-Amp
Rev. 0.5
2007/10
- 51 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
