AK4950 Datasheet, PDF (36/106 Pages) Asahi Kasei Microsystems – 24bit Stereo CODEC with MIC/SPK/Cap-less VIDEO-AMP & mini DSP

[AK4950]
■ MIC Power
When PMMP bit = “1”, the MPWR pin supplies the power for microphones. This output voltage is typically 2.5V
@MICL bit =“0” (AVDD=3.0 ~ 3.6V), and typically 2.2V@MICL bit = “1” (AVDD=2.7 ~ 3.6V). The load resistance is
minimum 0.5kΩ. In case of using two sets of stereo microphones, the load resistance is minimum 2kΩ for each channel.
Any capacitor must not be connected directly to the MPWR pin (Figure 27).
The MIC power performance is deteriorated considerably when output the MIC power and SPK-amp at the same time
since the MPWR pin output uses VSS3 (SPK-amp VSS). Simultaneous operation of MIC power and SPK-amp is not
recommended.
PMMP bit
MPWR pin
0
Hi-Z
1
Output
Table 23. MIC Power
(default)
MIC Power
MPWR pin
LIN1 or LIN2
RIN1 or RIN2
Mi c ro phon e
Mi c ro phon e
Figure 27. MIC Block Circuit
MS1320-E-00
- 36 -
2011/10