AK4695 Datasheet, PDF (28/107 Pages) Asahi Kasei Microsystems – 24bit 4ch CODEC with MIC/HP/SPK/LINE-AMP

[AK4695]
■ MIC Power
When PMMPA/B bit = “1”, the MPWRA/B pin supplies power for the microphones. This output voltage is typically 2.4V
(0.857 x AVDD) and the load resistance is minimum 250 for the MPWRA pin and minimum 500 for the MPWRB pin.
Any capacitor must not be connected directly to the MPWRA and MPWRB pins (Figure 18).
MIC power can be switched ON/OFF regardless of the ADC status. However, the voltage at the microphone input pin will
be shifted and need time to return to the VCOM voltage when power up the MIC power during the ADC is powered on.
This recovery time to the VOCM voltage is dependent on the capacitance of the input capacitor and the time constant of the
input impedance.
PMMPA bit
MPWRA pin
0
Hi-Z
(default)
1
Output
Table 16. Output Setting of MIC Power A
PMMPB bit
MPWRB pin
0
Hi-Z
(default)
1
Output
Table 17. Output Setting of MIC Power B
MIC Power
“PMMPA”
“PMMPB”
MPWRA pin
MPWRB pin
MICIN0L pin
MICIN0R pin
MICIN1L pin
MICIN1R pin
MICIN2L pin
MICIN2R pin
MICIN3L pin
MICIN3R pin
Figure 18. MIC Block Circuit
Microphone
Microphone
Microphone
Microphone
Microphone
Microphone
Microphone
Microphone
MS1463-E-01
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2014/12