AK4636 Datasheet, PDF (40/105 Pages) Asahi Kasei Microsystems – 16-Bit Mono CODEC with ALC & MIC/SPK/Video-AMP

[AK4636]
■ MIC Gain Amplifier
The AK4636 has a Gain Amplifier for Microphone input. These gains are selected by the MGAIN3-0 bit. The typical
input impedance is 30kΩ.
MGAIN3 bit
0
0
0
0
0
0
0
0
1
1
MGAIN2 bit MGAIN1 bit MGAIN0 bit Input Gain
0
0
0
0dB
0
0
1
+20dB
0
1
0
+26dB
0
1
1
+32dB
1
0
0
+10dB
1
0
1
+17dB
1
1
0
+23dB
1
1
1
+29dB
0
0
0
+3dB
0
0
1
+6dB
Others
N/A
Table 20. Input Gain (N/A: Not available)
(default)
■ MIC Power (DMPE bit = “0”)
The MPI pin supplies power for the Microphone. This output voltage is 2.3V (typ) and the load resistance is minimum
2kΩ. Any capacitor must not be connected to the MPI pin directly.
MPI pin
≥ 2k
MIC pin
MIC-Power
AK4636
MIC-Amp
A/D HPF
Audio
I/F
BICK pin
FCK pin
STDO pin
Figure 37. MIC Block Circuit
MPI pin
1k
MICP pin
MICNpin
1k
MIC-Power
AK4636
MIC-Amp
A/D HPF
Audio
I/F
BICK pin
FCK pin
STDO pin
Figure 38. MIC Block Circuit (Differential; MDIF = “1”)
MS1012-E-01
- 40 -
2010/08