AK4640_05 Datasheet, PDF (29/78 Pages) Asahi Kasei Microsystems – 16-Bit ΔΣ CODEC with MIC/HP/SPK-AMP

ASAHI KASEI
[AK4640]
„ MIC Gain Amplifier
AK4640 has a Gain Amplifier for Microphone input. This gain is 0dB or +20dB, selected by the MGAIN bit (Table 14).
The typical input impedance is 30kΩ.
MGAIN bit
Input Gain
0
0dB
1
+20dB
Default
Table 14. MIC Input Gain
„ MIC Power
The MPI and MPE pins supply power for the Microphone. These output voltages are 0.75 x AVDD (typ) and the load
resistance is 2kΩ(min). No capacitor must be connected directly to MPI and MPE pins.
MIC Power
MPI/MPE
≥ 2kΩ
MIC-Amp
INT/EXT
Microphone
Figure 19. MIC Power
MS0273-E-02
- 29 -
2005/04