AK4640_05 AKM [Asahi Kasei Microsystems], AK4640_05 Datasheet - Page 29

• Manufacturer Part Number: AK4640_05
• Description: 16-Bit ?? CODEC with MIC/HP/SPK-AMP
• Manufacturer: AKM [Asahi Kasei Microsystems]

ASAHI KASEI
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.
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.
MS0273-E-02
MIC Gain Amplifier
MIC Power
MIC Power
MIC-Amp
MGAIN bit
0
1
Table 14. MIC Input Gain
Figure 19. MIC Power
MPI/MPE
INT/EXT
Input Gain
- 29 -
+20dB
0dB
≥ 2kΩ
Default
Microphone
[AK4640]
2005/04