ak4646 AKM Semiconductor, Inc., ak4646 Datasheet - Page 31

• Manufacturer Part Number: ak4646
• Description: Stereo Codec With Mic/spk-amp
• Manufacturer: AKM Semiconductor, Inc.

■
The AK4646 has a gain amplifier for microphone input. The gain of MIC-Amp is selected by the MGAIN2-0 bits (Table
19). The typical input impedance is 30k Ω (typ).
■
When PMMP bit = “1”, the MPWR pin supplies power for the microphone. This output voltage is typically 0.8 x AVDD
and the load resistance is minimum 0.5k Ω . In case of using two sets of stereo microphone, the load resistance is minimum
2k Ω for each channel. Any capacitor must not be connected directly to MPWR pin (Figure 23).
MS0557-E-02
MIC Gain Amplifier
MIC Power
MGAIN2 bit
0
0
0
0
1
1
1
1
MIC Power
MGAIN1 bit
PMMP bit
0
1
0
0
1
1
0
0
1
1
Figure 23. MIC Block Circuit
Table 19. Mic Input Gain
Table 20. MIC Power
MPWR pin
LIN1 pin
RIN1 pin
LIN2 pin
RIN2 pin
MGAIN0 bit
- 31 -
MPWR pin
0
1
0
1
0
1
0
1
Output
Hi-Z
Input Gain
+20dB
+26dB
+32dB
+10dB
+17dB
+23dB
+29dB
(default)
0dB
Microphone
Microphone
Microphone
Microphone
(default)
[AK4646]
2007/05