ak4537 AKM Semiconductor, Inc., ak4537 Datasheet - Page 26

• Manufacturer Part Number: ak4537
• Description: 16-bit 6 Stereo Codec With Mic/hp/spk-amp
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
„ MIC Gain Amplifier
AK4537 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 30k .
The mic gain amp of the AK4537 supports the following three cases:
„ MIC Power
The MPI and MPE pins supply power for the Microphone. These output voltages are 0.75 x AVDD (typ) and the
maximum output current is 1.25mA.
MS0202-E-04
MIC Rch
MIC Lch
External
External
Internal
Internal
MIC
MIC
MIC
MIC
MGAIN bit
MICR
MICL
EXT
EXT
Figure 20. External MIC (Mono)
Figure 19. Internal MIC (Mono)
0
1
INT
INT
Table 14. MIC Input Gain
Figure 21. Stereo MIC
Input Gain
- 26 -
MSEL= “0”
MSEL= “1”
MSEL= “0”
+20dB
0dB
PMMICR bit = “0”
PMMICR bit = “0”
PMMICR bit = “1”
PMMICL bit = “1”
PMMICL bit = “1”
PMMICL bit = “1”
Default
MICOUTL
MICOUTR
MICOUTL
MICOUTR
MICOUTL
MICOUTR
[AK4537]
2005/04