AK4537 Datasheet, PDF (26/76 Pages) Asahi Kasei Microsystems – 16-Bit ΔΣ Stereo CODEC with MIC/HP/SPK-AMP

ASAHI KASEI
[AK4537]
„ 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 30kΩ.
MGAIN bit
Input Gain
0
0dB
1
+20dB
Default
Table 14. MIC Input Gain
The mic gain amp of the AK4537 supports the following three cases:
Internal
MIC
External
MIC
INT
PMMICL bit = “1”
MICOUTL
EXT
MSEL= “0”
PMMICR bit = “0”
MICOUTR
Internal
MIC
External
MIC
Figure 19. Internal MIC (Mono)
INT
PMMICL bit = “1”
MICOUTL
EXT
MSEL= “1”
PMMICR bit = “0”
MICOUTR
MIC Lch
MIC Rch
Figure 20. External MIC (Mono)
MICL
MICR
PMMICL bit = “1”
MICOUTL
MSEL= “0”
PMMICR bit = “1”
MICOUTR
Figure 21. Stereo MIC
„ 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
- 26 -
2005/04