ak4650 AKM Semiconductor, Inc., ak4650 Datasheet - Page 27

• Manufacturer Part Number: ak4650
• Description: 16bit 6 Codec With Mic/hp/spk-amp & Tsc
• Manufacturer: AKM Semiconductor, Inc.

L
The AK4650 has a Gain Amplifier for Microphone input. The gain is 0dB or +20dB, selected by the MGAIN bit. The
typical input impedance is 30k .
L
The MPI and MPE pins supply power for the Microphone. These output voltages are 2.2V (typ) and load resistance is
2k (min). MPWRI and MPWRE bits control output from MPI and MPE pins, respectively. When LNMP bit = “1”, MPE
pin becomes LIN pin.
L
The AK4650 includes the detection function of microphone.
Example of the detection of external microphone.
When RNMD bit = “1”, MDT pin becomes RIN pin.
MS0502-E-01
MIC Gain Amplifier
MIC Power
MIC Detection Function
(1) MPWRE bit = “1”.
(2) MPE drives external microphone.
(3) DTMIC bit is set by Table 13.
Input Level of MDT
> 0.247V
< 0.165V
Table 12. External Microphone Power Supply (x: Don’t care)
Table 11. Internal Microphone Power Supply (x: Don’t care)
PMMIC bit
PMMIC bit
0
1
0
1
MGAIN bit
Table 13. Microphone detection result
0
1
MPWRI bit
MPWRE bit
Table 10. MIC Input Gain
DTMIC bit
x
0
1
x
0
1
1
0
Input Gain
- 27 -
+20dB
0dB
MPI pin
MPE pin
Output
Output
Hi-Z
Hi-Z
Hi-Z
Hi-Z
External microphone
(default)
Disconnect
Connect
(default)
(default)
[AK4650]
2007/04