AK4950 Datasheet, PDF (34/106 Pages) Asahi Kasei Microsystems – 24bit Stereo CODEC with MIC/SPK/Cap-less VIDEO-AMP & mini DSP

[AK4950]
■ MIC/LINE Input Selector
The AK4950 has an input selector. INL and INR bits select LIN1/LIN2 and RIN1/RIN2, respectively. When DMIC bit =
“1”, digital microphone input is selected regardless of INL and INR bits.
DMIC bit
0
1
INL bit
INR bit
Lch
Rch
0
0
LIN1
RIN1
0
1
LIN1
RIN2
1
0
LIN2
RIN1
1
1
LIN2
RIN2
0
0
0
1
1
0
Digital Microphone
1
1
Table 20. MIC/Line In Path Select (x: Don’t care, N/A: Not available)
(default)
■ MIC Gain Amplifier
The AK4950 has a gain amplifier for microphone input. The gain of MIC-Amp is selected by the MGAIN3-0 bits (Table
21). The typical input impedance is 30kΩ.
MGAIN3 bit
0
0
0
0
0
0
0
0
1
MGAIN2 bit MGAIN1 bit MGAIN0 bit Input Gain
0
0
0
0dB
0
0
1
+5dB
0
1
0
+8dB
0
1
1
+11dB
1
0
0
+14dB
1
0
1
+16dB
1
1
0
+18dB (default)
1
1
1
+21dB
0
0
0
+24dB
Others
N/A
(N/A: Not available)
Table 21. Input Gain
MS1320-E-00
- 34 -
2011/10