ak4538 AKM Semiconductor, Inc., ak4538 Datasheet - Page 25

• Manufacturer Part Number: ak4538
• Description: 16bit ?? Codec With Mic/hp/spk-amp
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
n MIC Input
The AK4538 has the following functions for Mic Input.
(1) 1
(2) 2
(3) Attenuator for stereo mixer. This volume is controlled by “ATTS2-0” bit as Table 15.
(4) Attenuator for mono mixer. This attenuator level is 4dB and this ON/OFF is controlled by “ATTM” bit.
MS0198-E-01
While ALC is working, Master Clock must be present.
When Master Clock isn’t provided or PMMIC= “0”, it is invalid to write to “IPGA6-0”.
st
nd
MIC Amplifier of 20dB gain that can be selected on/off by “MGAIN” bit.
Amplifier that has PGA with ALC. This volume is controlled by “IPGA6-0” bit as Table 14.
Mic In
0dB/+20dB
“MGAIN”
IPGA6-0
47H
46H
45H
36H
10H
06H
05H
04H
03H
02H
01H
00H
:
:
:
ATTS2-0
Table 14. Microphone Input Gain Setting
7H
6H
5H
4H
3H
2H
1H
0H
IPGA with ALC
“IPGA6-0”
“ALC1”
Figure 19. Microphone Input
Table 15. Attenuator Table
GAIN (dB)
+27.5
+27.0
+26.5
+19.0
+0.0
5.0
5.5
6.0
6.5
7.0
7.5
8.0
Attenuation
:
:
:
- 25 -
-27dB
-6dB
12dB
15dB
18dB
21dB
24dB
9dB
“ATTS2-0”
“MICAD”
“ATTM”
ATT
ATT
0.5dB
STEP
Default
“MICL”
“MICM”
ADC
Default
Stereo Mixer
Mono Mixer
P
[AK4538]
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