AK4637 Datasheet, PDF (87/96 Pages) Asahi Kasei Microsystems – 24bit Mono CODEC with MIC - SPK-AMP

[AK4637]
■ Microphone Input Recording
FS3-0 bits ₁₀₁₁
(Addr:06H, D3-0)
(1)
MGAIN3-0 bits
PMMP bit
0,110,0
(Addr:02H, D6,D2-0, D3)
(2)
Signal Select
(Addr:03H, D3)
Timer Select
(Addr:09H)
ALC Setting
(Addr:0AH, 0BH )
REF7-0 bits
(Addr:0CH)
IVOL7-0 bits
(Addr:0DH)
Filter Select
(Addr:16H,17H,21H)
Digital Filter Path
(Addr:18H)
0
(3)
00H
(4)
60H,00H
(5)
E1H
(6)
E1H
(7)
01H,00H,00H
(8)
03H
(9)
Filter Co-efficient
xxH
(Addr:19H-20H, 22H-3FH)
(10)
ALC State
ALC Disable
1011
0,110, 1
0
00H
6CH,2EH
E1H
E1H
01H, xxH,xxH
03H
xxH
ALC Enable
6CH,0EH
(13)
ALC Disable
Example:
PLL Master Mode
Audio I/F Format: I2S Compatible
MIC Amp: +18dB
MIC Power: ON
Sampling Frequency: 48kHz
ALC setting: Refer to Table 37
HPF1: fc=3.7Hz, ADRST1-0 bits = “00”
(1) Addr:06H, Data:0BH
(2) Addr:02H, Data:0EH
(3) Addr:03H, Data:00H
(4) Addr:09H, Data:00H
(5) Addr:0AH, Data:6CH
Addr:0BH, Data:2EH
(6) Addr:0CH, Data:E1H
(7) Addr:0DH, Data:E1H
(8) Addr:16H, Data:01H
Addr:17H, Data:xxH
Addr:21H, Data:xxH
(9) Addr:18H, Data:03H
(10) Addr:19H-20H,Data:xxH
Addr:22H-3FH, Data:xxH
PMPFIL bit
PMADC bit
(Addr:00H, D7, D0)
(11) _1059/fs
(11) Addr:00H, Data:C1H
(12)
Recording
SDTO pin
State
0 data Output
Initialize
Normal
Data Output
0 data output
Figure 70. Microphone Input Recording Sequence
(12) Addr:00H, Data:40H
(13) Addr:0BH, Data:0EH
<Sequence>
This sequence is an example of ALC setting at fs= 48kHz. For changing the parameter of ALC,
please refer to Table 37. At first, clocks should be supplied according to “Clock Set Up” sequence.
(1) Set up a sampling frequency (FS3-0 bits). When the AK4637 is in PLL mode, Microphone,
ADC and Programmable Filter of (12) must be powered-up in consideration of PLL lock time
after a sampling frequency is changed.
(2) Set up Microphone Amp and Microphone Power. (Addr = 02H)
(3) Set up Input Signal. (Addr = 03H)
(4) Set up FRN, FRATT and ADRST1-0 bits (Addr = 09H)
(5) Set up ALC mode. (Addr = 0AH, 0BH)
(6) Set up REF value at ALC (Addtr = 0CH)
(7) Set up IVOL value at ALC operation start (Addr = 0DH)
(8) Programmable Filter ON/OFF Setting (Addr: 16H, 17H, 21H)
(9) Set up Programmable Filter Path: PFSDO bit = ADCPF bit = “1” (Addr = 18H)
(10) Set up Coefficient Programmable Filter (Addr: 19H ~ 20H, 22H ~ 3FH)
(11) Power Up Microphone Amp, ADC and Programmable Filter: PMADC =PMPFIL bits = “0” → “1”
The initialization cycle time of ADC is 1059/fs=22ms @ fs=48kHz, ADRST1-0 bit = “00”. ADC
outputs “0” data during the initialization cycle. After the ALC bit is set to “1”, the ALC operation
starts from IVOL value of (7).
(12) Power Down Microphone Amp, ADC and Programmable Filter: PMADC = PMPFIL bits = “1” →
“0”
(13) ALC Disable: ALC bit = “1” → “0”
015010680-E-00
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2015/09