AK4637EN Datasheet, PDF (88/96 Pages) Asahi Kasei Microsystems – 24bit Mono CODEC with MIC/SPK-AMP

[AK4637]
■ Digital Microphone Input
FS3-0 bits
(Addr:06H, D3-0)
Timer Select
(Addr:09H)
1011
(1)
00H
(2)
ALC Setting
(Addr:0AH, 0BH)
REF7-0 bits
(Addr:0CH)
IVOL7-0 bits
(Addr:0DH)
60H,00H
(3)
E1H
(4)
E1H
(5)
Filter Select
(Addr:16H,17H,21H)
Digital Filter Path
(Addr:18H)
01H,00H,00H
(6)
03H
(7)
Filter Co-efficient
xxH
(Addr:19H-20H,22H-3FH)
(8)
ALC State
ALC Disable
1011
00H
6CH,2EH
E1H
E1H
6CH,0EH
(13)
01H,xxH,xxH
03H
xxH
ALC Enable
ALC Disable
Example:
PLL Master Mode
Audio I/F Format: I2S Compatible
Sampling Frequency: 48kHz
Digital MIC setting:
Data is latched on the DMCLK falling edge.
ALC setting: Refer to Table 37
HPF1: fc=3.7Hz, ADRST1-0 bits = “00”
(1) Addr:06H, Data:0BH
(2) Addr:09H, Data:00H
(3) Addr:0AH, Data:6CH
Addr:0BH, Data:2EH
(4) Addr:0CH, Data:E1H
(5) Addr:0DH, Data:E1H
(6) Addr:16H, Data:01H
Addr:17H, Data:xxH
Addr:21H, Data:xxH
(7) Addr:18H, Data:03H
(8) Addr:19H-20H, Data:xxH
Addr:22H-3FH, Data:xxH
(9) Addr:00H, Data:C0H
PMPFIL bit
(Addr:00H, D5)
Digital MIC
(Addr:08H)
SDTO pin
State
(9)
00H
11H
1059/fs
(10)
0 data output
Normal
Data ouput
(12)
00H
(11)
0 data output
(10) Addr:08H, Data:11H
Recording
(11) Addr:08H, Data:00H
(12) Addr:00H, Data:40H
(13) Addr:0BH, Data:0DH
Figure 71. Digital Microphone Input Recording Sequence
<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 PLL mode, Digital Microphone of
(11) and Programmable Filter of (10) must be powered-up in consideration of PLL lock time after
a sampling frequency is changed.
(2) Set up FRN, FRATT and ADRST1-0 bits (Addr = 09H)
(3) Set up ALC mode. (Addr = 0AH, 0BH)
(4) Set up REF value for ALC (Addtr = 0CH)
(5) Set up IVOL value at ALC operation start (Addr = 0DH)
(6) Set up Programmable Filter ON/OFF (Addr = 16H, 17H, 21H)
(7) Set up Programmable Filter Path: PFSDO bit = ADCPF bit = “1” (Addr = 18H)
(8) Set up Coefficient of Programmable Filter (Addr:19H ~ 20H, 22H ~ 3FH)
(9) Power Up Programmable Filter: PMPFIL bit = “0” → “1”
(10) Set Up & Power Up Digital Microphone: DMIC = PMDM bits = “0” → “1”
The initialization cycle time of ADC is 1059/fs=22ms@ fs=48kHz, ADRST1-0 bit = “00”. ADC
outputs “0” data during initialization cycle. After the ALC bit is set to “1”, the ALC operation starts
from IVOL value of (5).
(11) Power Down Digital Microphone: PMDM bit = “1” → “0”
(12) Power Down Programmable Filter: PMPFIL bit = “1” → “0”
(13) ALC Disable: ALC bit = “1” → “0”
015010680-E-00
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2015/09