AK4636 Datasheet, PDF (39/105 Pages) Asahi Kasei Microsystems – 16-Bit Mono CODEC with ALC & MIC/SPK/Video-AMP

[AK4636]
■ System Reset
When power-up, the PDN pin should be “L” and change to “H” after all powers are supplied. “L” time of 150ns or more
is needed to reset the AK4636.
The ADC enters an initialization cycle when the PMADC bit is changed from “0” to “1”. The initialization cycle time is
set by ADRST bit (Table 18). During the initialization cycle, the ADC digital data outputs of both channels are forced to
a 2's compliment, “0”. The ADC output reflects the analog input signal after the initialization cycle is complete. The same
initializing cycle is occurred when using the digital microphone. The DAC does not require an initialization cycle.
(Note) Off-set occurs in the initial data depending on the conditions of a microphone and cut-off frequency of HPF.
When Off-set becomes a problem, lengthen initialization time of ADC by ADRST bit = “0” or do not use initial
output data of ADC.
ADRST bit
0
1
Init Cycle
Cycle
fs = 8kHz
fs = 16kHz
1059/fs
132.4ms
66.2ms
291/fs
36.4ms
18.2ms
Table 18 Initialization cycle of ADC
fs = 48kHz
22.1ms
6.1ms
■ MIC/LINE/Digital MIC Selector
The AK4636 has an input selector. When MDIF bit is “0”, LIN bit selects the MIC pin or LIN pin. When MDIF bit is “1”,
MIC/LIN pins become MICP/MICN pins, and full-differential input is available. When DMIC bit is “1”, MIC/LIN pins
become DMCLC/ DMDAT pins, and they can be connected to digital microphone.
MDIF bit
0
0
1
x
LIN bit
0
1
x
x
DMIC bit
Input circuit
Input pin
0
Single-Ended
MIC pin
0
Single-Ended
LIN pin
0
Differential
MICP/MICN pin
1
Digital MIC
DMDAT/ DMCLK pin
Table 19. Input Select (x: Don’t care)
(default)
MS1012-E-01
- 39 -
2010/08