AK4635 AKM [Asahi Kasei Microsystems], AK4635 Datasheet - Page 37

• Manufacturer Part Number: AK4635
• Description: 16-Bit Mono CODEC with ALC & MIC/SPK/Video-AMP
• Manufacturer: AKM [Asahi Kasei Microsystems]

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When power-up, the PDN pin should be “L” and change to “H” after all power are supplied. “L” time of 150ns or more
is needed to reset in the AK4635.
The ADC enters an initialization cycle when the PMADC bit is changed from “0” to “1”. The initialization cycle time is
1059/fs, or 133ms@fs = 8kHz. 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 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.
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When the internal device temperature rises up irregularly (e.g. output pins of speaker amplifier are shortened), the
AK4635 is powered down automatically and then THDET bit becomes “1”. The powered-down speaker amplifier do not
return to normal operation unless SPK-Amp blocks of the AK4635 are reset by the PDN pin “L”. The device status can be
monitored by THDET bit.
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The AK4646 has an input selector. When MDIF bit is “0”, LIN bit selects MIC pin or LIN pin. When MDIF bit is “1”,
full-differential input is available.
Rev. 0.6
System Reset
Thermal Shut Down
MIC/LINE Input Selector
When Off-set becomes a problem, lengthen initialization time of ADC as ADRST bit = “0” or do not use initial
output data of ADC.
ADRST bit
MDIF bit
0
1
MIC/MICP pin
LIN/MICN pin
0
0
1
LIN bit
1059/fs
291/fs
0
1
x
Cycle
AK4635
Table 19. Input Select (x: Don’t care)
Table 18 Initialization cycle of ADC
Figure 36 Input Selector
Input circuit
Single-End
Single-End
Differential
MDIF bit
LIN bit
fs = 8kHz
132.4ms
- 37 -
36.4ms
Init Cycle
MICP/MICN pin
fs = 16kHz
Input pin
MIC pin
LIN pin
66.2ms
18.2ms
ADC
(default)
fs = 48kHz
22.1ms
6.1ms
[AK4635]
2007/10