AK5701VNP AKM Semiconductor Inc, AK5701VNP Datasheet - Page 36

• Manufacturer Part Number: AK5701VNP
• Description: IC ADC AUDIO STER 16BIT 24QFN
• Manufacturer: AKM Semiconductor Inc
• Type: ADCr

Specifications of AK5701VNP

• Resolution (bits): 16 b
• Sampling Rate (per Second): 7.35k ~ 48k
• Data Interface: I²S, Serial
• Voltage Supply Source: Analog and Digital
• Voltage - Supply: 3V
• Operating Temperature: -30°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-WFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 974-1039-2; AK5701VNP

2. ALC Recovery Operation
The ALC recovery operation waits for the WTM1-0 bits
If the input signal does not exceed “ALC recovery waiting counter reset level”
recovery operation is executed. The IVL and IVR values are automatically incremented by RGAIN1-0 bits
to the set reference level
Then the IVL and IVR are set to the same value for both channels. The ALC recovery operation is executed at a period set
by WTM1-0 bits. If ZTM1-0 is longer than WTM1-0 and no zero crossing occurs, the ALC recovery operation is
executed at a period set by ZTM1-0 bits.
For example, when the current IVOL value is 30H and RGAIN1-0 bits are set to “01”, IVOL is changed to 32H by the
auto limiter operation and then the input signal level is gained by 0.75dB (=0.375dB x 2). When the IVOL value exceeds
the reference level (REF7-0), the IVOL values are not increased.
When
during the ALC recovery operation, the waiting timer of ALC recovery operation is reset. When
the waiting timer of ALC recovery operation starts.
The ALC operation corresponds to the impulse noise. When the impulse noise is input, the ALC recovery operation
becomes faster than a normal recovery operation. When large noise is input to microphone instantaneously, the quality of
small level in the large noise can be improved by this fast recovery operation.
MS0404-E-02
“ALC recovery waiting counter reset level (LMTH1-0) ≤ Output Signal < ALC limiter detection level (LMTH1-0)”
“ALC recovery waiting counter reset level (LMTH1-0) > Output Signal”,
WTM1
0
0
1
1
(Table
WTM0
RGAIN1
0
1
0
1
REF7-0
27) with zero crossing detection which is timeout period set by ZTM1-0 bits
0
0
1
1
EFH
F1H
F0H
E2H
E1H
E0H
03H
02H
01H
00H
Table 27. Reference Level at ALC Recovery operation
Table 25. ALC Recovery Operation Waiting Period
:
:
1024/fs
128/fs
256/fs
512/fs
Table 26. ALC Recovery GAIN Step
RGAIN0
0
1
0
1
GAIN(dB)
+35.625
+30.375
+29.625
−53.625
+35.25
−53.25
MUTE
+36.0
+30.0
−54.0
ALC Recovery Operation Waiting Period
128ms
8kHz
16ms
32ms
64ms
:
:
(Table
- 36 -
1 step
2 step
3 step
4 step
GAIN STEP
25) to be set after completing the ALC limiter operation.
16kHz
16ms
32ms
64ms
0.375dB
8ms
0.375dB
0.750dB
1.125dB
1.500dB
Step
(Table
(default)
44.1kHz
(default)
11.6ms
23.2ms
22) during the wait time, the ALC
2.9ms
5.8ms
(default)
(Table
(Table
[AK5701]
2007/08
26) up
24).