AK4533 Datasheet, PDF (22/40 Pages) Asahi Kasei Microsystems – Audio Codec with Touch Screen Controller

[ASAHI KASEI]
„Recovery Operation
Recovery Time is defined as a reset cycle of Recovery Counter (RC). The cycle can be changed by the combination of MSEL bit,
RWT0 bit, and RWT1 bit. Input signal enters Recovery Zone from other Zones, RC initiates counting. If the signal exits from
Recovery Zone at lease once, RC is reset. When RC's value exceeds Recovery Time, the AK4533 is ready to update IPGA value, and
RC is reset and counts again from "zero". IPGA value is actually updated once just after the signal crosses the ground. Therefore, the
update cycle will change. Note that the update is one time in one Recovery Time and that the update of IPGA value is disabled until
ROC is "zero" even if the signal crosses the ground several times. The AK4533 compares the IPGA value and Recovery Reference
Level at the update timing. If IPGA value is greater than Recovery Reference Level, IPGA value is forced to Recovery Reference
Level.
When the input signal enters Recovery Zone from any other Zones at the first time, the AK4533 waits for one Recover Time without
updating of IPGA. After that, the AK4533 updates IPGA per one Recovery Time at zero-crossing point.
If the signal doesn't cross the ground, the AK4533 forces to update IPGA value after the time of Table 5 passes.
MSEL
Zero-Cross Timeout
“L”
252Ts
8kHz
11.025kHz
22.05kHz
44.1kHz
31.5ms
22.9ms
11.4ms
NA
“H”
508Ts
8kHz
11.025kHz
22.05kHz
44.1kHz
NA
NA
NA
11.5ms
Table 5. Zero-Cross Timeout Table for Recovery Time
Addr = 01h RSTEP-0: Recovery GAIN Step
RSTEP0 bit and RSTEP1 bit specify the increment step size of IPGA value at Recovery operation. For example, if the current value of
IPGA is 0x42, and if RSTEP0 and RSTEP1 are "11", IPGA is set to 0x46.
Default
RSTEP1
0
0
1
1
RSTEP0
0
1
0
1
GAIN STEP
0.5dB
1.0dB
1.5dB
2.0dB
Addr = 01h RWT1-0: Recovery Time
MSEL RWT1 RWT0
0
0
0
256Ts
Default
0
0
1
512Ts
0
1
0
1024Ts
0
1
1
2048Ts
1
0
0
512Ts
1
0
1
1024Ts
1
1
0
2048Ts
1
1
1
4096Ts
8kHz
32ms
64ms
128ms
256ms
-
-
-
-
Recovery Time
11.025kHz
23ms
46ms
93ms
185ms
-
-
-
-
22.05kHz
11.6ms
23ms
46ms
93ms
-
-
-
-
44.1kHz
-
-
-
-
11.6ms
23ms
46ms
93ms
<Revision 0.9a>
21
July 00