AK4560A Datasheet, PDF (44/47 Pages) Asahi Kasei Microsystems – 16bit CODEC with ALC and MIC/HP/SPK-Amps

ASAHI KASEI
[AK4560A]
n FADEIN Mode
In FADEIN Mode, the IPGA value is increased at the value set by FDATT when FDIN bit changes from “0” to “1”.
The update period can be set by FDTM1-0 bits. The FADEIN Mode is always detected by the zero crossing operation.
This operation is kept over the REF value or until the limiter operation at once. If the limiter operation is done during
FADAIN cycle, the FADEIN operation becomes the ALC operation.
NOTE: When FDIN and FDOUT bits are “1”, FDOUT operation is enabled.
IPGA Ouput
ALC1 bit
FDIN bit
(5)
(1) (2)
(3)
(4)
Figure 35. Example for controlling sequence in FADEIN operation
(1) WR (ALC1 = FDIN = “0”): The ALC1 operation is disabled. To start the FADEIN operation, FDIN bit is written in
“0”.
(2) WR (IPGA = “MUTE”): The IPGA output is muted.
(3) WR (ALC1 = FDIN = “1”): The FADEIN operation starts. The IPGA changes from the MUTE state to the FADEIN
operation.
(4) The FADEIN operation is done until the limiter detection level (LMTH) or the reference level (REF6-0). After
completing the FADEIN operation, the AK4560A becomes the ALC1 operation.
(5) FADEIN time can be set by FDTM1-0 and FDATT bits
E.g. FDTM1-0 = 1024/fs @ fs =48kHz = 21.3ms, FDATT = 1step
(96 x FDTM1-0) / FDATT = 96 x 21.3ms / 1 = 2.04s
MS0028-E-00
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2000/05