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AK4112B_12 Datasheet, PDF (12/31 Pages) Asahi Kasei Microsystems – High Feature 96kHz 24bit DIR | |||
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[AK4112B]
 De-emphasis Filter Control
The AK4112B includes the digital de-emphasis filter (tc=50/15µs) by IIR filter corresponding to four sampling
frequencies (32kHz, 44.1kHz, 48kHz and 96kHz). When DEAU bit=â1â, the de-emphasis filter is enabled automatically
by sampling frequency and pre-emphasis information in the channel status. The AK4112B goes this mode at default.
Therefore, in Parallel Mode, the AK4112B is always placed in this mode and the de-emphasis filter is controlled by the
status bits in channel 1. In Serial Mode, DEM0/1 and DFS bits can control the de-emphasis filter when DEAU is â0â.
When the â0â data is input to the de-emphasis filter, the output data will be â0â or â-1â. The internal de-empahsis filter is
bypassed and the recovered data is output without any change if either pre-emphasis or de-emphasis Mode is OFF.
FS96 FS1
0
0
0
0
0
1
0
1
1
0
1
0
1
1
1
1
FS0 Mode
0
44.1kHz
1
OFF
0
48kHz
1
32kHz
0
OFF
1
OFF
0
96kHz
1
OFF
Table 7. De-emphasis Auto Control at DEAU=â1â and PEM=â1â
DFS DEM1 DEM0 Mode
0
0
0 44.1kHz
0
0
1
OFF Default
0
1
0
48kHz
0
1
1
32kHz
1
0
0
OFF
1
0
1
OFF
1
1
0
96kHz
1
1
1
OFF
Table 8. De-emphasis Manual Control at DEAU=â0â and PEM=â1â
MS0078-E-03
- 12 -
2012/01
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