AK4128A Datasheet, PDF (32/50 Pages) Asahi Kasei Microsystems – 8ch 216kHz / 24-Bit Asynchronous SRC

[AK4128A]
■ Dither
The AK4128A includes a dither circuit. The dither circuit adds a dither signal after the lowest bit of all the output data set
by the OBIT1-0 pins when the DITHER pin = “H”, regardless of SRC and SRC bypass modes. If the output bit is 24bit
length in SRC bypass mode, the output code does not change by the DITHER pin setting.
■ De-emphasis Filter
The AK4128A includes a digital de-emphasis filter (tc = 50/15μs) by an IIR filter. This filter corresponds to three
frequencies (32kHz, 44.1kHz and 48kHz). In parallel control mode (SPB pin = “L”), de-emphasis setting of SRC1-4 are
controlled together by DEM1-0 pins. In serial control mode (PSB pin = “H”), the setting of DEM1-0 pins is ignored. SRC1
reflects the DEM[11:10] bits setting, SRC2 reflects the DEM[21:20] bits setting, SRC3 reflects the DEM[31:30] bits
setting, and SRC4 reflects the DEM[41:40] bits setting.
DEM11pin DEM10 pin Mode(SDTI1-4)
L
L
44.1kHz
L
H
OFF
H
L
48kHz
H
H
32kHz
Table 10. De-emphasis Filter Setting (Parallel Control Mode (SPB pin= “L”))
DEM11bit DEM10 bit Mode(SDTI1)
L
L
44.1kHz
L
H
OFF
H
L
48kHz
H
H
32kHz
Table 11. De-emphasis Filter Setting for SDTI1 (Serial Control Mode (SPB pin = “H”))
DEM21 bit DEM20 bit Mode(SDTI2)
L
L
44.1kHz
L
H
OFF
H
L
48kHz
H
H
32kHz
Table 12. De-emphasis Filter Setting for SDTI2 (Serial Control Mode (SPB pin= “H”))
DEM31 bit DEM30 bit Mode(SDTI3)
L
L
44.1kHz
L
H
OFF
H
L
48kHz
H
H
32kHz
Table 13. De-emphasis Filter Setting for SDTI3 (Serial Control Mode (SPB pin = “H”))
DEM41 bit DEM40 bit Mode(SDTI4)
L
L
44.1kHz
L
H
OFF
H
L
48kHz
H
H
32kHz
Table 14. De-emphasis Filter Setting for SDTI4 (Serial Control Mode (SPB pin = “H”))
MS1242-E-00
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2010/09