[AK4129]
■ Dither
The AK4129 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 AK4129 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 SRC1-3 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 and SRC3 reflects the DEM[31:30] bits
setting.
DEM11pin
DEM10 pin Mode(SDTI1-3)
L
L
H
H
L
H
L
44.1kHz
OFF
48kHz
32kHz
H
Table 10. De-emphasis Filter Setting (Parallel Control Mode (SPB pin= “L”))
DEM11bit
DEM10 bit
Mode(SDTI1)
44.1kHz
OFF
L
L
H
H
L
H
L
48kHz
32kHz
H
Table 11. De-emphasis Filter Setting for SDTI1 (Serial Control Mode (SPB pin = “H”))
DEM21 bit
DEM20 bit
Mode(SDTI2)
44.1kHz
OFF
L
L
H
H
L
H
L
48kHz
32kHz
H
Table 12. De-emphasis Filter Setting for SDTI2 (Serial Control Mode (SPB pin= “H”))
DEM31 bit
DEM30 bit
Mode(SDTI3)
44.1kHz
OFF
L
L
H
H
L
H
L
48kHz
32kHz
H
Table 13. De-emphasis Filter Setting for SDTI3 (Serial Control Mode (SPB pin = “H”))
MS1173-E-01
2010/09
- 32 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
