AK5397 Datasheet, PDF (34/44 Pages) Asahi Kasei Microsystems – 32-Bit Stereo Premium ADC

[AK5397]
■ Digital Output Data
The AK5397 has two kinds of output data. These data are sent from SDTO1 and SDTO2 pins at the
same time. The SDTO1 pin is passed through “Sharp Roll-off” and the SDTO2 pin is passed through
“Short Delay Filter” or “Minimum Phase Filter” selected by the SDFIL pin as shown by Table 12.
When fs=384kHz, 768kHz, the AK5397 does not support “Short Delay Filter” and “Minimum Phase
Filter”. When fs=384kHz, the SDTO1 pin is passed through “Sharp Roll-off Filter”, and the SDTO2 pin is
“L”. When fs=768kHz, the SDTO1 and SDTO2 pins are passed through “Sharp Roll-off Filter” as shown
in Table 10. However, in MONO mode, the SDTO1 pin outputs the data of (Lch+Rch)/2, and the SDTO2
pin is “L” as shown in Table 11.
The output data of SDTO1 and SDTO2 pins can be disabled by using SDM1 and SDM2 pins respectively
as shown in Figure 37, Table 13 and Table 14. However, the SDM2 pin can output data if fs=768KHz
even when the SDM2 pin = “H”.
Sampling Speed SDTO1 Output Data
SDTO2 Output Data
48kHz
Sharp Roll-off Filter
Short Delay Filter
96kHz
Sharp Roll-off Filter
Short Delay Filter
192kHz
Sharp Roll-off Filter
Short Delay Filter
384kHz
Sharp Roll-off Filter
“L” Output
768kHz
Sharp Roll-off Filter (Lch) Sharp Roll-off Filter (Rch)
Table 10. SDTO1 / SDTO2 Output Data (MONO = “L”)
17
Sampling Speed SDTO1 Output Data
SDTO2 Output Data
18
16 15 14
48kHz
Sharp Roll Off Filter
Short Delay Filter
96kHz
Sharp Roll Off Filter
Short Delay Filter
192kHz
Sharp Roll Off Filter
Short Delay Filter
384kHz, 768kHz
Sharp Roll Off filter
(Lch+Rch)/2
“L “Output
Table 11. SDTO1 / SDTO2 Output Data (MONO = “H”)
Delta-Sigma
Modulator
Digital Filter (Sharp)
Digital Filter (Short)
Audio Interface
Audio Interface
SDTO1
SDTO2
Sharp Roll Off Filter Block Short Delay Filter Block
Figure 37. Digital Filter Block
014011535-E-00
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2014/11