AK4490EN Datasheet, PDF (65/68 Pages) Asahi Kasei Microsystems – Premium 32-Bit 2ch DAC

[AK4490EN]
It is recommended for SACD format book (Scarlet Book) that the filter response at SACD playback is an
analog low pass filter with a cut-off frequency of maximum 50kHz and a slope of minimum 30dB/Oct. The
AK4490EN can achieve this filter response by combination of the internal filter (Table 40) and an external
filter (Figure 42).
Table 40. Internal Filter Response at DSD Mode
Frequency
Gain
20kHz
0.4dB
50kHz
2.8dB
100kHz
15.5dB
AOUT-
2.0k
2.8Vpp
2200p
AOUT+
+
2.0k
2.8Vpp
1.8k
3300p
1.8k
4.3k
4.3k
1.0k
1.0k
270p
270p
+Vop
-
+
-Vop
Analog
Out
6.34Vpp
Figure 42. External 3rd Order LPF Circuit Example for DSD
Table 41. 3rd Order LPF (Figure 42) Response
Frequency
Gain
20kHz
0.05dB
50kHz
0.51dB
100kHz
16.8dB
DC gain = 1.07dB
015013666-E-01
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2015/12