ak4358 AKM Semiconductor, Inc., ak4358 Datasheet - Page 33

• Manufacturer Part Number: ak4358
• Description: 192khz 24-bit 8ch Dac With Dsd Input
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
4. External Analog Filter
It is recommended by 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 slop of minimum 30dB/Oct. The AK4358 can achieve this filter
response by combination of the internal filter (Table 18) and an external filter (Figure 27).
MS0203-E-01
AOUT+
AOUT-
AOUT+
AOUT-
2.5Vpp
2.5Vpp
2.5Vpp
2.5Vpp
Figure 28. External 2
Figure 27. External 3rd order LPF Circuit Example
Table 18. Internal Filter Response at DSD mode
Table 19. 3rd order LPF (Figure 27) Response
2.0k
2.0k
2200p
3.9k
3.9k
Frequency
Frequency
100kHz
100kHz
3900p
20kHz
50kHz
20kHz
50kHz
4.7k
DC gain = 1.07dB
nd
order LPF Circuit Example for PCM
1.8k
1.8k
3300p
When R1=180 Ω
When R1=150 Ω
- 33 -
R1
R1
fc=90.1kHz, Q=0.735, g=-0.04dB at 40kHz
fc=99.0kHz, Q=0.680, g=-0.23dB at 40kHz
4.3k
470p
4.7k
-15.5dB
-0.05dB
-0.51dB
-16.8dB
-0.4dB
-2.8dB
Gain
Gain
1.0k
1.0k
+Vop
-Vop
470p
270p
4.3k
+Vop
-
+
-Vop
270p
Analog
Out
Analog
6.05Vpp
Out
5.65Vpp
[AK4358]
2006/02