FEDL2215-01
Semiconductor
ML2215
1
10. Low Pass Filter
ML2213’s analog output goes through the built-in Low Pass Filter. The Figure 10.1 below shows Frequency
Characteristics and Table 10.1 shows Cut-off Frequency of the LPF.
No analog output passing through the LPF is available on this chip.
[dB] 20
10
0
–10
–20
–30
–40
–50
–60
–70
–80
10
100
1 k
10 k
[Hz]
Figure 10.1 LPF Frequency Characteristics (fSAM = 8 kHz)
Table 10.1 LPF Cut-off Frequency
Sampling Frequency (kHz)
(fSAM
Cut-off Frequency (kHz)
(fCUT
)
)
4.0
5.3
1.2
1.6
2.0
2.5
3.2
4.0
5.0
6.4
8.0
10.6
12.8
16.0
11. AOUT Connecting Circuit
It is recommended to connect a capacitor of 0.01 to 0.033 µF to the AOUT pin.
The circuit diaram is as shown below.
AOUT
0.01 to 0.033 µF
The capacitor is used for improving a voice quality. Check the voice quality before determining the capacitor
value. If the voice quality is excellent without connecting a capacitor, no capacitor is required.
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