AN10E40 Data Manual
7
2nd Order Sallen-Key Filter for Output Smoothing
20
0
2nd Order
I
O
Z
-40dB/Decade
dB
X
Y
-20
-40
-60
Frequency [Hz]
Figure 6. A 2nd Order Sallen-Key Filter for Output Smoothing
4th Order Sallen-Key Filter for Output Smoothing
I
O
Z
I
O
Z
20
0
4th Order
-80dB/Decade
dB
X
Y
X
Y
-20
-40
-60
Frequency [Hz]
Figure 7. A 4th Order Sallen-Key Filter for Output Smoothing
Here, the first stage of filtering is handled by an otherwise unused IO cell. It can instead be one of the two spare op-
amps the AN10E40 provides. (See the Pin Out Description section for a description of pins 24, 25, 74 and 75.)
2nd Order Sallen-Key Filter for Input Anti-Aliasing
20
2nd Order
I
O
Z
-40dB/Decade
dB
0
-20
-40
-60
X
Y
Frequency [Hz]
Figure 8. A 2nd Order Sallen-Key Filter for Input Anti-Aliasing
LATTICE [ LATTICE SEMICONDUCTOR ]
