2-30
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Chapter 2
Analog Input and Temperature Sensor Measurements
Choose a capacitor that has the following suggested characteristics:
•
AXL or RDL package
•
Tolerance of 20%
•
Maximum voltage of at least 25 V
Adding Components for Highpass Filtering on Analog
Input Signals
Using the circuit shown in Figure 2-27, you can use a two-component circuit to build a simple
RC filter with an analog input.
•
Differential analog input highpass filter
—To build a differential highpass filter, add the
resistor to position E and the capacitor to position F, as shown in Figure 2-28. Refer to
Table 2-1 for component positions for all analog input channels.
The SCB-68A ships with a surface mount 0
Ω
resistor in the F position. You
must
remove
the resistor to use the position.
Figure 2-28.
SCB-68A Circuit Diagram for Differential Analog Input Highpass Filter
•
Single-ended analog input highpass filter
—To build a single-ended highpass filter, refer
to Figure 2-29. Add the resistor to position B or D, depending on the AI channel you are
using. Add the capacitor to position F or G, depending on the AI channel you are using.
Refer to Table 2-1 for component positions for all analog input channels.
The SCB-68A ships with a surface mount 0
Ω
resistor in the F and G positions. You
must
remove the resistor to use the position.
AI
i
AI
i
+
8
y
S
C
x
E
A
F
G
B
C
D
+
+
+
+ 5 V
AI GND
+ 5 V
AI GND
AI
i
AI
i
+
8
