Analog Output Signal Conditioning - National Instruments BNC-2090A User Manual

Chapter 3 Signal Conditioning

Analog Output Signal Conditioning

BNC-2090A User Manual
Notice that the input impedance for the channels employing voltage
dividers circuit is reduced. In the differential example in Figure 3-9,
the input impedance has been reduced to:
10 kΩ + 10 kΩ + 10 kΩ = 30 kΩ
The reduced input impedance can cause loading errors for signal sources
with large source impedance. In general, the input impedance presented by
the voltage divider circuit must be much larger than the source impedance
of the signal source to avoid signal loading errors.
Each analog output has two open-component positions for passive signal
conditioning components. One is designated as a resistor and one is
designated as a capacitor. Factory-default positions for the 0 Ω jumpers are
R34 and R1 as shown in Figure 3-11.
AO 0
From
DAQ Device
AO GND
AO 1
From
DAQ Device
AO GND
You can remove and/or install components in these locations to build
highpass and lowpass filters. Refer to the
Components section for instructions.
R34
Factory-Installed
0 Ω Jumper
C1
R1
Factory-Installed
0 Ω Jumper
C2
Figure 3-11. AO 0 and AO 1
Adding Signal Conditioning
3-12
AO 0
BNC Connector
AO 1
BNC Connector
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