Connecting Differential Voltage Inputs - Data Translation DT3010 Series Getting Started Manual

Connecting Differential Voltage Inputs

Figure 19A illustrates how to connect a floating signal source to the
DT740 or STP268 screw terminal panel using differential inputs. (A
floating signal source is a voltage source that has no connection with
earth ground.) For floating signal sources, you need to provide a bias
return path by adding resistors R1 to R16 for channels 0 to 15,
respectively.
If the input signal is +10 V, then the common-mode voltage could be
1 V. Theoretically, the resistor value (R
input bias current (20 nA) or 50 mΩ. However, when you add noise
from external sources to the high impedance, a resistor value of 100 Ω
to 100 kΩ is more practical.
In Figure 19B, the signal source itself provides the bias return path;
therefore, you do not need to use bias return resistors. R
source resistance while R
bridge. Note that the negative side of the bridge supply must be
returned to analog ground.
Figure 20 illustrates how to connect a floating signal source to the
STP268-EC screw terminal panel.
) should be 1 V divided by the
b
is the resistance required to balance the
v
Wiring Signals
5
5
5
5
is the signal
s
5
5
5
5
5
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