User manual

Chapter 4 Connecting Signals

input multiplexers on the device. The PGIA converts two input signals to a

signal that is the difference between the two input signals multiplied by the

gain setting of the amplifier. The amplifier output voltage is referenced to

the ground for the device. Your device A/D converter (ADC) measures this

output voltage when it performs A/D conversions.

You must reference all signals to ground either at the source device or at

the device. If you have a floating source, you should reference the signal to

ground by using the RSE input mode or the DIFF input configuration with

bias resistors. To do so, refer to the Differential Connections for

Nonreferenced or Floating Signal Sources section in this chapter. If you

have a grounded source, you should not reference the signal to AIGND.

You can avoid this reference by using DIFF or NRSE input configurations.

Connecting Your Analog Input Signals

The following sections discuss the use of single-ended and differential

measurements and make recommendations for measuring both floating

and ground-referenced signal sources.

Figure 4-3 summarizes the recommended input configuration for both

types of signal sources.

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