Single-ended Mode

The single-ended mode has only one input relative to ground and it suitable for connecting with the floating signal source. The floating source means it does not have any connection to ground. Figure 3.4 shows the single-ended connection. Note that when more than two floating sources are connected, the sources must be with common ground.

Figure 4.2.1 Floating source and single-ended

Differential input mode

The differential input mode provides two inputs that respond to the difference signal between them. If the signal source has one side connected to local ground, the differential mode can be used for reducing ground loop. Figure 3.5 shows the connection of the differential input mode. However, even if the signal source is local grounded, the single- ended still can be used when the Vcm (Common Mode Voltage) is very small and the effect of ground loop can be negated.

Ground

Signal

Source

 

n

=

 

 

n =

0, ..., 8 0,

…

 

To A/D Converter

 

 

AIHn

 

 

+

-

AILn

GND

Vcm = VG1 - VG2

VG1

VG2

Figure 4.2.2 Ground source and differential input

Operation Theorem ∙ 29