While many instruments such as amplifiers and filters may receive differential
signals, it is generally the case that they only provide single-ended output.
In some cases it may be necessary to acquire signals from a single-ended device.
Driving the differential input from a single-ended output must be done correctly
to avoid noise pickup.
Figure illustrates the proper connections. Note that both the shield and the negative lead of the differential pair are tied to the ground at the single-ended driving source. When connecting to a device with a coaxial connector, then the shield and negative lead are tied to the shield of the coaxial connector. If the driving source is some distance away and particularly if it is powered from a power source that is derived from a different power distribution center, then it may be necessary to provide a heavy ground strap between the single-ended analog source and the differential input instrumentation to minimize currents flowing through the shield of the twisted pair cable. Refer to the section on grounding.