Currentoutput

Currentoutput is a term used in electronics to describe an output stage that delivers a controlled current to a load, rather than a fixed voltage. A current output regulates the current through the load across a range defined by the source, making the load voltage largely dependent on the load resistance.

In practice, current outputs are common in control and measurement systems. A typical implementation is a current source or a current sink that sets a specified current, such as in 4-20 mA industrial loops. The transmitter or interface generates the current, while the connected load and supply voltage determine the resulting voltages in the loop. The system requires a sufficient compliance voltage—the maximum voltage the output can develop across the load while maintaining the desired current.

There are two basic modes: current source, which drives a load with a set current regardless of load variation, and current sink, which draws a defined current from a source through the load. Some devices combine current outputs with digital control, producing DAC-based current outputs that convert a digital value into a corresponding current.

Applications span process control, instrumentation, and data acquisition, where current outputs offer advantages such as resistance to cable losses and noise over long distances. They enable reliable remote sensing and signaling over extended wiring despite voltage drops.

Design considerations include ensuring adequate compliance voltage, selecting appropriate load resistance, considering wiring and isolation needs, and calibrating for accuracy and temperature effects. See also voltage output, current source, current sink, and current-output DAC.