Transmission of industry standard 4-20mA current loop signals to values and other actuators is a common requirement. Resistive line losses and actuator impedances require current transmitters to be able to force a compliance voltage of a least 20V. Because of this, 5V powered systems usually cannot meet current loop transmitter requirements, but Figure 10 shows a way to do this. This 5V powered circuit utilizes a servo controlled DC/DC converter to generate the compliance voltage necessary for loop current requirements. It will drive 4-20mA into loads as high as 2200Ω (44V compliance) and is inherently short-circuit protected.