Intrinsically safe automation field device

An intrinsically safe field device of automation technology for use in an explosion-hazard area, comprising:

• a first and a second connection terminal for connecting a two-wire line via which a current can be supplied;
• a sensor element or an actuator element for capturing or setting a process variable;
• field device electronics connected to the first and the second connection terminals, the field device electronics including:
• a current path from the first to the second connection terminal;
• and
• a voltage regulator incorporated into the current path, the voltage regulator being designed to provide, on the basis of the supplied current, a power supply at least for the sensor element or the actuator element,
• wherein the field device electronics are designed to transmit the process variable, captured via the sensor element, by setting the supplied current to a corresponding value, or to receive the process variable, to be set by the actuator element, by reading the supplied current and adjusting the actuator element accordingly;
• and
• an explosion protection unit, including:
• a first and a second actively-controllable switching element, incorporated into the current path in series;
• and
• a first and a second threshold value circuit designed such that the first threshold value circuit controls the first controllable switching element as a function of a first threshold value of the supplied current, and the second threshold value circuit controls the second controllable switching element as a function of a second threshold value of the supplied current such that, upon the first or the second threshold value being reached, the supplied current is limited to the first or the second threshold value,
• wherein the threshold value circuits are connected in parallel to the voltage regulator incorporated into the current path.