Process automation device

A method of regulating an analog output of a field device employed in process automation based on an input detected by the field device, the method comprising:

• providing the field device comprising an analog output stage communicatively coupled to a processor of the field device, the analog output stage comprising a regulator module and a switching module;
• obtaining, by the processor, the input detected by the field device, wherein the input comprises a process variable;
• generating, by the processor, a reference pulse width modulated signal configured to output a first analog value based on the input detected by the field device and a predefined analog output that corresponds to the input detected by the field device;
• detecting, by the processor, the analog output;
• alternately providing to the regulator module the first analog value and a second analog value by the switching module, wherein the switching module is driven by a switching pulse width modulated signal generated by the processor, and wherein the second analog value is associated with the detected analog output;
• integrating, by the regulator module, one or more of the first analog value and the second analog value from the switching module, wherein an integrator of the regulator module is configured to smoothen an output from the switching module, which is applied to an input of an operational amplifier of the regulator module;
• generating, by the regulator module, a differential analog output based on the first analog value and the second analog value;
• and
• regulating, by the regulator module, the analog output of the field device based on the differential analog output.