Disclosed is an electrical isolator circuit comprising an input stage comprising first and second inputs, the input stage being configured to receive an input voltage signal; an output stage comprising first and second outputs electrically connected across a load capacitor; and a DC isolator comprising a first capacitor between said first input and said first output and second capacitor between said second input and said second output. The first and second plates of each of the first, second and load capacitors are defined by conductive layers of a printed circuit board and the dielectric of each of the first, second and load capacitors are defined by a non-conducting part of the printed circuit board.