Abstract: A position sensing device (PSD) comprising: a light source that provides light responsive to current that it receives; a power source that provides current to the light source through a load line; a photodetector that receives an amount of light from the light source that is a function of position of the light source relative to the photodetector; and an integrated circuit comprising an I/O port connected to the light source and having a plurality of selectable states; wherein different selectable states determine different values for the load line and therefore current provided to the light source.