Hi all,
Does anyone know of a circuit that converts a (linear) current into an exponential voltage of the form V = e^(x) -1 (-1 term necessary to start at 0V).
I've looked at a Sharp application note (vorlon.case.edu/~flm/eecs245/ Datasheets/Sharp%20photodevices.pdf) where on page 6 they have a simple current - to - voltage conversion using photo transistor and op amp. The graph (fig 13B) indicates a somewhat exponential output Voltage - has anyone used this circuit before?
I appreciate the input is light intensity and not current, but was hoping to replace photo transistor with BJT.
Cheers, Ozzy