A fully integrated feedback controlled coil driver (500) is disclosed for inductive power transfer to electronic devices. For efficient power transfer, a voltage across a switch (516) that switchably couples the coil (512) between a DC input power source (501) and ground is sampled and compared with a preselected reference voltage (536) to generate an error voltage (542). The error voltage (542) is integrated over time and compared to a voltage ramp (554). The value of the integrated error voltage relative to the voltage ramp is used to obtain an optimal on time for the switch (516) such that coil current is maximized for a given DC input power.
