EXTERNALLY POWERED IMPLANTABLE STIMULATOR

An example method includes receiving, by an implantable device and from an external device, an energy signal; transducing, by the implantable device, the energy signal into electrical power; outputting, by the implantable device and to the external device, a feedback signal that represents an absolute level of the electrical power transduced from the energy signal, wherein the feedback signal includes a first portion that represents a relative level of the electrical power transduced from the energy signal and a second portion that represents a reference voltage level; and delivering, by the implantable device, a level of electrical stimulation therapy proportional to the absolute level of the electrical power transduced from the energy signal.