Combination charging and telemetry circuit for use within an implantable medical device uses a single coil for both charging and telemetry that is controlled via the use of an opto-switch. One or more capacitors are used to tune the coil to different frequencies for receiving power from an external device and for the telemetry of information to and from an external device. The opto-switch is coupled to the resonant circuit, but because its input is electrically decoupled from its output, it easy to control.