Implantable medical system with external power charger

An external charger for an implantable medical device, the implantable medical device having a secondary coil in a patient, the external charger comprising:

• a housing forming an internal compartment;
• electronic components disposed on a printed circuit board assembly disposed within the internal compartment;
• and
• a recharge coil assembly disposed within the internal compartment, the recharge coil assembly including:
• a recharge coil configured to output power to the secondary coil via inductive power transfer wherein the recharge coil is planar;
• and
• a planar flux guide having a planar flexible ferrite sheet, the ferrite sheet located between the recharge coil and the printed circuit board assembly and the ferrite sheet is disposed alongside the recharge coil.

An external charger for an implantable medical device having a secondary coil in a patient, the external charger comprising:

• a housing forming an internal compartment;
• electronic components disposed on a main printed circuit board assembly disposed within the internal compartment;
• and
• a recharge coil assembly disposed within the internal compartment, the recharge coil assembly including:
• an insulative bobbin having a first major surface and an opposite second major surface;
• a recharge coil disposed on the first major surface of the insulative bobbin and coupled to the electronic components to form a resonant recharge tank circuit, the recharge coil configured to output power to the secondary coil via inductive power transfer, wherein the recharge coil is planar and wound around the insulative bobbin;
• a telemetry coil disposed concentric to the recharge coil on the first major surface of the insulative bobbin and operably coupled to the electronic components to form a resonant telemetry tank circuit configured to communicate with the implantable medical device via inductive telemetry;
• and
• a planar flux guide having a planar ferrite sheet disposed on the second major surface of the insulative bobbin and between the recharge and telemetry coils and the main printed circuit board assembly and the ferrite sheet is disposed alongside the recharge coil and the insulative bobbin.