Overvoltage protection circuitry

A method comprising:

• detecting a first voltage between a first implantable electrode and a second implantable electrode, the first voltage generating a current, the first voltage from an external source;
• creating a current path between
• the first implantable electrode,
• a current source configured to source electrical stimulation via the first implantable electrode;
• a capacitor;
• a current sink configured to sink the electrical stimulation via the second implantable electrode;
• and
• the second implantable electrode,
• wherein a respective capacitive characteristic associated with each of the current source and the current sink creates a respective portion of the current path to the capacitor;
• storing at the capacitor, a second voltage from the current received at the capacitor via the current path;
• and
• activating an overvoltage protection element configured to shunt current from at least one of the first implantable electrode or second implantable electrode if the second voltage stored by the capacitor exceeds a threshold of the overvoltage protection element.

A circuit comprising:

• a first implantable electrode;
• a second implantable electrode;
• a first diode configured to allow current, generated by a first voltage across the first implantable electrode and the second implantable electrode, to flow from the first implantable electrode to an internal node in of the circuit, wherein the internal node is configured to allow a second voltage of the internal node to raise in response to the current generated by the first voltage;
• a capacitor attached to the internal node and configured to receive, via the internal node, a second current at the internal node and store a third voltage with the received second current;
• and
• an overvoltage protection element configured to shunt current from at least one of the first implantable electrode or second implantable electrode if the third voltage store by the capacitor exceeds a threshold voltage of the overvoltage protection element.

A medical device comprising:

• means for detecting a first voltage between a first implantable electrode and a second implantable electrode, the first voltage generating a current, the first voltage from an external source;
• means for creating a current path between
• the first implantable electrode,
• a current source configured to source electrical stimulation via the first implantable electrode;
• a capacitor;
• a current sink configured to sink the electrical stimulation via the second implantable electrode;
• and
• the second implantable electrode,
• wherein a respective capacitive characteristic associated with each of the current source and the current sink creates a respective portion of the current path to the capacitor;
• means for storing, at the capacitor, a second voltage from the current received at the capacitor via the current path;
• and
• means for activating an overvoltage protection element configured to shunt current from at least one of the first implantable electrode or second implantable electrode if the second voltage stored by the capacitor exceeds a threshold of the overvoltage protection element.