One embodiment of the present subject matter includes a method for pulse generation in an implantable device, comprising measuring an impedance between a first electrode and a second electrode and delivering a pulse based on a pulse energy level and a pulse duration limit, comprising generating a pulse duration as a function of the pulse energy level and the impedance and selecting a capacitance value from a plurality of capacitances in a partitioned capacitor bank to deliver a pulse at the pulse energy level and wherein the pulse duration is less than the pulse duration limit.
