An implantable medical device includes a low-power circuit, a high-power circuit, and a dual-cell power source. The power source is coupled to a dual-transformer such that each cell is connected to only one of the transformers. Each transformer includes multiple windings and each of the windings is coupled to a capacitor, and the capacitors are all connected in a series configuration. The low power circuit is coupled to the power source and issues a control signal to control the delivery of charge from the power source to the plurality of capacitors through the first and second transformers.