Abstract: A mixed-mode integrated circuit (IC) device includes power circuitry formed on an IC die. The power circuitry generates multiple operating voltages. Additional circuitry is formed on other IC dies that are vertically stacked with the first IC die, which serves both as a carrier for the other IC dies and as a silicon interposer on which the power supply and DC-to-DC converter circuits are formed. Coaxial connectors are coupled to the power circuit arrangement and provide each circuit with an appropriate operating voltage. Thus, digital, analog, and radio frequency functions can be incorporated in a single package. Methods of forming the same are similarly included within the scope of the present invention.