The present invention relates to voltage regulators (VRs), and more specifically to placement of VR components in a system.
Voltage regulators are used in systems such as a personal computer (PC) (e.g., a desktop computer, server computer, notebook computer and the like) to receive input direct current (DC) voltages of a given voltage and convert and regulate such DC voltages to one or more regulated voltage levels required by various system components, such as integrated circuits (ICs) and the like.
In a typical system, for example, a desktop PC, a motherboard is used to support various system components, including ICs, connectors, VR components, and the like. Such VR components may include output inductors, bulk capacitors, metal oxide silicon field effect transistors (MOSFETs), driver ICs, and the like. Typically, the VR components are placed on a primary side (e.g., a topside) of the motherboard. These VR components must be placed outside an IC device's keepout zone (i.e., the IC's footprint, including any socket or heatsink retention). This placement can result in larger loadline lengths and therefore higher loadline impedance (i.e., capacitance, inductance, and resistance). In such manner, VR components may be located many centimeters away from an intended load (e.g., an IC). Accordingly, motherboard/package lateral travel dominates, increasing loadline length and therefore impedance.
Instead of the above described placement of VR components, other systems use some type of additional VR daughter module (i.e., a separate circuit board) that is plugged into the motherboard or an IC device. However, such additional circuit boards increase cost and complexity, and further increase the size of a given form factor. Furthermore, such designs typically provide inferior performance. A need thus exists to provide VR components that have reduced loadline length and impedance.