Voltage regulator module

A voltage regulator module (VRM), sometimes called processor power module (PPM), is a buck converter that provides microprocessor and chipset the appropriate supply voltage, converting +3.3 V, +5 V or +12 V to lower voltages required by the devices, allowing devices with different supply voltages be mounted on the same motherboard. On personal computer (PC) systems, the VRM is typically made up of power MOSFET devices. Most voltage regulator module implementations are soldered onto the motherboard. Some processors, such as Intel Haswell and Ice Lake CPUs, feature some voltage regulation components on the same CPU package, reduce the VRM design of the motherboard; such a design brings certain levels of simplification to complex voltage regulation involving numerous CPU supply voltages and dynamic powering up and down of various areas of a CPU. A voltage regulator integrated on-package or on-die is usually referred to as fully integrated voltage regulator (FIVR) or simply an integrated voltage regulator (IVR). Most modern CPUs require less than 1.5 V, as CPU designers tend to use lower CPU core voltages; lower voltages help in reducing CPU power dissipation, which is often specified through thermal design power (TDP) that serves as the nominal value for designing CPU cooling systems. Some voltage regulators provide a fixed supply voltage to the processor, but most of them sense the required supply voltage from the processor, essentially acting as a continuously-variable adjustable regulator. In particular, VRMs that are soldered to the motherboard are supposed to do the sensing, according to the Intel specification. Modern video cards also use a VRM due to higher power and current requirements. These VRMs may generate a significant amount of heat and require heat sinks separate from the GPU. The correct supply voltage is communicated by the microprocessor to the VRM at startup via a number of bits called VID (voltage identification definition).