What is VRM?
A Voltage Regulator Module (VRM) is an electrical circuit which regulates the output voltage. A VRM has various applications including, but not limited to, motherboards, load regulators, mechatronics, robotics, custom sensors, and cameras.
In computers, a VRM acts as a buck converter which steps down an incoming Direct Current (DC) voltage to provide a lower DC voltage at its output. The VRM’s incoming voltage from a Power Supply Unit (PSU) is around 12 Volts (V) while the outgoing voltage is regulated at less than 1.5 V, which is reduced to match the required operating voltage of the components connected at its output such as Integrated Circuits (IC), Graphics Processing Units (GPU), or Central Processing Units (CPU). VRMs connected to a GPU or a CPU work in a similar fashion. Since the VRM output supplies the input voltage or power to computer’s processing units, the VRM is also known as a Processor Power Module (PPM).
Some CPUs come equipped with VRMs and, therefore, do not require them separately on the motherboard. However, VRMs can be plugged into a (multi-socket) motherboard to supply appropriate voltage to one or more processors (with same or slightly different voltage requirements). Some VRMs provide a fixed supply voltage to the processor, while others can sense the required supply voltage from the processor and act as a continuously-variable adjustable regulator for a small range of voltages.
The IC connected at the VRM’s output may get destroyed if it receives a higher voltage than its maximum operating voltage. Continuous operation of VRM over a long period can dissipate a large amount of heat, and therefore it needs a heat sink. The low operating voltage of the processing unit ensures minimal power consumption and reduced heat dissipation, which helps in designing effective cooling systems.