A voltage regulator module (e.g., a VRM) can be used to regulate a DC voltage supplied to a load, such as a microprocessor. A VRM can include a power converter, such as a DC-DC converter, and may include other components such as a controller for controlling operation of the power converter.
An example of a DC-DC converter is a synchronous buck converter, which has minimal components, and therefore is widely used in VRM applications. In an example application, the input voltage to the buck converter is typically 12VDC. An output voltage produced by the VRM may be 5.0VDC, 3.3 VDC, or lower.
Multiphase interleaved VRM topologies include two or more power converters operated in parallel with each other to convert power and apply it to a corresponding load. In each of the power converters (or each power converter phase), the filter inductor can be smaller than that of a single phase power converter in order to achieve a faster dynamic response. The large output voltage ripple in each phase due to the small inductance can be cancelled by the ripple of other phases. Use of more phases in parallel reduces the ripple voltage. Implementation of a multiphase voltage converter topology (as compared to a single voltage converter phase topology) can therefore enhance the output current capability of a power supply system.
A typical configuration of a VRM such as a so-called synchronous buck converter includes an inductor, a high side switch, and a low side switch. A controller associated with the buck converter repeatedly pulses the high side switch ON to convey power from a power source through the inductor to a dynamic load. The controller repeatedly pulses the low side switch ON to provide a low impedance path from a node of the inductor to ground in order to control an output of the buck converter. Thus, the energy stored in the inductor increases during a time when the high side switch is ON and decreases during a time when the low side switch is ON. During switching operation, the inductor transfers energy from the input to the output of the converter.