Novel voltage-mode hysteretic controlled two-stage VRM

With the development of microprocessors, voltage regulator module (VRM) is required to have many strict and challenging specifications. Its main topology and control scheme must follow the fast-developing trend. Two-stage VRM can solve issues such as the increasing input voltage, improving power and quickly dynamic response. It is easy to achieve the goal of high frequency, current division and high power density when the interleaving technique is utilized in the second-stage. A novel voltage-mode hysteretic control scheme is proposed and it has many advantages over many other control techniques that include simplicity, no feedback loop compensation is needed, near instantaneous response to load transients, and no limitations on the switches ON time. From this, it is clear that combining the novel voltage-mode hysteretic control technique with the two-stage technique will result in a VRM that has the advantages of both techniques. The working principle of novel voltage-mode hysteretic controlled two-stage VRM is discussed; its advantages are proved by PSPICE simulation and experiments.