Research On Key Technologies Of Digital Controlled VRM

In current years, digital power is becoming a research hot spot in power electronics. It causedacademic and industrial attention widely due to its high reliability, parameter consistency, algorithmagile, programmable monitoring etc, but the problems like limit cycle oscillation, delay effect affectits application. With the growth of the CPU integration, the corresponding requirement to voltageregulator modular (VRM) is also gradually improved. The power supply dropped down to about1V,while the current increased to hundreds of ampere. Combined with the particularity of the CPU, theconverter is working between the sleep mode and the active mode continually, so the requirements tothe dynamic response of the system are high. In this paper, the digital control method is applied to theVRM design, and some meaningful work has been done in both system modeling and circuitimplementation.First, through the combination of switching capacitor unit and PWM unit, the flyback switchingcapacitor voltage regulator is achieved. Not only the system dynamic performance is improved, butalso the poor output voltage adjustment ability of switching capacitor converter is changed. Later, theprinciple of circuit is analyzed.Then, the flyback switching capacitor voltage regulator is chosen as power circuit, the digitalcontrolled VRM based on PX3538is modeled. Each part is modeled, so the understanding to systemis more impressive.At last, the main circuit parameters are designed. The AVP design is given to the circuit based onthe modeling of the whole system. The experimental and simulational results coincide with theexpected specification.Finally, the whole design work is concluded and some further research directions are given.