.6-bit Programmable Multiphase Synchronous Buck Buck Controller

The rapidly progress of processors indicate the higher operation frequency and larger integration scale while the operation voltage is decreasing. It consistently becomes a big challenge to solve complex power-delivery issues for desktops, workstations, and servers. In fact, powering the microprocessor presents the most difficult power solution in the whole computer system. Faster transients and improved operation over temperature are just a few of the new design requirements. But the most difficult design challenge stems from the fact that the processor needs low voltage with high current power supply. Presently, the core voltage of CPU is about 1V, while the current is as high as 100A and the current transient slew rate has to reach 100A/us.In order to solve the power-delivery problems for CPU, a lot of jobs have been done. Intel proposed VRM/VRD serial standards for its processors. VRM (Voltage Regulator Module) is the newly developed DC-DC converting technique for powering CPU.All kinds of circuit techniques that suits for low voltage high current VRM are well researched, together with Intel VRM/VRD serial standards. A novel 6-bit, programmable, multi-phase synchronous buck controller which is consistent with VRD 10 standard was developed. It can provide reliable VRM scheme to power the popular CPU nowadays.The innovation of the thesis includes: The whole structure of the 6-bit, programmable multi-phase synchronous buck controller was developed and the operation theory was analyzed thoroughly. Some critical techniques in low voltage high current VRM were researched and solved, including precise & lossless output current sensing techniques, current balancing in multi-phase VRM, active impedance control to meet the "droop voltage loadline", complex protection methods and so on.All of the functional building blocks were designed with 1.5 um NSC BCD process and circuit simulation helps to validate the design.