Design Of 250MHz Binary PWM Control DC-DC Converter

The developing trend of miniaturing protable electronic products demand for higher energy density of power converter devices.The large size components have become the bottleneck of sizing down the chips,due to the progressing of CMOS process and packaging technology that promote chip sizeshrinking.Fully integrated power converter doesn’t need external components,it remarkably reduces the size and cost of converter,and avoids the external interference effecting on the performance,In recent years,it has become a hot topic in the study of the power converter.Apart from that,improving the efficiency and reducing power loss have been the long-term demand in the design of power converter.As a result,high efficiency,fully integrated power converter is worth studying.A 250 MHz binary PWM control DC-DC converter is presented in this thesis.The implement of the converter can keep stable loop control under high switching frequency,get low output ripple voltage and gain high efficiency at the same time.First of all,the binary PWM control method is analysed and modelled.It is found that the binary PWM control methed features simple control loop and fast transient response.The circuit of power converter is designed followed by the binary PWM control method,which consist of high speed clock control comparator,binary delay line and so on forth,it can work under 250 MHz,control the converter properly.Secondly,stable control block is designed for reducing the output ripple voltage while the output voltage is fixed.Fully MOS reference voltage generating circuit is designed to product a stable reference voltage.Since the converter works in high switching frequency,the relationship between the size of power MOS and energy loss has been analysed to optimaize the size of power MOS and get the optimal efficiency.Finally,an inductor built by bond wire with low parasitic resistance,high inductor value is presented to support the converter operation to achieve fully integrated.In this thesis,the design of 250 MHz binary PWM control DC-DC converter is based the SMIC 55 nm standard process,the schematic and layout design are done.The post-simulation presents that the converter can output current range from 150 mA to 500 mA,maximum efficiency is 64%,output ripple voltage is 40.1mV,and transient respond time is 261 ns.All the results meet the circuit design requirements.