A Boost Current Mode Control Of Pwm Switching Power Supply Controller

This paper presents the analysis, design and simulation results of a current feedback PWM DC-DC converter. Based on BCD technology and used the tools of Cadence EDA, a type of a single-chip switching power supply management IC is designed to match the demanding of request. It works at high frequency with a selectable pin outside; the working frequency is fixed at 640K/1.2MHz. So far as the output signal of the single-chip IC is concerned, the maximum time proportion of its high level is 88 percent, but the minimum one is 10 percent. In sum, the single-chip IC is ideal for generating bias voltages for LCD panels.In this paper, the bias theory of switch power type is given firstly. Then introduce the boost mode particularly. In meantime, the all sub-circuits are also designed and emulated carefully including Error Amplifier, voltage reference circuit, voltage comparator, RS type flip-flop, Soft-start circuit, sawtooth-wave generator, PWM comparator, current added circuit and so on. As a result, all of the sub-circuits answer the requirements.At last, two types mode (CCM and DCM) of the synthetic circuit is emulated. The results of emulation meet the function requirement. Based on its application, the efficiency and of the convertor is ploted as well as the output voltage with different loads. The results of emulation meet the function requirements. The forward design of single-chip switching power supply management IC has been finished.