Research And Design Of Power Management Chip Based On PWM Current Mode Control

DC-DC converters as key interface have been widely used in communication systems, computers, and consumer electronics etc. In recent years, with the fast development of portable electronic products, DC-DC converters are well developed. Power management chips, the heart of electronic systems, play a crucial roll on the performance of electronics. So it is valuable in the view of both economy and research to design high efficiency, high frequency and small scale DC-DC converters.In the thesis, kinds of DC-DC converters'topologies are introduced first. Then CCM and DCM converters are completely described. The advantages and disadvantages of modulate modes and control types are compared. Also the key techniques and compensation of current mode PWM buck DC-DC converters are completely analyzed.Each sub-circuit is designed reasonably according to the principle and character of PWM DC-DC converter, such as: error amplifier (EA), bandgap, oscillator, comparator, current sensing and compensation circuits, over temperature protection (OTP), under voltage lock out (UVLO). It is analyzed in detail that how to realize every sub-circuits'functions according to different needs. At last, simulation results, which can show that the circuit is correct, are given partly.