Hspice Typical Software-based Psm And Pwm Integrated Circuit Design And Performance Comparison

Pulse Width Modulation(PWM) is a traditional and wide-used modulation for power IC. It regulates the output voltage by changing the duty cycle of the pulses on the switch power device. Pulse Skip Modulation(PSM) is a novel method to modulate the power IC, of which the power device skips different periods to obtain a stable output voltage. PWM has a small ripple, but slow response and low efficiency for light loads, while PSM has a much higher efficiency for light loads, and quicker response, but higher ripple. So there are both advantages and disadvantages for each other.This dissertation designed a basic PWM chip and a basic PSM chip by Viewdraw, Hspice and etc. Then connect the two chips into the Boost converters, and compare them by the simulations of Hspice in the complexity for design, efficiency, ripple, response, and so on. A new optimized PSM modulation, which has the advantages of both of the basic PWM and basic PSM, is then proposed in this paper. At last the optimized PSM chip is laid out by Virtuoso Layout Editor and Dracula, then taped out and tested.The key works in the dissertation are in:(1) The frame of the basic PSM chip;(2) The design and simulation of the error amplifier, and the oscillator by Hspice and Viewdraw;(3) The comparison of the two basic chips in ripple, response rate, and the efficiency by Hspice;(4) The layout of the optimized PSM chip by Virtuoso Layout Editor.The creative points in this paper are in:(1) The design for frequency dimension of the error amplifier, and the compensation for coordinating the zeros and poles;(2) The compensation for temperature of the oscillator.