一种高效率dcdc开关电源芯片的设计-design of a high efficiency dcdc switching power supply chip.docxVIP

一种高效率 DC/DC 开关电源芯片的设计DESIGN OF A HIGH EFFICIENCY DC/DC SWITCHING POWER SUPPLY CHIPABSTRACTIn recent years, with portable electronic equipments being widely used, there are more requirements for power supplies. Electronic equipments are becoming smaller and lower cost, which is leading to power supplies lighter, smaller, thinner and more efficient. For its low power consumption and high efficiency, switching power supply becomes very popular now.As one of the control methods, peak current control realizes the dual-loop control on the basis of voltage mode control by applying current feedback, which can improve the stability and transient response performance of the system. As one of the most popular modulation methods used in the switching power supplies, pulse width modulation(PWM) has been favored for its high precision and excellent ability of avoiding noise interference. Based on the background mentioned above, a peak current control PWM boost chip is presented.The proposed chip uses Chartered 0.35μm n-well CMOS process model with switching frequency of 500 kHz, and integrated with high precision voltage reference, oscillator, current sensing circuit, slope compensation circuit, error amplifier, and synchronous rectification driver circuit and so on. Among them, the reference source circuit adopts a structure with current mode, which could make the adjustment of reference voltage easily. Thanks to the novel current sensing circuit presented, the power consumption can be reduced. The adaptive slope compensation circuit could supply an optimal compensation slope with respect to the input and the output voltages. The chip also has overcurrent protection circuit and standby function, which could improve the chip performance in stability and efficiency. The simulation results show as follows: output voltage can be maintained at about 3.3V with the input voltage between 1.3V to 3V; In the condition of typical application, output voltage ripple is less than ±1%, and chi