| With the rapid growth of portable electronic products’ share in the field of industrial control and consumer goods, power integrated circuit industry is in rapid development at an alarming rate, becoming one of the most popular research and production area in IC industry. Most of the portable electronic products use battery for power supply. However, in many portable electronic products, the supply voltage required is larger than the voltage battery provided, that is why a boost converter is needed.This thesis studies a high efficiency PWM control current mode boost DC-DC converter. In the beginning, this paper introduces the fundamental theory and control method of DC-DC boost converter. The DC-DC boost converter circuit uses the PWM modulation method, that is, the pulse width modulation method and the peak current control mode, which has high sampling rate to output signal, to stabilize the output voltage. Then, the thesis introduces the architecture of DC-DC converter. The chip features internally a power switch for high converter efficiency. The chip responds quickly, has high precision of output voltage and high conversion efficiency. With the deep analysis of the power loss, some corresponding measures are taken to achieve the aim of low loss and high efficiency, such as synchronous rectifier technology, cross-zero detecting circuit, high efficiency bandgap reference and current amplifier.The DC-DC boost conversion also includes three protective circuits: under voltage lockout protection, over temperature protection and soft start circuit. Under the condition that the input voltage is too low or the temperature is too high, the under voltage lockout protection or the over temperature protection circuit will disable the DC-DC boost converter. The soft start circuit makes the converter able to avoid the overshoot voltage and surge current during the start-up stage. These circuits protect the DC-DC boost converter from the damage result from working on unsuitable environment, which can improve the converter’s service life. Apart from the work which has been mentioned above, the layout is completed.The chip uses 0.35?m BCD manufacturing process of XinTang. Circuit design uses Spectre of Candence for simulation. System level simulation has been made in four important indexes. The simulation shows the system’s regulation rate is 0.933%, the regulation rate of load is 2.46(%/A), the ripple is under 20 mV,the highest converter efficiency is 91%.According to the simulation data which is given above, the very DC-DC boost converter has achieved the high efficiency request. |
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