Synchronous Rectifier To Optimize The Psm Circuit Reliability Design

The power IC has been dramatically developed thanks to the fast growing of the electronic products market, the rapid development of information technology as well as the adequate motivation of technology innovation. In addition, electronic products have been multifunctional, for example, a cell phone can also be used as a PDA, a digital camera, a MP3 and other things, which means the design of electronic products has been increasingly complicated. Therefore, the transient response impact caused by the switching of the power can be more and more serious during the working process of electronic products. The large current and large voltage led by the switching can bring certain disturbances to the system. Moreover, the switching also leads to thermal effects and some other problems, which can not be neglected. So, under this situation, the reliability of power IC has drawn increasing attention. This thesis is focus on its analysis and design. What's more, an IC chip of PSM based on BOOST control topology was designed, which has a boost range of 4~4.5V to 5V, a transfer efficiency of more than 80% under light load situation, with the reliability design of over-voltage protection, over-temperature protection, over-current protection and soft start circuits.The main work of this thesis is as follows:Chapter1 gives the reasons why reliability design plays an indispensable role in the power supply system. It also provides an overview of commonly used topologies and modulation technologies of power IC.Chapter2 is consists of analysis of a variety of abnormal situations during Power IC's operating process, summary of commonly used structures of protection circuits. Design of a chip based on 3um P-Well N-Sub CMOS process is the main idea ofchapter3. The chip based on the optimized PSM, can be applied in BOOST control topology. This section emphasizes the control strategy, the state transition and the specie application of reliability technology. It also covers the introduction and simulation results of some major sub circuits.Chapter4 and chapter5 analysis the simulation results of the whole chip, the layout design and the test results of the taped-out chip. Followed the summary, improvements of the chip and prospects of future works are pointed out.