Design Of The Comparator Using For Switching Power

With the continuous development of technology of integrated circuit, portable electronic products become more popular in people's life. The problem of battery's life is the most important topic in exploitation of portable products. So, the research of switching power becomes the most hot subject in IC areas. Efficiency is one of the most important characteristics in switching power system. The premise of getting high efficiency is the accurate control to the on-time and off-time of the switch. So, the demand to the comparator block for peak detector in switching power system becomes more and more. As a comparator using in switching power, it must have high gain, suitable bandwidth and small offset voltage. At the same time, it must have a low power dissipation and a short response time. So, the key of designing this kind of comparator is keeping a tradeoff among all parameters of it. In our paper, we analyse and design to this kind of comparator.In the second chapter of this paper, we analysis the principle of these circuits which making of comparator, and state in detail the way for designing the comparator which is using for switching power chips. We also enumerate some kinds of comparator and analysis their advantages and shortcomings.In the 3rd chapter, we design a comparator which is using switching power system. This design uses a bias stage with the structure of negative feedback to get more stable DC bias voltages. The comparator is formed by 3 stages: input stage, a emitter coupled differential pair; middle stage, a folded cascode amplifier and output stage be consisted by a Active Load Inverter.In the fourth chapter of our paper, we give the simulation result in detail. Through the analogous report which is got by Hspice whit a 0.6um biCMOS technologies and 3.6V power supply, we know the comparator has reached our aim. We has got a result that the gain is 104.08dB, the bandwidth is 710. 5kHz, the offset voltage is 0.5mV, the arise response time is 21.7ns, the down response time is 45.9ns and the power dissipation is 76uW. Then we get the advantages and shortcomings of our comparator by compared with other comparators.Last, in conclusion we point out the meaning and shortages of this design and some works needing to do in future.