摘要在集成电路设计中,有一个不可缺少的单元模块,那就是基准电压电路。在各种模拟集成电路、混合集成电路中,它都有被广泛地应用。比如模数(A/D)及数模(D/A)转换器等。芯片的供电电压和功耗随着集成电路特征尺寸的越来越小也在不断的降低,所以对基准源性能方面要求也就越来越高。基准源的温度稳定性以及电源电压抑制比(PSRR)等参数将影响整个电路系统的性能。同时,随着数模混合IC的不断进步,对基准源的有些参数比如温度系数、低功耗设计和电源抑制比(PSRR)都提出了更高的标准。这些要求无疑使得带隙基准源的设计承担了更艰巨的任务。带隙基准源在电源管理芯片中有着不可轻忽的地位,它是最基础、最重要的单元模块,而高性能的带隙基准源则是研究的重中之重。我们所说的高性能的带隙基准源,它包含很多方面的性能指标。比如,低温度系数的带隙基准源,这种带隙基准源让基准源的输出随温度的改变而改变的比较轻微;还有高电源抑制比(PSRR)的基准源,它能让带隙基准源具备更高的抗干扰能力;电源调整率(Line Regulation)较低的带隙基准源,这种基准源随着电源电压的改变其对基准源输出的变化没有太大影响。综上所述,必须设计出性能优秀的带隙基准源,才能保证整个电路拥有高性能。带隙基准电源它也是一种对工作温度不是很敏感的精准参考电源。将具有负温度系数的三极管基-射极电压(VBE)以恰当的比例与具有正温度系数的电压叠加在一起,则可以获得一个零温度系数的电压输出。在标准带隙基准电路中,我们可以以调整电阻的比例的方法来产生合适的比例系数。在标准的CMOS工艺中,电阻模型的精确度不是很高,这就需要通过激光调修来保证它的精度,同时电阻会占用较大的芯片面积,导致生产成本高,效率低。而本论文中运用工作在亚阈值的MOS管则使电路结构简单、低功耗,并且性能可以与传统基准媲美。本文首先简要介绍了基准电压源的国内外研究历史及研究近况,介绍了基准电压源的技术指标,阐述了基准电压源的原理。其次,介绍了传统的带隙基准的原理以及设计,在此基础上,基于TSMC 0.35μm工艺,按照设计要求实现了一种低功耗基准电压源。后用Cadence设计电路并且仿真,结果显示,电路基本达到了设计要求,具备良好的性能指标。45923
毕业论文关键词:带隙基准;低功耗;温度系数;基准电压
ABSTRACT
Reference voltage circuit in integrated circuit design is an indispensable unit module, it is widely used in all kinds of analog integrated circuits and hybrid integrated circuit, such as A/D and D/A converters, etc. As the feature size of integrated circuits smaller and smaller, the chip power supply voltage and power consumption are reduced, so to reference source is more and more high performance requirements. The temperature stability of the reference source and power supply rejection ratio (PSRR) parameters such as voltage will affect the performance of the whole circuit system. At the same time, along with the advance of mixed-signal integrated circuit development, to reference the source of some parameters such as temperature coefficient, low power design and power supply rejection ratio (PSRR) have put forward higher requirements. These requirements will make the design of the band gap reference source face a bigger challenge. Band gap reference source in the power management chip has an important position, it is the most basic, the most critical unit module, the high-performance bandgap reference source is the key of the research. The so-called high-performance bandgap reference source, it includes many aspects of performance indicators. For example, low temperature coefficient of the band gap reference source, the band gap reference source make the output of the reference source along with the change of temperature is small; And high power supply rejection ratio of reference source, it can let the band gap reference source has a stronger anti-interference ability; Power regulation small band gap reference source, the reference source as the change of supply voltage its smaller influence on the change of the reference source output. Above all, have to design a high performance band gap reference source, to ensure the good performance of the whole circuit. Band gap reference power supply it is also a kind of sensitive to temperature is not very accurate reference power source. Key will have a negative temperature coefficient of triode emitter voltage in proper proportion and has the positive temperature coefficient voltage added together, you can get a zero temperature coefficient of the voltage output. In conventional bandgap reference circuit, we can adjust the proportion of resistance to generate the appropriate proportion coefficient. In standard CMOS process, the resistance model accuracy is not so high, this needs through laser tuned to ensure its accuracy, resistance at the same time it would take a large chip area, leading to a high production cost and low efficiency. And use this design work in the threshold of the MOS tube makes the circuit structure is simple, low power consumption, and the performance can be comparable to the traditional benchmark. This paper first summarizes the research history and research status of the benchmark voltage source, the technical index of the reference voltage source is introduced, expounds the theoretical foundation of the reference voltage source. Secondly, this paper introduces the principle of conventional bandgap reference, and design, on this basis, based on TSMC 0.35 mu m process, in accordance with the design requirements for class implements a low-power bandgap reference voltage source. After using Cadence, circuit design and simulation results show that the basic circuit meet the design requirements, have good performance. 低功耗电压基准源的设计:http://www.youerw.com/tongxin/lunwen_47541.html