不同结构CMOS运算放大器电路的电离辐射效应

介绍了在相同工艺条件下,N沟和P沟输入两种不同结构CMOS运算放大器电路的电离辐照响应规律及各子电路对电特性的影响情况.结果表明:由辐照感生的氧化物电荷引起的N沟镜像负载的不对称是导致P沟输入运放电特性衰降的主要机制;而由氧化物电荷和界面态引起的N沟差分对的漏电增大则是造成N沟输入运放电路性能变差的主要原因.     

不同注F剂量与CMOS运放电路辐照损伤的相关性

在不同注F剂量条件下,对P沟和N沟两种不同差分对输入CMOS运放电路的电离辐照响应进行了研究.分析比较了注F和未注F运放电路电离辐照响应之间的差异.结果表明,在栅场介质注入适量的F,可有效抑制辐照感生的氧化物电荷尤其是界面态的增长,从而提高CMOS运放电路的抗辐照特性.     

不同注F剂量与CMOS运放电路辐照损伤的相关性

在不同注F剂量条件下,对P沟和N沟两种不同差分对输入CMOS运放电路的电离辐照响应进行了研究.分析比较了注F和未注F运放电路电离辐照响应之间的差异.结果表明,在栅场介质注入适量的F,可有效抑制辐照感生的氧化物电荷尤其是界面态的增长,从而提高CMOS运放电路的抗辐照特性.     

栅氧化方式对N沟输入CMOS运算放大器电离辐射效应的影响

介绍了干氧和氢氧合成两种不同栅氧化方式下制作的 N沟输入 CMOS运算放大器电路的电离辐照响应特征 .并通过对电路内部单管特性损伤分析的比较 ,探讨了引起两者辐照敏感性差异的原因 .结果显示 ,氢氧合成工艺比干氧工艺损伤明显的原因 ,是因为 H的引入产生了更多的界面态 ,从而使其单管的跨导明显下降所致 .这表明 ,抑制辐照感生氧化物电荷尤其是界面态的增长 ,对提高电路的抗辐射特性至关重要 .     

栅氧化方式对N沟输入CMOS运算放大器电离辐射效应的影响

介绍了干氧和氢氧合成两种不同栅氧化方式下制作的N沟输入CMOS运算放大器电路的电离辐照响应特征.并通过对电路内部单管特性损伤分析的比较,探讨了引起两者辐照敏感性差异的原因.结果显示,氢氧合成工艺比干氧工艺损伤明显的原因,是因为H的引入产生了更多的界面态,从而使其单管的跨导明显下降所致.这表明,抑制辐照感生氧化物电荷尤其是界面态的增长,对提高电路的抗辐射特性至关重要.     

CMOS运算放大器的辐照和退火行为

介绍了CMOS运算放大器电路经电离辐照后,在不同偏置及不同退火温度下,运放整体性能参数、电路内部单管特性及功能单元电路的节点电流、电压的变化规律,分析了引起运放辐照后继续损伤退化的基本原因.结果显示,运放电路辐照后的退火行为与偏置及温度均有较大的依赖关系,而这种关系与辐照感生的氧化物电荷和Si/SiO2界面态密度的增长与退火直接相关.     

CMOS运算放大器的辐照和退火行为

介绍了CMOS运算放大器电路经电离辐照后 ,在不同偏置及不同退火温度下 ,运放整体性能参数、电路内部单管特性及功能单元电路的节点电流、电压的变化规律 ,分析了引起运放辐照后继续损伤退化的基本原因 .结果显示 ,运放电路辐照后的退火行为与偏置及温度均有较大的依赖关系 ,而这种关系与辐照感生的氧化物电荷和Si/SiO2 界面态密度的增长与退火直接相关     

CMOS运算放大器电离辐照的后损伤效应

介绍了CMOS运算放大器经60CoY辐照及辐照后在不同温度下随时间变化的实验结果，并通过对差分对单管特性和电路内部各单元电路损伤退化的分析，探讨了引起电路“后损伤”效应的原因。结果表明，由辐照感生的氧化物电荷和界面态的消长及差分对管的不匹配，是造成电路继续损伤劣化的根本原因。对于CMOS运算放大器电路，在抑制辐照感生的氧化物电荷和界面态增长的同时，改善电路间的对称性和匹配性，对提高电路的抗辐射能力是至关重要的。     

注氟加固PMOSFET的电离辐射响应与时间退火效应

研究了注F加固PMOSFET的总剂量辐照响应特性和辐照后由氧化物电荷、界面态变化引起的阈电压漂移与时间、温度、偏置等退火条件的关系，发现一定退火条件下注F加固PMOSFET由于界面态密度、特别是氧化物电荷密度继续增加，使得电路在电高辐照后继续损伤，探讨了加速MOS器件电离辐照感生界面态生长的方法。     

两种不同工艺CMOS运算放大器的电离辐照响应特性

研究了干氧和氢氧合成两种不同工艺 CMOS运算放大器电路的电离辐照响应特征和变化规律。结果显示 ,虽然对单管特性而言 ,干氧工艺具有较强的抑制辐射感生氧化物电荷和界面态增长的能力 ,但由于在辐照过程中氧化物电荷的形成改变了电路的对称性 ,因而对电路造成比氢氧合成工艺更大的损伤。表明 ,适当的界面态的引入 ,有利于增加负载电流镜的饱和工作范围 ,从而降低电路的辐射敏感性。     

A multiplexed switched capacitor filter bank

A technique is introduced which allows several integrator capacitors to be multiplexed onto a single operational amplifier. As a result, the op amp can be shared by several switched capacitor filter channels, drastically reducing the number of op amps required for filter banks. Twenty second-order filters have been implemented in a circuit using only two op amps and 2.5 mm/SUP 2/. The design of this system is presented and its performance is discussed. Some loss of signal energy is shown to occur during the multiplexing operations, which reduces filter Q. Causes of this charge loss are described, and its effects on performance are modeled. The design of the op amp used is presented, which incorporates a new system of input stage biasing and differential to single-ended conversion, as well as other features.     

一款应用于GPS接收机的抗失配零中频混频器

为了解决单正交零中频混频器I/Q失配造成的影响,提高自身镜像抑制能力。基于电位混频原理采用CMOS 0.18μm工艺设计出一款工作在1.575 42GHz双正交结构的抗失调零中频混频器,通过添加四个电容构成MOSFET-C低通滤波器以及两个在低频段工作的运放构成的输出放大级,射频输入信号能够得到有效处理。测试结果表明该结构在镜像抑制能力上比传统结构改善了6dB左右,电路采用1.8V供电电压,功耗为3.6mW,1MHz频点附近的噪声系数约为17dB,1dB输入压缩点为14.6dBm。     

An 8-bit 100-MS/s pipelined ADC without dedicated sample-and-hold amplifier

An 8-b 100-MS/s pipelined analog-to-digital converter(ADC) is presented.Without the dedicated sample-and -hold amplifier(SHA),it achieves figure-of-merit and area 21%and 12%less than the conventional ADC with the dedicated SHA,respectively.The closed-loop bandwidth of op amps in multiplying DAC is modeled,providing guidelines for power optimization.The theory is well supported by transistor level simulations.A 0.18-μm 1P6M CMOS process was used to integrate the ADCs,and the measured results show that the...     

Simple technique for op amp continuous-time 1 V supply operation

A simple scheme for achieving continuous-time low-voltage operation of op amps is discussed. The scheme involves placing a floating battery in series with one of the op amp input terminals. Simulations and experimental results are presented that verify the proposed scheme with the example of a CMOS op amp that operates from a single 1 V supply and with 0.8 V signal swing     

Current mode instrumentation amplifier with rail-to-rail input and output

This paper presents the results from an investigation on the implementation of Current Mode Instrumentation Amplifiers (CMIAs) with rail-to-rail operational amplifiers (op amp) with a gm control circuit. The objective of employing rail-to-rail op amps in the implementation of a CMIA is the improvement of the common-mode operation range. The enhancement of the input common mode range (ICMR) is obtained using op amps with a rail-to-rail input stage followed by a cascode-based output stage. A prototype of the CMIA was implemented in standard 0.6 μm XFAB CMOS technology. Test results showed that the CMIA common mode range was extended but with moderated CMRR. To minimize this issue the amplifier was re-designed and sent to fabrication. Simulations with the components variations included were performed and showed the enhancement of the CMRR can be expected.     

Changing technology-banish the 741! [op amp]

Pick up a current electronics text and you're likely to find the 741 op amp not only used, but also showcased. It's the op amp of choice for lab experiments, treatment of innards, etc. This is truly amazing when you consider that the 741 is nearly 30 years old! Of course op amps should be presented they can be used to implement a remarkable range of circuit functions. An inexpensive op amp can give near-ideal performance in certain practical applications. Getting something to work is infectious-the first op amps gave a whole generation the opportunity to build analog functions that really worked. But, like all technologies, op amp development never ceased; there have been some serious developments over the last 30 years!     

Design techniques for cascoded CMOS op amps with improved PSRR and common-mode input range

Internally compensated CMOS op amps have been widely used in sampled-analog signal processing applications over the past several years. However, the popular two-stage op amp suffers from poor AC power supply rejection to one of the power rails. Two circuits are presented that overcome the power-supply rejection ratio (PSRR) problems of the earlier amplifier: one for virtual ground applications such as switched-capacitor integrators, the other for buffer applications requiring wide common-mode input range. Small signal analysis is developed for the open-loop and PSRR responses of the two amplifiers. In addition, design guidelines are suggested and test results are presented.     

高性能结型场效应对管及其在ASIC中的应用

采用结型场效应管作为输入级的专用集成电路,一般都具有高速宽带以及高输入阻抗的特点。场效应管与双极型器件相结合,已成为新型专用型集成运算放大器的主要发展方向之一。国内在这些专用集成电路的研制工作中所面临的主要困难,是高耐压高频结型场效应对管的工艺制作。本文在介绍高性能结型场效应对管在ASIC中的应用及其工艺试验情况。     

Macromodeling of integrated circuit operational amplifiers

A macromodel has been developed for integrated circuit (IC) op amps which provides an excellent pin-for-pin representation. The model elements are those which are common to most circuit simulators. The macromodel is a factor of more than six times less complex than the original circuit, and provides simulated circuit responses that have run times which are an order of magnitude faster and less costly in comparison to modeling the op amp at the electronic device level. Expressions for the values of the elements of the macromodel are developed starting from values of typical response characteristics of the op amp. Examples are given for three representative op amps. In addition, the performance of the macromodel in linear and nonlinear systems is presented. For comparison, the simulated circuit performance when modeling at the device level is also demonstrated.     

A dual current feedback op amp in CMOS technology

A CMOS circuit configuration implementing a current feedback or transimpedance op amp (CFB op amp) is presented. The architecture of the circuit is derived from similar bipolar CFB op amps. The properties of the CMOS implementation are similar to those of its bipolar counterparts, i.e., a high slew rate and a bandwidth which is independent of the closed-loop gain when the op amp is used with current feedback. Further, it is shown how two CFB op amps can be connected to achieve a non-slew-rate-limited voltage-mode op amp.