High-Performance CMOS Current Mirrors: Application to Linear Voltage-to-Current Converter Used for Two-Stage Operational Amplifier

This paper presents two schemes of high performance CMOS current mirror, one of them is used for operational tran-sconductance amplifier (OTA) in analog VLSI systems. The linearity, output impedance, bandwidth and accuracy are the most parameters to determine the performance of the current mirror. Here a comparison of two architectures based on same architecture of the amplifier is presented. This comparison includes: linearity, output impedance, bandwidth and accuracy. These two circuits are validated with simulation in technology AMS 0.35 μm. An operational amplifier based on the adapted current mirror is proposed. Its frequency analysis with large bandwidth is validated with the same technology.

A low-voltage sense amplifier with two-stage operational amplifier clamping for flash memory

A low-voltage sense amplifier with reference current generator utilizing two-stage operational amplifier clamp structure for flash memory is presented in this paper,capable of operating with minimum supply voltage at1 V.A new reference current generation circuit composed of a reference cell and a two-stage operational amplifier clamping the drain pole of the reference cell is used to generate the reference current,which avoids the threshold limitation caused by current mirror transistor in the traditional sense amplifier.A novel reference voltage generation circuit using dummy bit-line structure without pull-down current is also adopted,which not only improves the sense window enhancing read precision but also saves power consumption.The sense amplifier was implemented in a flash realized in 90 run flash technology.Experimental results show the access time is 14.7 ns with power supply of 1.2 V and slow corner at 125℃.

A low-powerlow-voltage slew-rate enhancement circuit for two-stage operational amplifiers

A novel circuit is presented in order to enhance the slew rate of two-stage operational amplifiers. The enhancer utilizes the class-AB input stage to improve current efficiency, while it works on an open loop with regard to the enhanced amplifier so that it has no effect on the stability of the amplifier. During the slewing period, the enhancer detects input differential voltage of the amplifier, and produces external enhancement currents for the amplifier, driving load capacitors to charge/discharge faster. Simulation results show that, fora large input step, the enhancerreduces settling time by nearly 50%. When the circuit is employed in a sample-and-hold circuit, it greatly improves the spur-free dynamic range by 44.6 dB and the total harmonic distortion by 43.9 dB. The proposed circuit is very suitable to operate under a low voltage （1.2 V or below） with a standby current of 200 μA.

Optimization Design of Two-Stage Operational Amplifier with Frequency Compensation via Geometric Programming

An optimization design technique to obtain global solution for a two-stage operational amplifier(op-amp) with frequency compensation is presented.This frequency compensation technique can adjust the equivalent resistance to guarantee that the phase margin is stable even though circumstance temperature varies.Geometric programming is used to optimize the component values and transistor dimensions.It is used in this analog integrated circuit design to calculate these parameters automatically.This globally optimal amplifier obtains minimum power while other specifications are fulfilled.

Active Damping of Milling Vibration Using Operational Amplifier Circuit

The problem of chatter vibration is associated with adverse consequences that often lead to tool impairment and poor surface finished in a workpiece, and thus, controlling or suppressing chatter vibrations is of great significance to improve machining quality. In this paper, a workpiece and an actuator dynamics are considered in modeling and controller design. A proportional-integral controller(PI) is presented to control and actively damp the chatter vibration of a workpiece in the milling process. The controller is chosen on the basis of its highly stable output and a smaller amount of steady-state error. The controller is realized using analog operational amplifier circuit. The work has contributed to planning a novel approach that addresses the problem of chatter vibration in spite of technical hitches in modeling and controller design. The method can also lead to considerable reduction in vibrations and can be beneficial in industries in term of cost reduction and energy saving. The application of this method is verified using active damping device actuator(ADD) in the milling of steel.

DESIGN AND ANALYSIS OF INTEGRATED OPERATIONAL AMPLIFIER XD1531 WITH LOW NOISE AT LOW FREQUENCIES

Principles of design are described for the low frequency integrated operationalamplifler XD1531 with low noise. The procedures of design of both the circuit structure and the tran-sistor shape are considered. The first stage of the circuit is designed with the methods of low noise atlow frequencies. The measures which decrease noises, especially, the 1/f noise originating .from thesemiconductor surface state and defects, are used for the transistor structure design. With analysisand comparison to products here and abroad in characteristics, it is shown that XD1531 has a lowernoise index at low frequencies than others, and the effectiveness of design methods for bringing lownoises have been demonstrated.

A VERSATILE CURRENT-MODE BIQUAD USING OPERATIONAL AMPLIFIERS

A versatile current-mode biquadratic filter using three operational amplifiers and nine passive elements is proposed. By suitably choosing the output branch, lowpass, bandpass, highpass, bandstop and allpass transfer functions are realized simultaneously without changing the circuit configuration and elements. Two circuits, one is for low frequency application and the other for high frequency, are proposed. The center frequency, quality factor and gain constants of the circuit can be tuned independently. Simulated results show that the circuits work successfully.

Symbolic Macromodeling for Statistical Simulation of Operational Amplifiers

Symbolic circuit simulator is traditionally applied to the small-signal analysis of analog circuits. This paper establishes a symbolic behavioral macromodeling method applicable to both small-signal and large-signal analysis of general two-stage operational amplifiers （op-amps）. The proposed method creates a two-pole parametric macromodel whose parameters are analytical functions of the circuit element parameters generated by a symbolic circuit simulator. A moment matching technique is used in deriving the analytical model parameter. The created parametric behavioral model can be used for op-amps performance simulation in both frequency and time domains. In particular, the parametric models are highly suited for fast statistical simulation of op-amps in the time-domain. Experiment results show that the statistical distributions of the op-amp slew and settling time characterized by the proposed model agree well with the transistor-level results in addition to achieving significant speedup.

Low-Power Operational Amplifier for Real-Time Signal Processing System of Micro Air Vehicle

A low-power complementary metal oxide semiconductor（CMOS） operational amplifier （op-amp） for real-time signal processing of micro air vehicle （MAV） is designed in this paper.Traditional folded cascode architecture with positive channel metal oxide semiconductor（PMOS） differential input transistors and sub-threshold technology are applied under the low supply voltage.Simulation results show that this amplifier has significantly low power,while maintaining almost the same gain,bandwidth and other key performances.The power required is only 0.12 mW,which is applicable to low-power and low-voltage real-time signal acquisition and processing system.

Efficient Slew-Rate Enhanced Operational Transconductance Amplifier

Today, along with the prevalent use of portable equipment, wireless, and other battery powered systems, the demand for amplifiers with a high gain-bandwidth product（GBW）, slew rate（SR）, and at the same time very low static power dissipation is growing. In this work, an operational transconductance amplifier（OTA） with an enhanced SR is proposed. By inserting a sensing resistor in the input port of the current mirror in the OTA, the voltage drop across the resistor is converted into an output current containing a term in proportion to the square of the voltage, and then the SR of the proposed OTA is significantly enhanced and the current dissipation can be reduced. The proposed OTA is designed and simulated with a 0.5μm complementary metal oxide semiconductor（CMOS） process. The simulation results show that the SR is 4.54V/μs, increased by 8.25 times than that of the conventional design, while the current dissipation is only 87.3%.

Modeling operation amplifier based on VHDL-AMS for TID effect

A model of the operational amplifier based on VHDL-AMS is proposed. According to needs of simulating the total ionizing dose(TID) radiation effect, parameters of operational amplifier are taken into account when the performance is specified. The operational amplifier model used for the TID radiation effect simulation is completed after verifying each modeled parameter. And a parameter for describing the external environment is introduced to make the model combined with TID. Finally, an example is used to illustrate the TID effect on the operational amplifier of MC14573, proving the validity of the model.

Investigation of the risk factors associated with early mortality of the rapid two-stage arterial switch operation

Objective To investigate the risk factors associated with early mortality of the rapid two-stage arerial switch operation,which has a significantly higher overall mortality than that of ASO procedure for D-TGA with an intact ventricular septum. Methods The data we reviewed involving patients who underwent rapid two-stage switch operations from September,2002 to September,2007 in our center,13 patients were male and 8

THE DESIGN OF BALANCED AMPLIFIER BASED ON COMMON-MODE FEEDBACK

The balanced operational amplifier including its merits and designing methods is discussed by comparing its performance to a conventional differential output amplifier when used in a single balanced stage. A balanced OTA circuit design is also presented.

MicroAmplifier^(TM)系列运算放大器的特性及应用

扼要介绍 MicroAmplifier^(TM)系列运算放大器的特性、封装型式及应用技术。

Fuzzy System Design Using Current Amplifier for 20 nm CMOS Technology

In the recent decade,different researchers have performed hardware implementation for different applications covering various areas of experts.In this research paper,a novel analog design and implementation of different steps of fuzzy systems with current differencing buffered amplifier(CDBA)are proposed with a compact structure that can be used in many signal processing applications.The proposed circuits are capable of wide input current range,simple structure,and are highly linear.Different electrical parameters were compared for the proposed fuzzy system when using different membership functions.The novelty of this paper lies in the electronic implementation of different steps for realizing a fuzzy system using current amplifiers.When the power supply voltage of CDBA is 2V,it results in 155mW,power dissipation;4.615KΩ,input resistance;366KΩ,output resistances;and 189.09 dB,common-mode rejection ratio.A 155.519 dB,voltage gain,and 0.76V/μs,the slew rate is analyzed when the power supply voltage of CDBAis 3V.The fuzzy system is realized in 20nm CMOS technology and investigated with an output signal of high precision and high speed,illustrating that it is suitable for realtime applications.In this research paper,a consequence of feedback resistance on the adder circuit and the defuzzified circuit is also analyzed and the best results are obtained using 100K resistance.The structure has a low hardware complexity leading to a low delay and a rather high quality.

A 0.4 V Bulk-Driven Amplifier for Low-Power Data Converter Applications

This paper presents the design of an ultra low-voltage (ULV) pseudo operational transconductance amplifier (P-OTA) that is able to operate with a single supply voltage as low as 0.4 V. The proposed circuit is based on the bulk-driven technique and use of cross-coupled self-cascode pairs that boosts the differential DC gain. The stability condition of this structure for the DC gain is considered by definition of two coefficients to cancel out a controllable percentage of the denominator. This expression for stability condition yield optimized value for the DC gain. Also, as the principle of operation of the proposed technique relies on matching conditions, Monte Carlo analyzes are considered to study of the behavior of the proposed circuit against mismatches. The designed P-OTA have a DC gain of 64 dB, 212 KHz unity gain bandwidth, 57phase margin that is loaded by 10 pF differential capacitive loads, while consume only 16 μW. Eventually, from the proposed P-OTA, a low-power Sample and Hold (S/H) circuit with sampling frequency of 10 KS/s has been designed and simulated. The correct functionality for this configuration is verified from –30℃ to 70℃. The simulated data presented is obtained using the HSPICE Environment and is valid for the 90 nm triple-well CMOS process.

Energy-Level of Some Singular Harmonic Oscillators and Parametric Amplifiers with Singular Potential Derived via IEO Method

我们采用不变的 eigen 操作员(IEO ) 发现 N 身体单个振荡器的 Hamiltonians 的 invarianteigen 操作员然后导出他们的精力的方法豁开。有单个潜力的参量的放大器的 TheHamiltonians 也这样被讨论。

Optimization and design of inter-stage amplifier with wide output swing,high speed and high accuracy

To satisfy the design requirements of analog-to-digital converter(ADC)of high speed sampling system in an infrared focal plane array tester with 1024×1024 pixels,a first inter-stage amplifier of 12-bit 40-Msample/s pipelined ADC was designed with 0.35 μm CMOS technology.On the basis of traditional two-stage amplifier,the cross-coupled class AB output stage and cascode compensation were adopted to improve the output voltage swing and bandwidth.Power dissipation was optimized with math tools.Circuit and layout design were completed.Simulation results show that the designed amplifier has good performance of 95 dB dc gain,±2 V output voltage swing,190 MHz bandwidth and 63° phase margin with feedback factor 1/4,33 mW power dissipation and so on,which can meet the system requirements.