Beyond the primitive transistor, the operational amplifier (op amp) is the most basic building block for analog applications. Fundamental functions such as gain, load isolation, signal inversion, level shifting, adding and/or subtracting signals are easily implemented with an op amp. More complex circuits can also be implemented, such as the instrumentation amplifier, a current-to-voltage conve...

Nonideal factors which play a key role in performance and yield in high-precision applications of operational amplifiers are rigorously investigated. Of necessity, the combined effects of both deterministic and statistical parameters must be incorporated. The statistical characteristics of the common-mode rejection ratio and the offset of two-stage CMOS op-amps are investigated. The op-amp erro...

Two bulk-driven CMOS (Complementary Metal Oxide Semiconductor) operational amplifier (op-amp) designs for electrocardiogram (ECG) application are presented and compared in this paper. Both op-amps based on two-stage amplification, where differential input is the first stage, while additional DC gain second stage. Different compensation techniques were integrated each op-amp design. Standard Mil...

This p a p e r presents a low power, h i g h ga in and high CMRR ful ly differential ultra-wide bandwidth operational amplifier with wide dynamic range. The design uses two-stage gain, high swing common-mode feedback, ‘doublet-free’ pole-zero cancelation and gm–boosting techniques to increases the unity gain frequency. Design and implementation results for a 1.2GHz, 1.8V supply, fully different...

A third-order single-bit delta-sigma modulator is presented in this paper. An op-amp dynamic current biasing technique is used to improve the power-efficiency of the modulator. The voltage reference block is integrated with the delta-sigma modulator core to avoid the use of large off-chip bypass capacitors and to minimize pin numbers. It achieves 89.2 dB dynamic range over 10 kHz signal bandwid...

In this paper the current mode approach called “Current Conveyor (CCII+)” has been incorporated to design and simulate the circuit for producing two amplitude matched anti-phase sine waveforms which are frequently used in various communication and instrumentation systems. PSpice simulation has been used to depict the output waveforms. The power supply used is ±2.5 V which can be easily incorpor...

This paper describes an instrumentation amplifier (INA) with three operational amplifier (op amp) topology, for biomedical applications. To achieve low offset new circuit technique is achieved by adding NMOS transistor and two phase clock scheme with a frequency of 20 KHz. With the unity gain bandwidth of 92 KHz , the open loop gain of this instrumentation amplifier is found to be 50 dB and hav...

An architecture for low-power Σ∆ modulators suitable for high-resolution portable sensor systems is presented. The circuit uses a single operational amplifier to achieve a thirdorder noise shaping. The two-stage op-amp employs a boosting technique that increases by 5 the slew-rate. The circuit, simulated at the transistor level using a conventional 0.18-μm CMOS technology, obtains a peak SNDR o...

The Operational Transconductance Amplifier is a basic building blocks found in many analog circuits such as data converter’s (ADC& DAC) and Gm-c filters. The OTA is an amplifier whose differential input voltage produces an output current .Thus ,it is a voltage controlled current source(VCCS) whereas the Op-amp are voltage controlled voltage source(VCVS). There is usually an additional input for...

An automatic synthesis tool for CMOS op amps (OPASYN) has been developed. The program starts from one of a number of op amp circuits and proceeds to optimize various device sizes and bias currents to meet a given set of design specifications. Because it uses analytic circuit models in its inner optimization loop, it can search efficiently through a large part of the possible solution space. The...