The Experts below are selected from a list of 42 Experts worldwide ranked by ideXlab platform
Ron Mancini - One of the best experts on this subject based on the ideXlab platform.
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develOpment of the Ideal Op Amp equations
Op Amps for Everyone (Third Edition), 2009Co-Authors: Ron ManciniAbstract:This chapter discusses some Ideal Op Amp equations. There is no such thing as an Ideal Op Amp, but present day Op Amps come so close to Ideal that Ideal Op Amp analysis approaches actual analysis. Op Amps depart from the Ideal in two ways. First, dc parameters such as input offset voltage are large enough to cause departure from the Ideal, which assumes that input offset voltage is zero. Second, ac parameters such as gain are a function of frequency, so they go from large values at dc to small values at high frequencies. Although the Ideal Op Amp analysis makes use of perfect parameters, the analysis is often valid because some Op Amps approach perfection. In addition, when working at low frequencies, several kHz, the Ideal Op Amp analysis produces accurate answers. Several assumptions have to be made before the Ideal Op Amp analysis can proceed. First, it has to be assumed that the current flow into the input leads of the Op Amp is zero. Second, the Op Amp gain is assumed to be infinite, hence it drives the output voltage to any value to satisfy the input conditions. Also, implicit in the infinite gain assumption is the need for zero input signal. Finally, one has to assume that the output impedance of the Ideal Op Amp is zero.
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chapter 3 develOpment of the Ideal Op Amp equations
Op Amps for Everyone (Second Edition)#R##N#Design Reference, 2003Co-Authors: Ron ManciniAbstract:Publisher Summary This chapter discusses some Ideal Op Amp equations. There is no such thing as an Ideal Op Amp, but present day Op Amps come so close to Ideal that Ideal Op Amp analysis approaches actual analysis. Op Amps depart from the Ideal in two ways. First, dc parameters such as input offset voltage are large enough to cause departure from the Ideal, which assumes that input offset voltage is zero. Second, ac parameters such as gain are a function of frequency, so they go from large values at dc to small values at high frequencies. Although the Ideal Op Amp analysis makes use of perfect parameters, the analysis is often valid because some Op Amps approach perfection. In addition, when working at low frequencies, several kHz, the Ideal Op Amp analysis produces accurate answers. Several assumptions have to be made before the Ideal Op Amp analysis can proceed. First, it has to be assumed that the current flow into the input leads of the Op Amp is zero. Second, the Op Amp gain is assumed to be infinite, hence it drives the output voltage to any value to satisfy the input conditions. Also, implicit in the infinite gain assumption is the need for zero input signal. Finally, one has to assume that the output impedance of the Ideal Op Amp is zero.
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develOpment of the non Ideal Op Amp equations
Op Amps for Everyone (Second Edition)#R##N#Design Reference, 2003Co-Authors: Ron ManciniAbstract:This chapter describes the equations that illustrate the effects of the gain changes. It begins with a review of the basic canonical feedback system stability because the Op Amp equations are develOped using the same techniques. Amplifiers are built with active components such as transistors. Pertinent transistor parameters like transistor gain are subject to drift and initial inaccuracies from many sources, so Amplifiers built from these components are subject to drift and inaccuracies which can be minimized or eliminated by using negative feedback. The Op Amp circuit configuration employs feedback to make the transfer equation of the circuit independent of the Amplifier parameters (well almost), and while doing this, the circuit transfer function is made dependent on external passive components. The external passive components can be purchased to meet almost any drift or accuracy specification; only the cost and size of the passive components limit their use. Noninternally compensated or externally compensated Op Amps are unstable without the addition of external stabilizing components. Compensation is achieved by adding external components that modify the circuit transfer function, so that it becomes unconditionally stable.
Vladimir Kornijcuk - One of the best experts on this subject based on the ideXlab platform.
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relaxation oscillator realized artificial electronic neurons their responses and noise
Nanoscale, 2016Co-Authors: Vladimir Kornijcuk, Jun Yeong Seok, Cheol Seong Hwang, Doo Seok JeongAbstract:A proof-of-concept relaxation oscillator-based leaky integrate-and-fire (ROLIF) neuron circuit is realized by using an amorphous chalcogenide-based threshold switch and non-Ideal Operational Amplifier (Op-Amp). The prOposed ROLIF neuron offers biologically plausible features such as analog-type encoding, signal Amplification, unidirectional synaptic transmission, and Poisson noise. The synaptic transmission between pre- and postsynaptic neurons is achieved through a passive synapse (simple resistor). The synaptic resistor coupled to the non-Ideal Op-Amp realizes excitatory postsynaptic potential (EPSP) evolution that evokes postsynaptic neuron spiking. In an attempt to generalize our prOposed model, we theoretically examine ROLIF neuron circuits adOpting different non-Ideal Op-Amps having different gains and slew rates. The simulation results indicate the importance of gain in postsynaptic neuron spiking, irrespective of the slew rate (as long as the rate exceeds a particular value), providing the basis for the ROLIF neuron circuit design. Eventually, the behavior of a postsynaptic neuron in connection to multiple presynaptic neurons via synapses is highlighted in terms of EPSP evolution amid simultaneously incident asynchronous presynaptic spikes, which in fact reveals an important role of the random noise in spatial integration.
Doo Seok Jeong - One of the best experts on this subject based on the ideXlab platform.
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relaxation oscillator realized artificial electronic neurons their responses and noise
Nanoscale, 2016Co-Authors: Vladimir Kornijcuk, Jun Yeong Seok, Cheol Seong Hwang, Doo Seok JeongAbstract:A proof-of-concept relaxation oscillator-based leaky integrate-and-fire (ROLIF) neuron circuit is realized by using an amorphous chalcogenide-based threshold switch and non-Ideal Operational Amplifier (Op-Amp). The prOposed ROLIF neuron offers biologically plausible features such as analog-type encoding, signal Amplification, unidirectional synaptic transmission, and Poisson noise. The synaptic transmission between pre- and postsynaptic neurons is achieved through a passive synapse (simple resistor). The synaptic resistor coupled to the non-Ideal Op-Amp realizes excitatory postsynaptic potential (EPSP) evolution that evokes postsynaptic neuron spiking. In an attempt to generalize our prOposed model, we theoretically examine ROLIF neuron circuits adOpting different non-Ideal Op-Amps having different gains and slew rates. The simulation results indicate the importance of gain in postsynaptic neuron spiking, irrespective of the slew rate (as long as the rate exceeds a particular value), providing the basis for the ROLIF neuron circuit design. Eventually, the behavior of a postsynaptic neuron in connection to multiple presynaptic neurons via synapses is highlighted in terms of EPSP evolution amid simultaneously incident asynchronous presynaptic spikes, which in fact reveals an important role of the random noise in spatial integration.
Jun Yeong Seok - One of the best experts on this subject based on the ideXlab platform.
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relaxation oscillator realized artificial electronic neurons their responses and noise
Nanoscale, 2016Co-Authors: Vladimir Kornijcuk, Jun Yeong Seok, Cheol Seong Hwang, Doo Seok JeongAbstract:A proof-of-concept relaxation oscillator-based leaky integrate-and-fire (ROLIF) neuron circuit is realized by using an amorphous chalcogenide-based threshold switch and non-Ideal Operational Amplifier (Op-Amp). The prOposed ROLIF neuron offers biologically plausible features such as analog-type encoding, signal Amplification, unidirectional synaptic transmission, and Poisson noise. The synaptic transmission between pre- and postsynaptic neurons is achieved through a passive synapse (simple resistor). The synaptic resistor coupled to the non-Ideal Op-Amp realizes excitatory postsynaptic potential (EPSP) evolution that evokes postsynaptic neuron spiking. In an attempt to generalize our prOposed model, we theoretically examine ROLIF neuron circuits adOpting different non-Ideal Op-Amps having different gains and slew rates. The simulation results indicate the importance of gain in postsynaptic neuron spiking, irrespective of the slew rate (as long as the rate exceeds a particular value), providing the basis for the ROLIF neuron circuit design. Eventually, the behavior of a postsynaptic neuron in connection to multiple presynaptic neurons via synapses is highlighted in terms of EPSP evolution amid simultaneously incident asynchronous presynaptic spikes, which in fact reveals an important role of the random noise in spatial integration.
Bruce Carter - One of the best experts on this subject based on the ideXlab platform.
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chapter 2 develOpment of the Ideal Op Amp equations
Op Amps for Everyone (Fifth Edition), 2018Co-Authors: Bruce CarterAbstract:Op Amp circuits are designed using simple electronics rules that the designer must be familiar with. It is a device that depends on the use of negative feedback to Operate. Many circuits can be designed using the Ideal Op Amp model, but the real world will affect the results. The simplest circuits are inverting and noninverting gain, adders, and differential, although more complex feedback networks are not only possible but commonplace.
