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Laser Telemetric System
Published in Stephan D. Murphy, In-Process Measurement and Control, 2020
Frank C. Demarest, James Soobitsky, Carl A. Zanoni
Signal distortion usually falls into two categories, slew rate limiting and group delay distortion. Slew rate limiting occurs when the signal changes more rapidly than the amplifier can follow. This is distinctly different from bandwidth limitation and may be recognized by the fact that rising and falling edges of the signal have constant slope rather than smooth curves. Group delay is defined as the derivative of phase of the transfer function. Group delay distortion occurs when some frequency components of the signal are delayed more than others as they pass through the electronics. When the scanned laser beam is focused to a smaller spot in the measurement region, the line of sharpest focus is slightly curved. Therefore, the frequency spectrum produced by one edge of the object being measured may be slightly different from the spectrum produced by the other edge. If some frequencies are delayed more than others in the electronics, an apparent measurement error may occur.
Measurement of system parameters
Published in Geoff Lewis, Communications Technology Handbook, 2013
Slew rate limiting. The slew rate for an amplifier is defined as the rate of change of the output voltage under large signal conditions. If this rate is exceeded by too large an input signal, then the output becomes distorted. Because this is related to the amplifier rise time, the slew rate is also related to the amplifier bandwidth. The relationship being given by slew rate = 2πfhVout(max) where fh is the upper 3 dB cut-off frequency. Testing is carried out using a high frequency square wave as input and measuring the slopes of the output signal relative to time, for both leading and trailing edges. Slew rate is then quoted for the slowest value.
Force-System Resultants and Equilibrium
Published in Richard C. Dorf, The Engineering Handbook, 2018
The output voltage swing over which the linear model is valid is limited by the power supply voltage(s) and the op-amp architecture. The peak output current is limited by internal bias currents and/or protection circuitry. The output slew rate, which is the maximum slope of the output signal before distortion occurs, is limited by op-amp internal currents and capacitances. The common-mode input voltage range is the range of the common-mode (or average) input voltage, which is v++v-/2, for which the linear op-amp model is valid. In Figure 115.2, it is important that ground be within this range since v++v-/2≈0 in this circuit. In Figure 115.3,vIN must stay in the common-mode input range since v++v-/2≈vIN.
DTMOS Based Low Power Adaptively Biased Fully Differential Transconductance Amplifier with Enhanced Slew-Rate and its Filter Application
Published in IETE Journal of Research, 2023
Mihika Mahendra, Shweta Kumari, Maneesha Gupta
Slew-rate decides how fast the amplifier’s output voltage changes from one level to another level with time. For the high-speed operation of the OTA, this parameter must have a high value. Although in a multi-stage OTA, this parameter gets limited by the slowest stage of the OTA. The necessary amount of biasing current required for charging or discharging a capacitor in this stage is responsible for it. This parameter is considerable as it determines the maximum frequency and the settling time of the output signal. If the biasing current through the proposed circuit indicated by , then the slew-rate (SR) of the OTA can be approximated by:
Development of Siddha Varmam energy measurement system for monitoring human health conditions
Published in Journal of Medical Engineering & Technology, 2021
R. Rixon Raj, P. T. V. Bhuvaneswari
The performance metrics include energy, maximum amplitude, minimum amplitude, gain, peak to peak amplitude, mean, median, rms, transition high, transition low, transition amplitude, rise time and slew rate.Energy: The Signal Energy in the discrete time signal x(n) are represented by Equations (1) and (2). where E denotes the Energy and Ec is the Energy in Calories.Peak to Peak Voltage: It is the voltage considered from the trough of the waveform till the crest. It is computed using Equation (3). where Vpeak to peak denotes the peak to peak voltage and Vpeak is the peak value.RMS: It is the Root Mean Square value of the signal. For a digitised signal it is calculated by squaring each value, finding the arithmetic mean of those squared values and taking square root of the result. It represents the average power of a signal as mentioned in Equation (4). where VRMS is the RMS voltage and Vpeak is the peak value.Slew Rate: It is defined as the rate of change of voltage per unit time. It is calculated using Equation (5). where f is frequency and v is voltage.