Dynamic-range optimisation of second-order integrator-loop active filters

1996 ◽  
Author(s):  
P. Bowron
1974 ◽  
Vol 64 (1) ◽  
pp. 103-113 ◽  
Author(s):  
E. R. Kanasewich ◽  
W. P. Siewert ◽  
M. D. Burke ◽  
C. H. McCloughan ◽  
L. Ramsdell

abstract A wide-band, gain-ranging amplifier is described that may be used for recording data with a dynamic range of 60 db in each of three different levels, 12 db apart, so that we achieve an “effective” dynamic ±160-v analog or 84-db digital, within a normal ±10-v analog system. As described, the ranging circuit reduces the gain of the amplifier by a factor of either 4 or 16 whenever the output signal approaches the maximum for the system. The wide-band response is achieved with low-noise operational amplifiers and second-order active filters. Signals with periods greater than 30 sec are amplified by 100 db and those with periods shorter than 1 sec are amplified by 70 db. The system works well in extending the useful output range of a Willmore Mark II seismometer with a natural period of 1.5 sec to over 40 sec under normal field operating conditions. When analog recording, the gain-range switching occurs when the input signal reaches ±8.1-v; when digital recording, the level is ±9.375 v. The period in a divide-by-4- or 16-state is preset by the experimentalist. The gain level is recorded on an extra channel which is also used to record absolute time.


2004 ◽  
Vol 1 (3) ◽  
pp. 37-44 ◽  
Author(s):  
Dragisa Milovanovic ◽  
Milan Savic ◽  
Miljan Nikolic

As a part of wider project sigma-delta modulator was designed. It represents an A/D part of a power meter IC. Requirements imposed were: SNDR and dynamic range > 50 dB for maximum input swing of 250 mV differential at 50 Hz. Over sampling ratio is 128 with clock frequency of 524288 Hz which gives bandwidth of 2048 Hz. Circuit is designed in 3.3 V supply standard CMOS 0.35 ?m technology.


2005 ◽  
Author(s):  
A. M. Swidan ◽  
S. M. El‐Ghanam ◽  
H. A. Ashry ◽  
F. A. S. Soliman ◽  
W. Abdel‐Basit

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Sergei Krutchinsky ◽  
Nikolai Prokopenko

The sufficient conditions for the efficient use of active elements are formulated by analyzing the basic structure of second-order unit. The expediency of current amplifiers usage in HF and SHF filters is shown. The examples of a methodical nature are given and conclusions of application importance are formulated.


2020 ◽  
Vol 28 (4) ◽  
Author(s):  
Maad Mohsin Mijwil ◽  
Rana Ali Abttan

In this paper, we have applied the genetic algorithm to the selection of the true values for RC (resistors/capacitors) as an essential role in the development of analogue active filters. The classic method of incorporating passive elements is a complex situation and can attend to errors. In order to reduce the frequency of errors and the human effort, evolutionary optimization methods are employed to select the RC values. In this study, Genetic algorithm (GA) is proposed to optimize the second-order active filter. It must find the values of the passive elements RC to get a filter configuration that reduces the sensitivities to variations as well as reduces design errors less than a defined height value, concerning certain specifications. The optimization problem which is one of the problems that must be solved by GA is a multi-objective optimization problem (MOOP). GA was carried out taking into account two possible situations about the values that resistors and capacitors could adopt. The obtained experimental results show that GA can be used to obtain filter configurations that meet the specified standard.


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