Current-mode filter structure using DO-OTA with dual current outputs Io and Io/n for low-frequency applications

2017 ◽  
Author(s):  
Dattaguru V. Kamath
Keyword(s):  
Low Frequency ◽  
Current Mode ◽  
Filter Structure

Current-mode integrator for voltage-controllable low frequency continuous-time filters

2003 ◽  
Vol 39 (12) ◽  
pp. 883 ◽  
Author(s):  
Z. Yang ◽  
T. Hinck ◽  
H.I. Cohen ◽  
A.E. Hubbard
Keyword(s):  
Continuous Time ◽  
Low Frequency ◽  
Current Mode ◽  
Continuous Time Filters

HIGH-ORDER MULTIPLE-MODE AND TRANSADMITTANCE-MODE OTA-C UNIVERSAL FILTERS

2012 ◽  
Vol 21 (05) ◽  
pp. 1250048 ◽  
Author(s):  
CHEN-NONG LEE
Keyword(s):  
Current Mode ◽  
High Order ◽  
Point Of View ◽  
Chip Area ◽  
Operational Transconductance Amplifiers ◽  
Filter Structure ◽  
Multiple Mode ◽  
Input Signals ◽  
Theoretical Predictions ◽  
Low Sensitivity

This paper presents two new high-order OTA-C universal filters. The first proposed filter structure employs n + 3 operational transconductance amplifiers (OTAs) and n grounded capacitors, which can realize nth-order multiple-mode (including voltage, current, transadmittance, and transimpedance modes) universal filtering responses (lowpass, highpass, bandpass, bandreject, and allpass) from the same topology. Since the OTA has high input and output impedances, it is very suitable for transadmittance-mode circuit applications. Therefore, a new high-order transadmittance-mode OTA-C universal filter structure using the minimum components is introduced. The second proposed filter structure uses only n + 1 OTAs and n grounded capacitors, which are the minimum components necessary for realizing nth-order transadmittance-mode universal filtering responses (lowpass, highpass, bandpass, bandreject, and allpass) from the same topology. This represents the attractive feature from chip area and power consumption point of view. Moreover, the two new OTA-C universal filters still enjoy many important advantages: no need of extra inverting or double-type amplifiers for special input signals, using only n grounded capacitors, no need of any resistors, cascadably connecting the former voltage-mode stage and the latter current-mode stage, and low sensitivity performance. H-Spice simulations with TSMC 0.35 μm process and ±1.65 V supply voltages are included and confirm the theoretical predictions.

scholarly journals Effect of Pulse Current Mode on Microstructure, Composition and Corrosion Performance of the Coatings Produced by Plasma Electrolytic Oxidation on AZ31 Mg Alloy

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 688 ◽  
Author(s):  
Maryam Rahmati ◽  
Keyvan Raeissi ◽  
Mohammad Reza Toroghinejad ◽  
Amin Hakimizad ◽  
Monica Santamaria
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Low Frequency ◽  
Current Mode ◽  
Mg Alloy ◽  
Corrosion Performance ◽  
Micro Cracks ◽  
Az31 Mg Alloy ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Peo Coatings

Plasma electrolytic oxidation (PEO) coatings were grown on AZ31 Mg alloy in a silicate-based electrolyte containing KF using unipolar and bipolar (usual and soft-sparking) waveforms. The coatings were dual-layered consisting of MgO, MgF2 and Mg2SiO4 phases. Surface morphology of the coatings was a net-like (scaffold) containing a micro-pores network, micro-cracks and granules of oxide compounds. Deep pores were observed in the coating produced by unipolar and usual bipolar waveforms. The soft-sparking eliminated the deep pores and produced the lowest porosity in the coatings. It was found that the corrosion performance of the coatings evaluated using EIS in 3.5 wt. % NaCl solution is mostly determined by the inner layer resistance, because of its higher compactness. After 4 days of immersion, the inner layer resistances were almost the same for all coatings. However, the coatings produced by unipolar and usual bipolar waveforms showed sharp decays in inner layer resistances after 1 week and even the barrier effect of outer layer was lost for the unipolar-produced coating after 3 weeks. The low-frequency inductive loops appeared after a 3-week immersion for all coatings indicated that the substrate was under local corrosion attack. However, both coatings produced by soft-sparking waveforms provided the highest corrosion performance.

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