New sinusoidal oscillator configurations using operational transresistance amplifier

Abstract

The objective of this brief is to introduce four new structures of electronically tunable sinusoidal oscillators (SOs) designed using operational transresistance amplifier (OTRA). Each of the proposed SO consists of forward path derived from a generic structure along with one/two OTRA-based resistive gain stages or differentiator in its feedback path. All the proposed SOs enjoy independent tuning of the frequency of oscillation (FO) through resistors without affecting the condition of oscillation (CO). Further, all topologies are found to exhibit low f o sensitivities at all frequencies with respect to circuit parameters, and the second topology is capable of achieving very low frequencies (VLFs) using less RC component spread and provides linear tuning too. The fourth circuit provides quadrature output. The proposed SOs have been successfully implemented and verified in 180-nm CMOS technology node using ADE (analog design environment) tool Cadence Virtuoso. Both prelayout and postlayout simulation results have been included. To assess the oscillator prefabrication performances, Monte Carlo and process-voltage-temperature (PVT) analyses have been performed. The total harmonic distortion (THD) is observed to be less than 3.5%.

Mutually coupled circuits based on modified voltage differencing transconductance amplifier with tuneable characteristics

“…The Monte Carlo-MC analysis offers a unique tool to study and analyze the robustness, as well as the uncertainty of the proposed realizations of the MMCs for transistor mismatch. 22 The MC simulation is performed 200 times, with 5% Gauss deviation of gate oxide thickness (t ox ) and relevant transistors width and length (of all the MOS transistors) and 10% Gauss deviation of V TH0 (threshold voltage) are achieved as in Figure 11A-a histogram is given to show the distribution of the maximum gain of the proposed DTBP filter configuration 4 (specified in above text, for f 0 = 918.88 kHz and Q = 5.77). Assuming that the values of all passive elements (R, C) uniformly changed by 5% (Figure 11B), 4 MC analysis is also performed for the DTBP filter.…”

Electronically Tunable Grounded and Floating Capacitance Multipliers Using a Single Active Element

“…IB, or the bias current, is used to adjust the transconductance gain of the VDDDA electronically. Although the proposed circuit requires a foating capacitor, the metal-oxide-metal (MOM), double poly (poly1-poly2), or metal-insulator-metal (MIM) capacitor processes can be used to fabricate the foating capacitor [58]. Based on equation ( 1), a circuit analysis can be performed to determine the grounded capacitance multiplier's input impedance (the ratio of v in to i in ), which is defned as…”

Electronically Adjustable Capacitance Multiplier Circuit with a Single Voltage Differencing Gain Amplifier (VDGA)

“…It consists of only one VDGA and one floating capacitor. Although the floating capacitor is required, it can be implemented using metal-oxide-metal (MOM) double poly (poly1-poly2) or metal-insulator-metal (MIM) capacitor process [24]. Considering the VDGA port relation (1), the input impedance of the proposed capacitance multiplier circuit is…”