Electronically controllable third-order quadrature sinusoidal oscillator employing CMOS-OTAs

Third‐order quadrature sinusoidal oscillators with fully uncoupled tuning laws using only two CFOAs and grounded capacitors

“…A survey of previously reported VM TOQSOs based on three ABBs reveals that they suffer from one or more of the following drawbacks: (i) not employing all grounded capacitors, 8,9 (ii) nonavailability of independent control of CO and FO, 8,10,12,16,24 (iii) nonavailability of output voltages from low output impedance nodes, [9][10][11][12][13][14][15][16][17][18][19] and use of ABBs that are not yet commercially available. [13][14][15][16][17][18][19]24 From the various three-ABBs-based TOQSOs, only those of the previous studies [20][21][22][23] are based upon three CFOAs, which employ all the three grounded capacitors and also provide independent control of CO and FO.…”

“…Of late, there also has been considerable research effort on third‐order oscillators since they are expected to provide high‐quality waveforms with low harmonic distortion 2,3 . Consequently, many authors have proposed third‐order quadrature oscillators using a variety of active building blocks (ABB) such as op‐amps, operational transconductance amplifiers (OTA), current differencing transconductance amplifiers (CDTA), multiple‐input second‐generation current conveyors (MOCCII), current differencing buffered amplifiers (CDBA), operational transresistance amplifiers (OTRA), voltage differencing buffered amplifiers (VDBA), differential voltage current conveyors (DVCC), differential difference current conveyors (DDCC), current controlled current conveyors (CCCII), voltage differencing transconductance amplifiers (VDTA), multiple‐output current controlled current conveyor transconductance amplifiers (MOCCCCTA), modified current following transconductance amplifiers (MCFTA), current‐controlled current conveyor transconductance amplifiers (CCCCTA), differential voltage current conveyor transconductance amplifiers (DVCCTA), voltage differencing inverting buffered amplifiers (VDIBA), fully differential second‐generation current conveyors (FDCCII), voltage differencing current conveyors (VDCC), and many more 4–51 …”

Systematic realization of low‐frequency third‐order sinusoidal oscillators

“…30 • Oscillators in which the design approaches have not been mentioned explicitly. [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49]51,53,54 The main aim of this paper is, thus, to present an approach for systematic realization of third-order LF sinusoidal oscillators (TOLFSOs) realized with minimum number of resistors and grounded capacitors with independent control of CO and FO with different resistors.…”