Current-mode multiphase sinusoidal oscillator using CDTA-based allpass sections

Electronically Controllable Current-Mode Multiphase Sinusoidal Oscillator for Biomedical Tissue Measurement Systems

“…Moreover, the output currents of the MSO, utilizing the CDTA-based lossy integrators, are of different amplitudes. The MSO employing CDTA-based allpass sections [13] requires two CDTAs in each allpass section, and the circuitry becomes more extensive. While MSO using CDTA-based allpass sections [14] requires floating capacitor.…”

“…They exhibit good performance in terms of electronic tunability, high-output impedances, and independent control of the oscillation frequency and the oscillation condition. However, MSOs in [12], [13] require an additional current amplifier, which is implemented by two CDTAs. Moreover, the output currents of the MSO, utilizing the CDTA-based lossy integrators, are of different amplitudes.…”

“…The second reported circuit requires additional current amplifiers, which makes the circuit more complicated and increases its power consumption. CDTA-based current-mode MSOs in [12] is based on lossy integrators, where as the circuits in [13] and [14] contain CDTA-based allpass sections. They exhibit good performance in terms of electronic tunability, high-output impedances, and independent control of the oscillation frequency and the oscillation condition.…”

All Pass Network Based MSO Using OTRA

“…Three topologies of OTRA based MSOs are proposed in [16] and are designed using LPNs. The structures proposed in [2,[17][18][19][20][21][22][23][24][25] provide current outputs which need to be converted back to voltage for circuits requiring voltage inputs, which would considerably increase the component count. A detailed comparison of these structures is given in Table 1 which suggests that OTRA based MSO is the most suitable choice for voltage output.…”

“…These MSOs are based on a basic design philosophy of forming closed loop using ( ≥ 3) cascaded phase shifting networks thereby producing equally spaced phases. For phase shifting either first-order low pass networks (LPNs) [5-7, 9-21, 24, 25] or first-order all pass networks (APNs) [2,8,22,23] are used. These reported structures provide either voltage [5][6][7][8][9][10][11][12][13][14][15][16] or current [2,[17][18][19][20][21][22][23][24] outputs.…”