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In this paper, a new single-resistance controlled sinusoidal oscillator (SRCO) using single universal voltage conveyor (UVC) has been presented. The proposed SRCO employs single universal voltage conveyor, three resistors, and two capacitors. The proposed configuration offers the following advantageous features (1) independent control of condition of oscillation and frequency of oscillation (2) low passive sensitivities. The validity of the proposed SRCO has been established by SPICE (version 16.5) simulations using Taiwan Semiconductor Manufacturing Company (TSMC) 0.18 μm technology.

Implementation of sinusoidal oscillators and active biquadratic filters has become important modern analog active building blocks that have been introduced in [

The symbolic notation and equivalent circuit model of UVC are shown in ^{+}, y^{−}), two mutually inverse voltage outputs (z^{+}, z^{−}), and one auxiliary port w. The UVC can be described by the following set of equations.

( I x I w V y + V y − V z + V z − ) = ( 0 0 1 − 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 − 1 0 0 0 0 0 ) ( V x V w I y + I y − I z + I z − ) (1)

The circuit of proposed SRCO is drawn in

Routine circuit analysis (assuming ideal UVC) of

CE: s 2 C 1 C 2 + s C 2 R 1 R 2 ( R 3 − R 1 ) + 1 R 1 R 2 = 0 (2)

Thus, the condition of oscillation (CO) and frequency of oscillation (FO) are given by

CO: ( R 3 R 1 − 1 ) ≤ 0 (3)

FO: ω 0 = 1 C 1 C 2 R 1 R 2 (4)

Taking into account the non-idealities of UVC, the relationship between the port voltages and currents is shown by the hybrid matrix:

( I x I w V y + V y − V z + V z − ) = ( 0 0 α 1 − α 2 0 0 0 0 0 0 0 0 0 δ 1 0 0 0 0 0 δ 2 0 0 0 0 γ 1 0 0 0 0 0 − γ 2 0 0 0 0 0 ) ( V x V w I y + I y − I z + I z − ) (6)

where α j = 1 − ε i j and δ j = 1 − ε v 1 j , γ j = 1 − ε v 2 j for j = 1 , 2 . Here ε i j ( | ε i j | ≪ 1 ) and ε v 1 j , ε v 2 j ε i j ( | ε v 1 j | , | ε v 2 j | ≪ 1 ) represent the current and voltage tracking errors of the UVC respectively. The parasitic present on the low impedance ports (y^{+}, y^{−}, z^{+}, z^{−}) are quite low as compared to the resistances on the other ports (w and x) [

CE: s 2 C 1 C 2 R 1 R 2 α 2 ( γ 1 R 2 + γ 1 R 3 − δ 2 R 3 ) + s R 2 ( α 2 γ 1 C 1 R 1 + α 1 δ 1 C 2 R 3 − α 2 δ 2 C 1 R 1 − C 2 R 1 ) + α 1 δ 2 R 2 = 0 (7)

CO: ( α 2 γ 1 C 1 R 1 + α 1 δ 1 C 2 R 3 − α 2 δ 2 C 1 R 1 − C 2 R 1 ) ≤ 0 (8)

FO: ω 0 = α 1 δ 2 C 1 C 2 R 1 α 2 ( γ 1 R 2 + γ 1 R 3 − δ 2 R 3 ) (9)

The various sensitivities of FO can be found as

S C 1 ω 0 = S C 2 ω 0 = S R 1 ω 0 = S α 2 ω 0 = − 1 2 , (10a)

S R 2 ω 0 = − 1 2 ( γ 1 R 2 γ 1 R 2 + γ 1 R 3 − δ 2 R 3 ) , (10b)

S α 1 ω 0 = 1 2 (10c)

S γ 1 ω 0 = − 1 2 γ 1 ( R 2 + R 3 ) ( γ 1 R 2 + γ 1 R 3 − δ 2 R 3 ) , (10d)

S δ 2 ω 0 = 1 2 ( 1 + R 3 α 1 δ 2 ( γ 1 R 2 + γ 1 R 3 − δ 2 R 3 ) ) (10e)

S R 3 ω 0 = − 1 2 ( R 3 ( γ 1 − δ 2 ) α 1 δ 2 ( γ 1 R 2 + γ 1 R 3 − δ 2 R 3 ) ) (10f)

In the ideal case, the various sensitivities of ω_{0} with respect to R_{1}, R_{2}, C_{1} and C_{2} are given as

S C 1 ω 0 = S C 2 ω 0 = S R 1 ω 0 = S R 2 ω 0 = − 1 2

To confirm the validity of the presented SRCO, the circuit was simulated using SPICE. The voltage and current values selected for CMOS implementation of UVC are ±1.9 V and 100 µA, respectively. The passive elements were chosen as C_{1} = C_{2} = lnF, R_{1} = R_{2} = 2.4 kΩ and R_{3} = 2.331 kΩ. The transient and steady state response of the proposed SRCO for the selected passive components are shown in

A new voltage-mode single-resistance controlled sinusoidal oscillator employing single UVC has been proposed. The presented SRCO circuit employs single UVC, two capacitors and three resistors. The presented configuration offers (1) independent control of frequency of oscillation can be controlled by resistance

Transistors | W (µm) | L (µm) |
---|---|---|

M5-M8, M10, M15-M18, M20 | 14.0 | 0.7 |

M3, M4 | 28 | 0.7 |

M25, M26, M34, M35 | 4.0 | 0.5 |

M27, M36 | 10.0 | 0.5 |

M32, M33 | 2.1 | 1.0 |

M1, M2 | 14.0 | 0.7 |

M9, M11-M14, M19, M21-M24 | 28 | 0.7 |

M28, M29, M37, M38 | 0.8 | 05 |

M30, M31, M39, M40 | 10 | 0. 5 |

R_{2} and condition of oscillation can be adjusted by resistance R_{3}, (2) low passive sensitivities. Simulation results using 0.18 μm TSMC CMOS technology have been presented to confirm the workability of the proposed new SRCO. This paper thus added a new application configuration to the existing repertoire of UVC based application circuits. For future one can reduce the passive elements or transistors in the device (UVC).

Pushkar, K.L. (2018) Single-Resistance Controlled Sinusoidal Oscillator Employing Single Universal Voltage Conveyor. Circuits and Systems, 9, 1-7. https://doi.org/10.4236/cs.2018.91001