King Fahd University of Petroleum and Minerals

Muhammad Taher Abuelma'Atti

Zainulabideen Jamal Khalifa

Sagar Kumar Dhar

Munir A Al-Absi

Eyas Saleh Al-Suhaibani

Noman Tasadduq

Saad Radhi Alabbas

Ali Muhammad Taher Abuelma'Atti

Abdullah Muhammad Taher Abuelmaatti

Mohanad Ahmed Mohammed Elhassan Ahmed

Husam Al-Shammari

Abdullah M T Abuelma'atti

Nawal Mansour Al-Yahia

Eyas Saleh Alsuhaibani

Zainualbideen Jamal Khalifa

A tunable impedance multiplier with high multiplication factor is described. A single externally connected resistor is used and the multiplier is free of passive elements. The circuit can realize a positive or a negative impedance multiplier. Applications of the design to low and high pass filters are also presented. The simulation and experimental results show that the new design enjoys a multiplication factor above 400 at 2 Hz-to 7 MHz.

Method for tunably multiplying an impedance

Tunable grounded positive and negative impedance multiplier

A time-to-voltage converter (TVC) that can include a timer integrated circuit (IC), and a charging circuit including a constant current source and a capacitor connected in series. The capacitor can be connected to a discharge pin of the timer IC. The TVC can further include a trigger circuit and a reset circuit to receive a start signal and a stop signal, respectively, from an input line, and accordingly generate a trigger signal or a reset signal to trigger or reset the timer IC. A switch can be configured to, under control of an output signal of the timer IC, connect the input line with the reset circuit. A voltage across the capacitor when the timer IC is reset indicates a time interval corresponding to the start and stop signals.

Time-to-voltage converter

A time-to-voltage converter (TVC) including a 555 timer integrated circuit (IC), and a charging circuit including a constant current source and a capacitor connected in series. The capacitor can be connected to a discharge pin of the 555 timer IC. The TVC can further include a trigger circuit and a reset circuit to receive a start signal and a stop signal, respectively, from an input line, and accordingly generate a trigger signal or a reset signal to trigger or reset the 555 timer IC. A switch can be configured to, under control of an output signal of the 555 timer IC, connect the input line with the reset circuit. A voltage across the capacitor when the 555 timer IC is reset indicates a time interval corresponding to the start and stop signals.

Range finding device

A time-to-voltage converter (TVC) that includes a 555 timer integrated circuit (IC), and a charging circuit including a constant current source and a capacitor connected in series. The capacitor can be connected to a discharge pin of the 555 timer IC. The TVC can further include a trigger circuit and a reset circuit to receive a start signal and a stop signal, respectively, from an input line, and accordingly generate a trigger signal or a reset signal to trigger or reset the 555 timer IC. A switch can be configured to, under control of an output signal of the 555 timer IC, connect the input line with the reset circuit. A voltage across the capacitor when the 555 timer IC is reset indicates a time interval corresponding to the start and stop signals.

555-timer based time-to-voltage converter

The floating immittance emulator is presented in four embodiments in which four new topologies for emulating floating immittance functions are detailed. Each circuit uses three current-feedback operational-amplifiers (CFOAs) and three passive elements. The present topologies can emulate lossless and lossy floating inductances; capacitance, resistance, and inductance multipliers; and frequency-dependent positive and negative resistances.

Floating immittance emulator

The floating memristor emulator is based on a circuit implementation that uses grounded capacitors and CFOAs in addition to combinations of diodes and resistors to provide the required nonlinearity and time constants. This circuit results in low power consumption, cost reduction and ease of implementation because it avoids the use of multipliers, ADCs and RDACs. The present circuit is used in an FM demodulator, which exploits the frequency-dependence of the memristance. Successful use in the FM demodulator confirmed the functionality of the present floating memristor emulator circuit.

Floating memristor emulator

The compact C-multiplier includes four MOSFETs operating in the subthreshold region using the translinear principle. The multiplier is controllable to meet designer requirements. A Tanner Tspice simulator is used to confirm the functionality of the design in 0.13 pm CMOS Technology. The circuit operates from a &#xb1;0.75 supply voltage. Simulation results indicate that the multiplication factor is large compared to existing designs.

Compact C-multiplier

The current-feedback operational amplifier-based sinusoidal oscillator circuit includes a pair of CFOAs connected to each other using five resistors and two capacitors. The condition and the frequency of oscillation are fully coupled, and thus none of them can be controlled without disturbing the other. The oscillator circuit provides a high impedance output current and two low impedance output voltages.

Current-feedback operational amplifier-based sinusoidal oscillator

The logarithmic and exponential function generator for analog signal processing is implemented with CMOS circuits operating in current mode and includes current mirrors connected to a square root function circuit and two current amplifiers. A third current amplifier utilizes a constant current input. The outputs of the current amplifiers are combined to provide the logarithmic and exponential functions.

Logarithmic and exponential function generator for analog signal processing

The current-mode folding amplifier is a current-mode saw-tooth folding amplifier having a minimal number of current mirrors in the signal path from input to output. This minimizes the delays imposed by current mirrors on the speed of the amplifier. The amplifier has a full scale delay of 5.9 ns. The operation of the amplifier is verified in simulation using LFoundry 150 nm process in Cadence Tools.

Current-mode folding amplifier

The continuous-level memristor emulator is a circuit that uses off-the-shelf components to emulate a memristor. The circuit uses two current-feedback operational-amplifiers (CFOAs) and uses an operational transconductance amplifier (OTA)-based circuit in place of a diode resistive network to provide a continuous level of memristance instead of two binary states. The OTA is forced to work in its nonlinear region by the voltage Vapplied to its positive input terminal. Thus, the transfer function of the OTA-based circuit will be a nonlinear function. Experimental testing shows that the continuous-level memristor emulator is operational as a memristor, and the emulator may be used, e.g., in place of a memristor in a multivibrator circuit.

Growing community of inventors

Dhahran, Saudi Arabia

Muhammad Taher Abuelma'Atti