Relaxation oscillator

About: Relaxation oscillator is a research topic. Over the lifetime, 1952 publications have been published within this topic receiving 22326 citations.

Low-voltage high-speed PWM signal generations based on relaxation oscillator

Abstract: This paper new two simple PWM (pulse width modulation) signal generations based on a modified relaxation oscillator are introduced. The advantages of the proposed principle are that the precise PWM signal can be easily achieved with a high frequency range up to several megahertz and a low-voltage power supply. The proposed circuits are able to accept either voltage or current modulating signals. They are very suitable for developing into integrated circuit (IC) form in communication applications. The simulation and experimental results are also depicted, and show good agreement with theoretical predictions.

Voltage boosting device and method for semiconductor device

Abstract: A semiconductor device includes: a pump circuit that boosts an output node connected to a memory cell array; an oscillator that outputs a clock to the pump circuit; and a detection circuit that outputs an actuating signal to the oscillator. In this semiconductor device, the actuating signal actuates the oscillator when the voltage of the output node of the pump circuit is lower than a first reference voltage, and the actuating signal stops the oscillator when the voltage of the output node is higher than a second reference voltage. In accordance with the present invention, when the voltage of the output node of the pump circuit is higher than the target voltage, the oscillator is stopped, and so is the pump circuit. Thus, unnecessary charge flow to the ground can be prevented, and the power consumption of the booster circuit can be reduced.

Relaxation oscillator of low power consumption and high performance

Abstract: To overcome the defects that the transmission time-delay is indefinite, the frequency precision of oscillation is low and the temperature stability is poor in a relaxation oscillator, the invention provides a method by using feedback control and detects a signal value when a charge (or discharge) period of a timing capacitor in a constant speed (or a definite change velocity) is ended through a sampling hold circuit, so as to adjust the amplitude of a timing reference signal automatically and compensate the change of the time delay of a comparator, then the time of the charge (or discharge) period of the timing capacitor in the constant speed (or the definite change velocity) is precise and controllable, and the precision of an oscillation frequency and the temperature stability are improved on the promise that the energy consumption is hardly increased.

Capacity type displacement transducer

Abstract: PURPOSE:To eliminate the influence exercised by a distributed capacity, by a method wherein a capacity type sensor is used as a feedback capacity of an inversion amplifier to form a Miller integrator. CONSTITUTION:A capacity C1, in which an electrostatic capacity changes in proportion to a displacement of a process amount, is connected as a feedback capacity between an input and an output of an inversion amplifier Q1, and a resistor R1 is inserted in series into the input of the inversion amplifier Q1 to form the Miller integrator. Simultaneously, a trigger circuit Q2, having a hysteresis property, is inserted in series between the Miller integrator and the resistor R1 to form as a whole a relaxation oscillator which charges and discharges for the duration of a period corresponding to values of the resistor R1 and an electrostatic capacity C1. If the gain of the inversion amplifier Q1 is extremely large, the input potential of the inversion amplifier Q1 is kept constant through the integral action, whereby charging and discharging toward a distributed capacity CS1 are not conducted, and the presence of the distributed capacity CS1 can be ignored. Additionally, of the output impedance of the inversion amplifier Q1 is extremely small, the presence of a distributed capacity CS2 can also be ignored.

A novel cantilever acoustic sensor with frequency output based on resonant tunneling diodes

Abstract: This paper reports a novel GaAs cantilever acoustic sensor based on AlAs/InxGa1-xAs/GaAs resonant tunneling diode (RTD) with a frequency output. The RTD is incorporated in a 10 mum thick cantilever diaphragm and the fabrication technology of the cantilever diaphragm is based upon the micromachined control holes technology. A relaxation oscillator is obtained with the RTD biased in the negative differential resistance (NDR) region. Pressure applied to the RTD changes the frequency of oscillation due to the shift in current-voltage characteristics. The main feature of this sensor type is the direct frequency output and the sensitivity can be up to 102kHz/kPa