Abstract: An oscillator circuit includes a Wien-bridge oscillator. A non-detuned oscillating signal and a detuned oscillating signal are tapped from the Wien-bridge oscillator. A sum of a weighted detuned signal and a weighted non-detuned signal is coupled as feedback signal to the Wien-bridge to control the oscillation amplitude.

Abstract: Disclosed herein is a sine wave oscillator having a self-startup circuit. The sine wave oscillator can start up and output sine waves having a constant frequency without receiving any signals other than supply voltage. The sine wave oscillator includes an operational amplification unit, a first resistor, a first capacitor, a second capacitor, a second resistor, a third resistor, a fourth resistor, and a startup circuit.

Abstract: Method for stabilizing the frequency of a MEMS (Micro Electro Mechanical Systems) reference oscillator, and a MEMS reference oscillator, wherein the method comprises following steps: using two or more MEMS components, wherein each MEMS component is characterized by a set of properties, and selectively combining the desired properties from the MEMS components.

Abstract: In a Wien-Robinson oscillator, a negative feedback path and a positive feedback path are arranged between the output of an operational amplifier and a reference ground potential. The negative feedback path contains two resistors which are connected in series and whose common circuit point is connected to the inverting input of the operational amplifier. The positive feedback path is formed from two RC elements which are connected in series and whose common circuit point is connected to the non-inverting input of the operational amplifier. If the aim is to keep the amplitude of the output voltage from the oscillator constant, additional measures are required, which increase the circuitry complexity. In order to stabilize the output voltage from the oscillator with little complexity, a third resistor is arranged between the output of the operational amplifier and that end of the positive feedback path which faces away from the reference ground potential.

Abstract: A tuning circuit includes an oscillator that receives an oscillating input signal and a control signal, and generates an oscillating output signal. The control signal is obtained from a frequency control circuit that compares the phases of the oscillating output signal and a reference signal. The control signal controls the transconductance of a transconductance element in the oscillator, thereby controlling the oscillator output frequency. The oscillating input signal is obtained from an amplitude control circuit that detects an amplitude limit of the oscillator output. The oscillator output amplitude is responsive to the oscillating input signal. Frequency control and amplitude control in this tuning circuit are mutually independent, so their respective control loops remain stable under all frequency and amplitude combinations.

Abstract: The present invention relates to a device for generating a sinewave output signal and comprising an oscillator. The oscillator includes means for respectively connecting and disconnecting one of the device supply voltages, such that when connecting said supply voltage the sinewave output signal will be stabilised after a time period corresponding to an interval of 1-5 periods of the sinewave output signal.

Abstract: The device for the recovery of a timing signal comprises a oscillator (3) which includes an amplifier (4); a first impedance (Z1) connected between a first input and the output of the amplifier and a second impedance (Z2) also connected between the first input of the amplifier and ground. A third resistive impedance (R1) is connected between a second amplifier input and the amplifier output. A fourth resistive impedance (R2) is connected between the second amplifier input and an injection point of a voltage that corresponds the signal from which the timing signal is to be recovered.

Abstract: A temperature to frequency converter includes two temperature detectors having an electrical characteristic, such as resistance, that varies proportionally with sensed temperature. These devices are connected into an oscillator circuit that provides an electrical signal output having a frequency inversely proportional to sensed temperature. An amplitude control feedback loop connected to the oscillator circuit maintains the amplitude of the output signal constant.

Abstract: A phase-lock loop system incorporates a normally "transparent" oscillator used in detecting whether or not the system is in a locked condition. It is essential that the oscillator, a portion of which is serially involved in the phase-lock loop, have a long time constant, so as to minimally affect the closed loop's transfer function during phase-locked conditions. It is desirable, however, that when the phase-lock loop loses lock that the time constants of the transparent oscillator change to much smaller values for quick response of the oscillator and operation at a high frequency for detection purposes and quick extinction when phase-lock is acquired. The detection of oscillation of the transparent oscillator initiates the application of a low speed sweep signal being applied to the voltage controlled oscillator portion of the phase-lock loop to reestablish phase-locked conditions and eventually return of the transparent oscillator to its long time constant values.

Abstract: An embedded circuit is placed in a phase-locked loop having the normal phase detector and voltage-controlled oscillator. The embedded circuit is transparent to phase-locked conditions of the loop and becomes operative in an oscillatory mode only when the loop loses its lock. An oscillatory detector is used to detect the oscillatory condition of the embedded circuit and causes the application of a sweep signal to the voltage-controlled oscillator to reestablish phase-locked conditions in the overall phase-locked apparatus.

Abstract: An RC oscillator comprising an amplifier with a first RC voltage divider coupling its output circuit to its non-inverting input circuit and a second RC voltage divider coupling its non-inverting input circuit to its inverting input circuit. The first RC voltage divider comprises a series RC network in its series arm and parallel RC network in its shunt leg. The second RC voltage divider has a capacitor in its series arm and a resistor in its shunt leg.

Abstract: A distortion measurement system for measuring distortion as low as 0.002% includes an ultra low distortion oscillator having a relatively fast response which is achieved by switching the time constant of the control loops of the oscillator during settling. The analyzer section included in the distortion system has a unique notch filter which provides low distortion. This is achieved by adding together two 90.degree. all pass phase shifters. In addition, automatic tuning is provided by two feedback control loops; one is responsive to out-of-phase signals which controls the RC filter circuits of the phase shifters and the other responds to the in-phase signals which controls the output summing junction of the notch filter. Finally, a feedforward type of simultaneous tuning is accomplished by ganging the oscillator frequency adjustment with the analyzer.