Abstract: In accordance with some embodiments of the present disclosure, an oscillator may include a crystal resonator and a squaring circuit coupled to the crystal resonator and configured to convert a sinusoidal signal produced by the crystal resonator to a square-wave signal, the squaring circuit comprising a bias circuit configured to transmit a selected bias voltage for the squaring circuit, the selected bias voltage selected from a plurality of potential bias voltages. In accordance with this and other embodiments of the present disclosure, an oscillator may include a crystal resonator, an inverter coupled in parallel with the crystal resonator, and a programmable voltage regulator coupled to the inverter. The programmable voltage regulator may be configured to supply a first supply voltage to the inverter during a startup duration of the oscillator, and supply a second supply voltage to the inverter after the startup duration, wherein the second supply voltage is lesser than the first supply voltage.

Abstract: A constant-temperature piezoelectric oscillator includes: a piezoelectric vibrator; an oscillation circuit; a frequency voltage control circuit; a temperature control section; and an arithmetic circuit, wherein the temperature control section includes a temperature-sensitive element, a heating element, and a temperature control circuit, the frequency voltage control circuit includes a voltage-controlled capacitance circuit capable of varying the capacitance value in accordance with the voltage, and a compensation voltage generation circuit, and the arithmetic circuit makes the compensation voltage generation circuit generate a voltage for compensating a frequency deviation due to a temperature difference between zero temperature coefficient temperature Tp of the piezoelectric vibrator and setting temperature Tov of the temperature control section based on a frequency-temperature characteristic compensation amount approximate formula adapted to compensate the frequency deviation, and then applies the voltage t

Abstract: A voltage source circuit for a crystal oscillation circuit is provided, in which the voltage source circuit and the crystal oscillation circuit are formed with the same process. The voltage source circuit includes a current source, a first PMOS, a first NMOS and a regulator unit. The current source is coupled between a voltage source and an output terminal, in which the output terminal outputs a reference voltage. Both of the gates and drains of the first PMOS and the NMOS are coupled to each other, and the first PMOS and the first NMOS are coupled between the output terminal and a ground. The regulator unit generates a work voltage to the crystal oscillation circuit as a voltage source of the crystal oscillation circuit according to the reference voltage.

Abstract: An oscillation driver device includes a gain control amplifier, an automatic gain control circuit, and a mode setting circuit. When the mode setting circuit has switched a mode from a normal operation mode to a low power consumption mode, the automatic gain control circuit is disabled, and the gain in an oscillation loop that drives the vibrator changes from a state in which the gain in the oscillation loop is controlled to be unity by the automatic gain control circuit to a state in which the gain in the oscillation loop is set to be larger than unity. When the mode setting circuit has switched the mode from the low power consumption mode to the normal operation mode, the automatic gain control circuit resumes operation, and the gain in the oscillation loop changes from the state in which the gain in the oscillation loop is set to be larger than unity to the state in which the gain in the oscillation loop is controlled to be unity by the automatic gain control circuit.

Abstract: A high-performance crystal oscillator providing effective bias resistors with low power consumption and minimal substrate surface area. In various embodiments of the invention, a switched-capacitor resistor is operably coupled to circuit components, such as an oscillation source, a current source, an input buffer, or an amplifier to provide a bias resistance.

Abstract: A low power balanced Colpitts oscillator circuit with improved negative resistance. The oscillator circuit comprises two cross-coupled Colpitts oscillators with a crystal oscillator connected between the two oscillators. A single current source can be used for both Colpitts oscillators since only one Colpitts needs a current source at a time. Using a single current source cuts the power consumption in half. Alternatively, a transistor in each Colpitts oscillator can act as a current source, which is turned on or off depending on the state of the Colpitts transistor. The two current sources are biased at a common level and matched to ensure the circuit remains symmetrical. An additional benefit of the present invention is that the negative resistance is directly improved.

Abstract: An oscillator circuit suppresses unwanted oscillation frequencies and allows oscillation in the selected frequency band. The circuit has less sensitivity to aging of components that cause a shift in operating frequency. The oscillator includes a first and second inverting amplifier that each have an input terminal and an output terminal. A crystal resonator is connected between the input terminal of the first amplifier and the output terminal of the second amplifier. A suppression trap is connected between the first and second amplifier for suppressing oscillation outside the desired range of frequencies. The trap includes a parallel tank circuit that is connected between the output terminal of the first amplifier and the input terminal of the second amplifier. A capacitor is connected between the input terminal of the second amplifier and a ground.

Abstract: In the method, following an operating point determination of the quartz resonator circuit, a substitution of the equivalent circuit diagram of the quartz resonator by an independent current source is implemented with the initial, previously determined amplitude of the current of the dynamic arm of the quartz resonator. The dynamic equilibrium state is determined for this circuit arrangement with firing methods or methods of harmonic balance. After a resubstitution of the current source by the equivalent circuit diagram of the quartz resonator, a transient analysis is implemented for the dynamic equilibrium state. This method is iteratively implemented as long as the identified growth rate lies above a prescribable barrier.

Abstract: A low power, fast starting oscillator (10) of the Colpitts type includes an amplifier (12) that provides voltage gain and feeds a source follower circuit (14) that provides a desirable output impedance. A crystal (16) is coupled from an output of the source follower circuit (14) back to the amplifier's input (32). The voltage gain of the amplifier (12) and the output impedance of the source follower circuit (14) are independently selectable to provide an optimum transconductance for the oscillator (10) to start quickly. When oscillations reach a threshold value, the transconductance may be reduced to save power.

Abstract: A one-pin integrated crystal oscillator in a Colpitts configuration employs a differential amplifier, provided with a feedback network, as an input gain stage. This achieves an enhanced stability and independence from temperature variation, a high Q figure, and a short start-up with a relatively small area of integration.

Abstract: An oscillator is provided with an internal, high gain hysteresis effect so as to offset the linear regions of the waveform and to avoid spikes upsetting the count of a reference divider controlling the oscillator. The crystal (10) and capacitor (11) are connected between the base of one (T.sub.1) and the collector of the other (T.sub.2) transistor of a long-tailed pair, signals appearing at the collector thereof being fed via emitter followers (T.sub.5, T.sub.6) to a further long-tailed pair (T.sub.7, T.sub.8) having tapped collector resistors (R.sub.1, R.sub.2). The signal appearing at the tapping point of one of the further pair (T.sub.7) is fed to the base of a transistor (T.sub.3) whose collector-emitter resistor lies in the load circuit of one of the transistors (T.sub.1) of the first long-tailed pair.

Abstract: A crystal oscillator comprising a crsytal and an inverter amplifier which utilizes a current mirror to provide a voltage output having a frequency double the frequency of the voltage waveform present in the inverter amplifier.

Abstract: The resonant frequency of a quartz-crystal microwave oscillator is the fundamental frequency in the partial mode of the crystal and makes it possible to maintain the loaded Q of the resonator at a high value. This microwave oscillator is provided with two amplifying stages and has a signal-to-noise ratio of the order of 160 dB.

Abstract: To increase the gain and, consequently, to increase the voltage amplitude appearing at the crystal of a crystal oscillator a conventional circuit including a first differential amplifier in the amplifier section and two further differential amplifiers in the phase shifting section is modified to include a fourth differential amplifier in the amplifier section. The fourth amplifier carries an additional current to flow in the two differential amplifiers causing an additional current to flow and across the operating resistance of the two differential amplifiers an additional voltage drop being fed to the crystal via an emitter follower.

Abstract: A narrow band, voltage controlled crystal oscillator having a linear frequency versus tuning voltage response. The oscillator uses a composite resonator in a novel circuit configuration with a resulting improvement in oscillator output signal frequency stability.

Abstract: An overtone oscillator of the feedback type is provided by a transistor, a crystal resonant at a fundamental frequency and higher odd overtone frequencies, and a feedback circuit that includes the crystal, a second transistor connected in cascade with the first transistor and an RC network. This feedback circuit provides the correct phase shift to achieve and sustain oscillations at the desired overtone frequency.

Abstract: An amplitude limiting amplifier followed by a filter network is interposed between the voltage amplification stage and the impedance matching stage in a Butler oscillator. This allows both the voltage amplification stage and the impedance matching stage to be operated in a linear mode at all times which assures that a piezoelectric crystal connected between the stages is connected in a relatively low, constant impedance path and is driven by a sinusoidal waveform, free of distortion, to assure maximum frequency stability.

Abstract: Disclosed is a circuit for locking a harmonic-rich oscillator, such as the crystal-controlled type, to provide as its output, a signal at a designated frequency characterized by minimum harmonic content and high stability. The circuit includes a combination of gates in the oscillatory feedback path controlled by single-shot multivibrators with time constants such that any tendency of the period of the output signal to compress or expand is overridden by the respective expansion or compression thereof by the appropriate single-shots.

Abstract: A colpitts oscillator having a tank circuit and a common base connected transistor, operating in a linear range, with an emitter-base junction coupled in the tank circuit and a load in the collector circuit thereof for passing current through the load at the frequency of the tank circuit.