Abstract:
A voltage controlled oscillator (200) for generating a signal with a frequency range. The voltage controlled oscillator (200) comprises an oscillator core (210) comprising an amplifier (212) and a resonator (214) and a tunable capacitance cell (220) having an input/output port. The input/output port is connected to the resonator (214) of the oscillator core (210). The tunable capacitance cell (220) comprises a cross-coupled transistor pair (Q11; Q12), the base or gate of the first transistor (Q11) and the base or gate of the second transistor (Q12) are coupled to a control signal to tuning an input capacitance and conductance of the tunable capacitance cell (220).
Abstract:
A large gain is used to start up the oscillation of the crystal quickly. A control circuit disables a low resistance path based on the measured amplitude to reduce the power dissipation specification of the crystal. Another technique introduces a mixed-signal controlled power supply multi-path resistive array which tailors the maximum current to the crystal. A successive approximation register converts the amplitude into several partitions and enables/disables one of several power routing paths to the inverter of the oscillator. This allows a better match between the crystal selected by the customer and the on-chip drive circuitry to power up the oscillator without stressing the crystal. The "1/f" noise of the oscillator circuit is minimized by operating transistors in the triode region instead of the linear region.
Abstract:
An oscillation circuit includes a circuit for oscillation and a signal adjustment circuit connected to the circuit for oscillation. An input voltage based on a direct-current voltage, a voltage value of which can be changed, is input to the circuit for oscillation and the signal adjustment circuit. The circuit for oscillation causes a vibration piece to oscillate and outputs a first oscillation signal. A frequency of the first oscillation signal is adjusted according to the voltage value output from the signal adjustment circuit.
Abstract:
Adjusting a voltage-controlled oscillator (VCO) accurately and reliably. The voltage-controlled oscillator VCO attempts to generate an output signal with a programmed known frequency. An ALC circuit and a VCTA circuit adjust the VCO's amplitude and frequency. The system alternates making changes between amplitude or frequency, checking at each change what (difficult-to-predict) effect this has had on the output of the VCO. Each time the VCO switched capacitor array setting is changed, a circuit reviews the VCO output, and determines whether the VCO output should be adjusted in amplitude and frequency. The VCO amplitude and the VCO frequency are adjusted in alternating steps, that is, adjusting the VCO frequency, determining if further adjustments are desired, adjusting the VCO amplitude, determining if further adjustments are desired, and repeating until the VCO coarse adjustment has been sufficiently conducted.
Abstract:
An oscillation circuit includes a circuit for oscillation that oscillates a resonator, an output circuit that has a signal, output from the circuit for oscillation, input thereto to thereby output an oscillation signal, a connection terminal to which power is applied, a first wiring that connects from the connection terminal to the output circuit, and a second wiring that is connected to the first wiring through a connection node provided on the first wiring and connects from the connection node to the circuit for oscillation. The circuit for oscillation, the output circuit, the connection terminal, the first wiring, and the second wiring are provided on a semiconductor substrate. The length of a wiring extending from the connection terminal of the first wiring to the connection node is shorter than the length of the second wiring.
Abstract:
A circuit including a tank circuit, a pair of transistors, a bias circuit, and a capacitor. The transistors include (i) drain terminals coupled to the tank circuit, (ii) source terminals coupled to each other, and (iii) gate terminals cross-coupled to the drain terminals via a pair of capacitors. The bias circuit is coupled to the gates of the pair of transistors to i) alternatingly turn on the pair of transistors during a plurality of peaks of an oscillating signal of the tank circuit, and ii) turn off the pair of transistors during a plurality of crossing points of the oscillating signal. The capacitor is coupled to (i) the tank circuit and (ii) the pair of transistors.
Abstract:
A large gain is used to start up the oscillation of the crystal quickly. Once the oscillation starts, the amplitude is detected. A control circuit determines based on the measured amplitude to disable a low resistance path in the controlled switch array to reduce the applied gain below the power dissipation specification of the crystal. Another technique introduces a mixed-signal controlled power supply multi-path resistive array which tailors the maximum current to the crystal. A successive approximation register converts the amplitude into several partitions and enables/disables one of several power routing paths to the inverter of the oscillator. This allows a better match between the crystal selected by the customer and the on-chip drive circuitry to power up the oscillator without stressing the crystal. The “l/f” noise of the oscillator circuit is minimized by operating transistors in the triode region instead of the linear region.
Abstract:
Provided is a temperature compensated oscillator includes an oscillation circuit for oscillating an oscillator. In the oscillator, when an oscillation frequency is changed by a second control signal after being controlled by a first control signal, variation in the oscillation frequency due to a second control signal is set to a fixed amount. The oscillation frequency of the oscillator is controlled on the basis of both the first control signal and the second control signal, but an oscillation amplitude adjusting section is also added, the oscillation amplitude adjusting section allowing the oscillation amplitude of the oscillator to be changed by the second control signal. The oscillator thus allows a fixed amount of oscillation frequency control over a wide range (full range) of oscillation frequency control due to the first control signal.