Abstract: Disclosed is a voltage controlled oscillator which includes a first transistor in which a first terminal is connected to a first power supply, a body is connected to a gate, and a first output signal is output through a second terminal; a second transistor that is cross-coupled to the first transistor in such a manner that a first terminal is connected to the first power supply, a body connected to the second terminal of the first transistor is connected to a gate, and a second terminal is connected to the body of the first transistor, and that outputs a second output signal having an opposite phase to that of the first output signal through the second terminal; and a resonance filter in which a first terminal is connected to the second terminal of the first transistor and a second terminal is connected to the second terminal of the second transistor.

Abstract: A system for scalable voltage ramp control for power supply systems. A system may comprise at least power supply circuitry, digital-to-analog (D/A) converter circuitry and a controller. The power supply circuitry may be configured to output a voltage to a load based on an input voltage provided by the D/A converter. The controller may be configured to control the D/A converter (e.g., to cause the D/A converter to provide the input voltage to the power supply circuitry) using a large range voltage ramp-up or a small range voltage ramp-up. Utilization of the large range voltage ramp-up or the small range voltage ramp-up by the controller may be based on, for example, a threshold voltage.

Abstract: A power management apparatus and method for maintaining a substantially constant duty cycle of a reference clock signal in a multi-power oscillator, includes a first output power transistor in electrical parallel with a series arrangement of a second output power transistor and a switch, and a crystal oscillator capacitively coupled to a common gate of the first and second output power transistors, wherein a level of the reference clock signal power output is a normal power level when the switch is open and the level of the reference clock signal power output is a higher power level when the switch is closed to operate the second output power transistor in parallel with the first output power transistor.

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: An oscillation circuit section is provided which can attain the reduction of a consumed power amount and the reduction of a manufacturing cost. In a semiconductor device, voltages are generated to drive the oscillation circuit section by using a plurality of MOS transistors which are connected in serial and each of which is in a diode connection. At this time, each voltage is generated based on a power supply voltage and a ratio of the threshold voltages of the plurality of MOS transistors. Therefore, it is possible to suppress the threshold voltage of each MOS transistor, to save an area of each MOS transistor, and to reduce the consumed power amount of the oscillation circuit section.

Abstract: A voltage controlled oscillator module including a VCO unit and a gain adjustment unit is provided. The VCO unit is configured to generate a frequency signal based on a control voltage. The gain adjustment unit is coupled to the VCO unit and configured to receive a first adjustment voltage, a second adjustment voltage, and a reference voltage and accordingly adjusts the control voltage to adjust a frequency value of the frequency signal. The gain adjustment unit includes an adjustment circuit unit and a reference circuit unit. A first voltage-frequency curve of the frequency value of the frequency signal and a voltage value of the first adjustment voltage changes in response to a structure characteristic of the adjustment circuit unit. Furthermore, a frequency generating system and a method for adjusting a signal frequency of the VCO module are provided.

Abstract: An apparatus includes a microelectromechanical system (MEMS) device configured as part of an oscillator. The MEMS device includes a mass suspended from a substrate of the MEMS, a first electrode configured to provide a first signal based on a displacement of the mass, and a second electrode configured to receive a second signal based on the first signal. The apparatus includes an amplifier coupled to the first electrode and a first node. The amplifier is configured to generate an output signal, the output signal being based on the first signal and a first gain. The apparatus includes an attenuator configured to attenuate the output signal based on a second gain and provide as the second signal an attenuated version of the output signal.

Abstract: A built-in self-test circuit for testing a voltage controlled oscillator comprises a voltage controlled oscillator, a buffer having an input coupled to an output of the voltage controlled oscillator and a radio frequency peak detector coupled to the output of the buffer. The radio frequency peak detector is configured to receive an ac signal from the voltage controlled oscillator and generate a dc value proportional to the ac signal at an output of the radio frequency peak detector. Furthermore, the output of the radio frequency peak detector generates a dc value proportional to an amplitude of the ac signal from the voltage controlled oscillator when the voltage controlled oscillator functions correctly. On the other hand, the output of the radio frequency peak detector is at zero volts when the voltage controlled oscillator fails to generate an ac signal.

Abstract: An oscillator includes a reference voltage generator, an oscillation element configured to oscillate by either a drive voltage or a drive current and output an oscillation signal, a peak hold element configured to detect a peak level of the oscillation signal for output; and a controller configured to increase or decrease the drive voltage or drive current in accordance with the reference voltage generated by the reference voltage generator and the peak level output from the peak hold element.

Abstract: A self-powered power crystal oscillator XO includes a crystal unit and a power injection module. The crystal unit is arranged to oscillate to generate an oscillation signal. The power injection module is coupled to the crystal unit, and is arranged to intermittently inject energy to the crystal unit.

Abstract: A bias loop is used to program LC tank common mode voltage to allow operation at two different supply voltages VDD (e.g., 2.5V and 1.2V), and two different tank swings. This also allows lower phase noise through optimizing Ids shape allowing class C operation for both voltages. The two different supply voltages allow operation using multiple communication protocols such as 802.11n and 802.11ac within a common VCO circuit. The VCO can form part of a transceiver to provide frequencies in multiple bands.

Abstract: An apparatus includes a tank circuit of a voltage controlled oscillator. A pair of alternating current coupling capacitors respectively couple the gates of the pair of transistors to the drains of the pair of transistors. A bias circuit is coupled to the gates of the pair of transistors and biases the transistors in accordance with a bias voltage such that the transistors alternatingly turn on during a plurality of peaks of an oscillating signal of the tank circuit and the transistors turn off during a plurality of crossing points of the oscillating signal. A feedback loop may be configured to detect a peak oscillating amplitude of the oscillating signal and adjust a bias voltage of the bias circuit based on the peak oscillating amplitude. Also, a supply capacitor may be coupled to the tank circuit and to the transistors to provide an instantaneous current to the VCO.

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: An oscillator circuit generates a voltage signal. The magnitude of the voltage signal is measured and compared with predetermined upper and lower voltage signals by an internal test circuit. If the magnitude of the voltage signal is between the predetermined upper and lower voltage signals, then a pass test status signal is generated. If the magnitude of the voltage signal is not between the predetermined upper and lower voltage signals then a fail test status signal is generated.

Abstract: An oscillator circuit (702; 802) comprising first and second resonator terminals (710, 712; 810, 812) for connecting to respective terminals of a resonator (704; 804). The oscillator circuit also comprises a first inverting amplifier (706; 806) connected between the first and second resonator terminals (710, 712; 810, 812) in a first mode of operation; and a back to back pair of second inverting amplifiers (706, 708; 806, 808) connected between the first and second resonator terminals (710, 712; 810, 812) in a second mode of operation. There is also provided a controller configured to compare an operational parameter of the oscillator circuit (702; 802) to a switchover threshold, and switch the oscillator circuit (702; 802) from the first mode of operation to the second mode of operation when the operational parameter exceeds the switchover threshold.

Abstract: Oscillator circuits are disclosed herein. An embodiment of an oscillator circuit includes a first bias circuit and a second bias circuit. An oscillator first connection terminal is coupled to a node, wherein the node is coupled to the first bias circuit and the second bias circuit. An oscillator second connection terminal connected to the second bias circuit. An increase in the oscillation amplitude of the oscillator increases the current in the second bias circuit and causes a reduction in the bias current in the first bias circuit.

Abstract: Aspects include power supply systems. An error amplifier can generate an error voltage based on feedback associated with an output voltage to a reference voltage. A PWM generator can generate a PWM signal based on the error voltage. A power stage can generate the output voltage based on the PWM signal. The power stage can include a transconductance amplifier that generates a temperature-compensated sense current associated with a magnitude of an output current. An output voltage tuning circuit sets a desired magnitude of the output voltage based on at least one digital signal to adjust the reference voltage and the feedback voltage. An oscillator system generates a clock signal based on repeatedly charging and discharging a capacitor based on the clock signal and a comparator that compares the capacitor voltage and a second voltage having a magnitude that changes based on the state of the clock signal.

Abstract: A system and method for effectively performing a clock signal distribution procedure includes a clock generator configured to generate one or more clock signals that include electronic timing information. A clock load utilizes the electronic timing information from the clock signals to synchronize appropriate system processes. Capacitive coupling means are provided in a series configuration for transferring the clock signals from the clock generator to the clock load in accordance with an alternating-current direct-drive technique.

Abstract: An electrical, magnetic or electromagnetic delay line self oscillator is described with a delay line arrangement, an oscillator control circuitry, and a frequency selection impedance connecting the delay line arrangement and the oscillator control circuitry and presenting an impedance to the delay line arrangement. The oscillator control circuitry includes an amplifier, a non linear amplitude control element (N-LACE) such as an active device with a negative differential conductance that provides an output amplitude has a negative second derivative with respect to an input signal, and a driver. The modal characteristics of electromagnetic delay lines can thus be exploited across a wide range of instrumentation applications, and a means is provided to enhance the achievable functionality and/or performance of the instrumentation without the need for expensive additional electrical hardware or electronics.

Abstract: A method for generating an oscillator signal uses a multiphase oscillator having a plurality of input stages and a reference stage. Each input stage produces an input stage voltage that represents a phase for the oscillator. The input stage voltages produced by each of the input stages are compared to a reference voltage produced by the reference stage. An input stage having a maximum input stage voltage is selected and an output of the selected input stage having the maximum input stage voltage is changed. A current need of the oscillator is detected with a negative feedback loop coupled to the reference stage. An appropriate supply current is provided to each input stage with the negative feedback loop.

Abstract: A voltage-controlled oscillating circuit includes a differential amplifying circuit connected to a resonant element such as a quartz crystal element. The differential amplifying circuit includes first and second input terminals connected to the resonant element and also connected respectively to first and second voltage-controlled capacitors. The differential output terminals of the differential amplifying circuit are connected respectively to first and second emitter follower circuits. The output signal of the first emitter follower circuit is fed back to the second input terminal through a third capacitor and a third voltage-controlled capacitor, and the output signal of the second emitter follower circuit is fed back to the second input terminal through a fourth capacitor and a fourth voltage-controlled capacitor. A control voltage is applied to each of the voltage-controlled capacitors.

Abstract: A circuit device includes a current supply circuit adapted to supply an oscillation current, an oscillation circuit having an oscillation transistor for a resonator, and adapted to drive the resonator using the oscillation transistor based on an oscillation current from the current supply circuit, and a control section adapted to control the current supply circuit. If the oscillation circuit is set to an overdrive mode, the oscillation circuit drives the resonator with a higher drive power than the drive power in a normal mode.

Abstract: An improved local oscillator (LO) driver circuit for a mixer, the LO driver circuit includes a gain circuit responsive to response to LO input signals at a predetermined LO frequency range. At least a first pair of a parallel combination of a resistor and a capacitor is coupled to the gain circuit and to LO inputs of the mixer. The resistor configured to increase impedance at low frequencies of the frequency range and the capacitor is configured to reduce the impedance of the first parallel combination at high frequencies of the frequency range to reduce resistive impendence of the resistor. At least a second pair of a parallel combination of a low quality inductor and a high quality inductor is connected to the first pair. The second pair in serial combination with the first pair is tuned to provide a constant desired load impedance and a constant desired voltage swing at the LO inputs of the mixer over the predetermined LO frequency range.

Abstract: An oscillator circuit comprises a piezoelectric vibrator, an amplifier device including inverters provided in a plurality of stages, and an inverter control device. The inverters provided in the plurality of stages includes a performance-variable inverter configured which is operational in both of an initial phase of oscillation startup and a post-startup phase where the oscillation is stabilized and capable of a variable performance depending on whether the initial phase of oscillation startup or the post-startup phase where the oscillation is stabilized, and an ON/OFF inverter which is operational in the initial phase of oscillation startup and disconnected in the post-startup phase where the oscillation is stabilized.

Abstract: A gain control circuit, suitable for controlling the amplitude of a voltage-controlled oscillator, includes a duty cycle detector, an analog-to-digital converter, and a function generator. The gain control circuit provides a digitally enabled negative feedback loop. The duty cycle detector generates an estimate of the amplitude. The function generator receives a target amplitude as well as a digital representation of the estimate of the amplitude. The function generator calculates a modified estimate and periodically compares the same to the target value to generate a control word. The control word is arranged to enable current sources in the voltage-controlled oscillator.

Abstract: A Pumped Distributed Wave Oscillator (PDWO) that provides a high purity accurate signal source with multiple oscillation phases. High-accuracy, high-frequency oscillation phases open paths to high performance phased-array transceiver design. Additional noise-canceling, noise-shaping circuit techniques result in enhanced sensitivity in radio design.

Abstract: The present invention is a method for reducing phase noise in oscillator signals. For example, the oscillator may be a low phase noise MEMS-based oscillator and may include a resonator (ex.—a MEMS resonator). Further, the resonator of the oscillator may be operated near a bifurcation point. Still further, the MEMS resonator may be parametrically pumped in such a way so as to redistribute the quadrature signal noise (ex.—phase noise) to in-phase noise (ex.—amplitude noise).

Abstract: An oscillator having: (A) a transistor for producing an oscillating output signal at an output electrode of the transistor. The oscillator includes; (B) a bias circuit for producing a bias signal for the transistor, said bias circuit including an amplifier coupled to the output electrode of the transistor; and (C) a circuit coupled between an output of the amplifier and a control electrode of the transistor, for isolating the bias signal provided by the amplifier from the oscillating signal.

Abstract: An oscillator includes N greater than unity gain amplifiers, N being at least two. Each of the N greater than unity gain amplifiers has a pair of differential input terminals and a pair of differential output terminals. The oscillator further includes a first pair of variable resistances, N?1 pairs of variable resistances, N?1 pairs of variable capacitances, and a variable capacitance. The pairs of variable resistances couple differential output terminals of the N greater than unity gain amplifiers. The pairs of variable capacitances couple differential input terminals of the N greater than unity gain amplifiers. Each of the N greater than unity gain amplifiers includes a linearized operational transconductance amplifier stage coupled to a corresponding pair of the differential input terminals, and a unity gain buffer with feedback interconnected between the linearized operational transconductance amplifier stage and a corresponding pair of the differential output terminals.

Abstract: Noise immunity of an oscillator circuit is improved by either increasing the oscillation amplitude of the core's oscillating signal or configuring a built-in low pass filter.

Abstract: The present invention provides an oscillator and a communication system using the oscillator, in particular, an LC oscillator adapted to lessen phase noise deterioration due to harmonic distortions and increase the amplitude of oscillation, thereby having a favorable low phase noise characteristic. The oscillator comprises at least one voltage to current converter consisting of a transistor and a resonator comprising two LC tanks consisting of a pair of conductive elements and inductive elements. A feedback loop is formed such that an output terminal of the voltage to current converter is connected to the resonator and a current input to the resonator is converted to a voltage which is in turn fed back to an input terminal of the voltage to current converter. Inductive elements constituting the two LC tanks constituting the resonator are mutually inductively couple and a coefficient of the mutual induction is about ?0.6.

Abstract: Embodiments of the present invention provide an oscillator having circuitry that measures the power dissipated in a resonator and circuitry that controls the power delivered to the resonator in response to the measured power. In some embodiments, the circuitry that measures the power dissipated in the resonator comprises circuitry that measures the voltage across the resonator, circuitry that measures the current through the resonator, and circuitry that calculates the power dissipated in the resonator based on the measured voltage and current.

Abstract: A method, an apparatus and/or a system of injection locking based power amplifier is disclosed. A method includes inputting a reference signal through an injection circuit of an oscillator circuit that generates an output signal of high power that oscillates at an inherent frequency of oscillation of the oscillator circuit. The method also includes reducing a frequency of the reference signal through a differential transistor pair coupled to the injection circuit of the oscillator circuit. The method further includes locking through a tuning circuit of the oscillator circuit coupled to the differential transistor pair a frequency of the output signal to the reduced frequency of the reference signal based on the power of the reference signal to amplify the power of the reference signal through the oscillator circuit. The frequency of the reference signal is higher than the frequency of the output signal.

Abstract: An amplitude control circuit includes a pair of peak detectors. The pair of peak detectors are responsive to a voltage reference generator. The amplitude control circuit is configured to be responsive to an oscillating signal of a crystal oscillator and configured to generate a control signal to control an amplitude of the oscillating signal.

Abstract: An oscillator and a control circuit thereof are provided. The control circuit is configured to control an oscillator to adjust the amplitude and the level of an oscillation signal. The control circuit includes a peak amplitude detector, an average voltage detector, and an oscillation controller. The peak amplitude detector is configured to detect the amplitude of the oscillation signal, so as to generate an amplitude value. The average voltage detector is configured to detect the direct current (DC) level of the oscillation signal, so as to generate an average value. The oscillation controller is configured to generate two power signals according to the amplitude value and the average value. The two power signals are provided to the oscillator, so that the oscillator adjusts the amplitude and DC level of the oscillation signal.

Abstract: A voltage-controlled oscillating circuit includes a differential amplifying circuit connected to a resonant element such as a quartz crystal element. The differential amplifying circuit includes first and second input terminals connected to the resonant element and also connected respectively to first and second voltage-controlled capacitors. The differential output terminals of the differential amplifying circuit are connected respectively to first and second emitter follower circuits. The output signal of the first emitter follower circuit is fed back to the second input terminal through a third capacitor and a third voltage-controlled capacitor, and the output signal of the second emitter follower circuit is fed back to the second input terminal through a fourth capacitor and a fourth voltage-controlled capacitor. A control voltage is applied to each of the voltage-controlled capacitors.

Abstract: An amplifier circuit for amplifying output signal from the crystal oscillator circuit is connected to the output side of the crystal oscillator circuit. The amplifier circuit amplifies the difference between the output voltage of the crystal oscillator circuit and the input voltage of a CMOS inverter of the crystal oscillator circuit. For example, a differential amplifier is connected to the output side of the crystal oscillator circuit, then the output voltage of the crystal oscillator circuit and the input voltage of the CMOS inverter are connected to the inputs of the differential amplifier.

Abstract: A circuit for a voltage controlled oscillator (VCO) buffer is described. The circuit includes a first capacitor connected to an input of the VCO buffer that is connected to a VCO core. The circuit also includes a second capacitor connected to the input of the VCO buffer and the gate of a p-type metal-oxide-semiconductor field effect (PMOS) transistor. The circuit further includes a first switch connected to the first capacitor and the gate of the PMOS transistor. The circuit also includes a third capacitor connected to the input of the VCO buffer. The circuit further includes a fourth capacitor connected to the input of the VCO buffer and the gate of an n-type metal-oxide-semiconductor field effect (NMOS) transistor. The circuit also includes a second switch connected to the third capacitor and the gate of the NMOS transistor.

Abstract: An oscillator includes oscillator circuitry (8) including a transconductance stage (2) and a resonator (3). A comparator (10) produces first (CLK) and second (/CLK) clock signals which indicate the timing of positive and negative phases of a differential output signal (VIN+-VIN?) produced by the transconductance circuit in response to the resonator. A synchronous rectifier (14) converts the differential output signal to a current (IRECT) in response to the first and second clock signals. A switched capacitor notch filter (15) filters the current in response to the first and second clock signals. A control current (ICONTROL) which controls the transconductance of the transconductance circuit is generated in response to the notch filter. The resonator may be a MEMS resonator.

Abstract: According to one embodiment, an oscillator circuit includes a first comparator circuit, a second comparator circuit, a first voltage control circuit, a second voltage control circuit, a clock generation circuit. The first comparator circuit is configured to compare a first voltage with a first threshold voltage to generate a first comparison result. The second comparator circuit is configured to compare a second voltage with a second threshold voltage to generate a second comparison result. The first voltage control circuit is configured to decrease the first voltage by a first voltage value in synchronization with timing when the first comparison result changes. The second voltage control circuit is configured to decrease the second voltage by a second voltage value in synchronization with timing when the second comparison result changes.

Abstract: Noise immunity of an oscillator circuit is improved by either increasing the oscillation amplitude of the core's oscillating signal or configuring a built-in low pass filter.

Abstract: In a logical element, supporting portions, and a beam supported by them at two ends are formed. The beam has a back side surface spaced apart from the top side surface of a substrate, creating a space between the facing surfaces of the beam and substrate. An excitation electrode is formed on one supporting portion, whereas an oscillation detecting electrode is formed on the other supporting portion.

Abstract: Apparatus and methods are provided for oscillators having adjustable gain. An exemplary oscillator module comprises a first node for a first voltage, a control node for a control signal, and oscillator circuitry coupled to the first node and the control node. The oscillator circuitry generates an output signal with a first oscillation frequency based on the first voltage, and in response to the control signal being asserted, the oscillator circuitry generates the output signal with a second oscillation frequency based on the first voltage. The second oscillation frequency is greater than the first oscillation frequency.

Abstract: A circuit and method for calibrating a VCO (voltage controlled oscillator) is disclosed. In one embodiment, a circuit includes a VCO and a bias control circuit coupled to a tail node of the VCO. An amplitude control unit may also be coupled to the tail node, wherein the amplitude control unit is configured to determine the amplitude of a VCO output signal based on a voltage present on the tail node. The amplitude control unit may also be configured to generate a bias voltage based on the amplitude of the VCO output signal and a target voltage. The bias control circuit may be coupled to receive the bias voltage from the amplitude control unit and may be further configured to adjust the voltage on the tail node based on the received bias voltage.

Abstract: The fundamental breakthrough in green technology are the Varactor Free Amplitude Controlled Oscillator VFACO and the planar EMI-Free Planar Inductor. The VFACO makes the fine tune for oscillation frequency. It has the frequency compensation over temperature. It doesn't have the VCO self-modulation-induced phase noise. It is phase-noiseless. It is high-Q and high stability. It increases the communication capacity. The EMI-Free Planar Inductor is the backbone of the platform of green technology. The platform of green technology contains the Xtaless ClockChip, Inductorless PMU & PA and ESDS-PCB to provide the green technology for green chip design. Especially for the 4th generation wireless communication, the Inductorless PMU & PA are the most important green technology. The Xtaless ClockChip adopts the most advanced self-compensation Amplitude controller. The ESDS-PCB has the minimum Via assignment algorithm to make the optimum pin assignment for the platform of green technology.

Abstract: An electrical, magnetic or electromagnetic delay line self oscillator is described with a delay line arrangement, an oscillator control circuitry, and a frequency selection impedance connecting the delay line arrangement and the oscillator control circuitry and presenting an impedance to the delay line arrangement. The oscillator control circuitry includes an amplifier, a non linear amplitude control element (N-LACE) such as an active device with a negative differential conductance that provides an output amplitude has a negative second derivative with respect to an input signal, and a driver. The modal characteristics of electromagnetic delay lines can thus be exploited across a wide range of instrumentation applications, and a means is provided to enhance the achievable functionality and/or performance of the instrumentation without the need for expensive additional electrical hardware or electronics.

Abstract: Apparatuses and methods are provided relating to a voltage controlled oscillator (VCO) based on current starved inverting delay stages; wherein in each stage a PMOS transistor as header and an NMOS transistor as footer are used with their gate-to-source voltages always equal to analog control voltage. The analog control voltage is also used as the supply voltage of the oscillator. An exemplary apparatus includes a VCO of n stages, where n is an odd number and where each stage includes a current starved inverter where the analog control voltage is also used as the supply voltage of each delay stage.

Abstract: A voltage-controlled variable frequency oscillation circuit, includes: an oscillation circuit section including a resonance circuit which includes a coil and a variable capacitance element, and a negative resistance circuit; and a first resistor connected between the oscillation circuit section and a first one of a pair of terminals of a power supply.

Abstract: An adaptive demodulator for a contactless device, including a rectifier configured to rectify a voltage which is dependent on a signal received by the contactless device, and a voltage regulator coupled to the rectifier and configured to adjust the voltage to be within a voltage window.

Abstract: There is provided an oscillator circuit including: a current source; a resonant unit; an oscillation amplification unit connected to the current source and connected in parallel to the resonant unit; a feedback resistor connected in parallel to the oscillation amplification unit; a switch unit having a first end connected to the current source side of the oscillation amplification unit; a replica circuit connected between a second end of the switch unit and a ground side of the oscillation amplification unit and having a configuration identical to a configuration of the oscillation amplification unit; and a level detecting unit that detects an input voltage of the oscillation amplification unit, and, when the detected input voltage is higher than a bias voltage level at a time of oscillation, cause the switch unit to allow a current from the current sources to bypass through the replica circuit.