Abstract: An integrated circuit voltage-controlled oscillator includes an amplifier, a low Q LC resonator coupled to the amplifier, and a voltage-controlled variable delay element connected to delay feedback between an output and an input of the amplifier.

Abstract: An interleaved, tunable ring oscillator is disclosed that produces more output phases without resorting to interpolation. The oscillator is inherently symmetrical and suffers from none of the systematic time errors of an interpolator approach. The oscillator stages are interconnected to allow the oscillating frequency to be higher than the conventional limit of 1/(2*N*T.sub.D). Frequency tuning is accomplished by electronically varying the delay of each stage of the ring oscillator. A mixer cell performs a weighted sum of a first input and a second delayed input. The delay ranges from the delay of the mixer itself to the sum of the delays of the mixer and the delay cell.

Abstract: An oscillator circuit includes biasing branches in the input section for permitting the oscillator gain and center frequency to be easily adjusted depending on design requirements. Accordingly, the oscillator circuit can be designed so as to have a lower overall gain and bandwidth yet operative at desired high frequencies. An output section includes a high-swing cascode current mirror for rejecting noise perturbations on the power supply so that they do not enter the oscillator stage, thus reducing jitter in the PLL frequency. The output section can be biased by a current mirror section so as to feed back an output voltage to one of the biasing branches of the input section, further lowering the overall gain and bandwidth of the oscillator circuit.

Abstract: An emitter-coupled multivibrator circuit including a pair of main transistors (Q1,Q2) having a positive feedback, in which the base of each transistor is connected to the collector of the other transistor. A capacitor (C) is connected between the emitters of the main transistors. The circuit further comprises pull-down transistors (Q3,Q4), cross-connected so that they are positively driven to alternate between a conducting and a non-conducting state according to the states of the main transistors. The frequency of the oscillator is adjusted by controlling the current (Icon) passing through the capacitor (C). Additionally, a compensating current (I2) is arranged to flow through the collector resistors (Rc1,Rc2) of the main transistors so that the total current passing through each resistor is essentially constant and independent of the control current (Icon). This way the signal amplitude of the oscillator is not affected by the frequency control.

Abstract: A multistage voltage-to-current ("VI") converter for producing, in response to an input voltage, an output voltage useful for controlling a voltage-controlled oscillator ("VCO"). Preferably, the transfer function of the VI converter is such that the output clock frequency-to-input voltage transfer function (of a system including the VI converter and the VCO) is at least approximately linear over a desired output clock frequency range and has a desired slope in such range. In preferred embodiments, the multistage VI converter includes three differential amplifier stages connected in parallel. Each stage has a tail current and receives a reference voltage (the tail currents and reference voltages typically differ from stage to stage), and produces a component of a total current. The total current determines the output voltage. Optionally, bias circuitry is provided for producing nonzero output voltage in response to zero input voltage.

Abstract: A voltage controlled oscillator comprising: a ring of inverters comprised of an odd number of serially connected CMOS inverter stages, the inverter stages being connected between first and second oppositely poled power leads, a MOSFET having a source-drain circuit connected between one of the power leads and a first power rail, the other power lead being connected to a second power rail, apparatus for operating the MOSFET in saturation, and apparatus for applying a control voltage to the gate of the MOSFET, referenced to the second power lead, whereby the MOSFET operates as a nonlinear current conduction device having a characteristic such as to linearize the voltage-frequency characteristic of the combined MOSFET--ring oscillator combination.

Abstract: An optically controlled oscillator utilizes a HEMT or a PIN diode as a photodetector and either a HEMT or HBT as an active inductor. The optically controlled HEMT active inductor provides a means for tuning the frequency of the oscillator. The optical receiver includes an optically tunable active inductor using a photodetector which includes a resonant tank circuit of an electronic oscillator to allow both optical/digital quench and unquench of an oscillator or digital AM detection with an improved signal to noise ratio, or optical FM modulation and analog AM detection by tuning/shifting the frequency of the oscillation through the detection of the optical light intensity.

Abstract: An apparatus and method for providing a variable frequency clock source is described wherein the frequency may be changed while maintaining the phase of the clock signal. A frequency conversation circuit, such as a phase locked loop (PLL), is employed to change the frequency of the clock and is controlled by a control unit which maintains the phase of the output clock signal while undergoing a frequency change operation.

Abstract: A programmable frequency synthesizer comprised of a phase locked loop (PLL) including a current controlled oscillator (ICO), a level translator for receiving output signals from the ICO wherein the output signals have a finite slew rate, a reference source of signals, a phase-frequency detector for receiving signals from the reference source and output signals generated by the level translator and for providing pulse signals to the ICO having pulse widths which are directly proportional to phase difference between the signals from the reference source and the output signals from the level translator, and apparatus for varying the slew rate of the output signals from the ICO wherein the duty cycle and thus the frequency of output signals of the level translator may be varied.

Abstract: A regulating circuit for a quartz crystal oscillator-based timepiece is capable of compensating for large deviations in oscillation frequency of the quartz crystal oscillator. A frequency divider sequentially divides the reference clock by one-half. A regulation data setting circuit sets logical regulation data used to compensate for deviations in the oscillation frequency of the oscillator from a desired value. A regulation circuit adjusts the frequency dividing ratio of the frequency dividing circuit based on the logical regulation data in accordance with a predetermined cycle and controls in such a manner that the frequency of a divided output signal of the frequency divider has a predetermined frequency. When the frequency of the divided output signal cannot coincide with the predetermined frequency using the set logical regulation data, the range of adjustment is shifted using data set in a switch during production of the timepiece.

Abstract: An improved voltage controlled oscillator circuit is based on a multivibrator design with an internal gain stage to permit low voltage operation. An internal gain stage maintains a loop gain of greater than one to ensure oscillation even at power supply voltages as low as 2.7 volts. The added gain allows the use of resistors inserted on either sides of a timing capacitor for improved linearity.

Abstract: A multi-octave ferrite oscillator topology that utilizes transformer coupling to provide the proper phase shift in the feedback loop. In a specific embodiment, a 10 mil YIG sphere is loosely coupled to 20 mil input and output loops, both of which are connected to a GaAs integrated circuit that includes a Darlington pair of bipolar transistors. The Darlington pair provides high gain, high output power, and low parasitic reactance up to about 10 GHz. A resistor bridge across the base of the input transistor of the Darlington pair insures a substantially real input impedance over a wide bandwidth.

Abstract: A microcontroller circuit having firmware selectable oscillator trimming includes, in combination, a microcontroller, an oscillator located within the microcontroller for providing a system clock signal for the microcontroller, and a memory portion for providing trimming data to the oscillator for trimming frequency of the system clock. The microcontroller circuit includes microcontroller logic which has the trimming data stored therein for transfer to the memory portion. Additionally, the microcontroller logic permits the user to alter the trimming data after it has been transferred to the memory portion, thereby permitting the user to alter the amount of modification of the system clock frequency from the amount associated with the trimming data.

Abstract: A delay interpolating voltage controlled oscillator (VCO) is provided. The delay interpolating VCO includes an input for receiving differential control input. A non-linear current steering circuit is coupled to the input for generating a non-linear delay responsive to the differential control input. A frequency signal is provided at a VCO output responsive to the differential control input and the non-linear delay with the frequency signal being linearly related to the differential control input.

Abstract: A phase locked loop including a comparator, a VCO controller, and a VCO having a multi-stage oscillator portion and a combinational logic portion. The comparator is responsive to an input clock and a VCO comparison clock and is operative to produce a comparator output signal. The VCO controller is responsive to the comparator output signal and is operative to produce a VCO control signal. The multi-stage oscillator portion is configured to oscillate at a VCO clock frequency during a steady state condition under the control of the VCO control signal, and is further operative to develop a plurality of clock phases at the VCO clock frequency. The combinational logic portion is responsive to at least some of the plurality of clock phases and is operative to combine clock phases to create an output clock having an output clock frequency that is a multiple of the input clock frequency.

Abstract: A voltage controlled oscillator is capable of rectilinearly changing an oscillation frequency over a wide range while keeping, to a fixed value, a signal amplitude of a ring oscillator using an differential amplifier by eliminating dependency of the signal amplitude upon a tail current. A load resistor section of each delay element is constructed of a variable resistor element for changing a differential output current flowing corresponding to variations in tail current, and a clamp circuit for fixing the amplitude of an output terminal of the delay element.

Abstract: A frequency modulator controls the center frequency and modulation factor at the same time with one control signal. The frequency modulator includes a voltage-to-current converter that receives an input voltage signal to be modulated, a reference voltage signal, and a control voltage signal, and generates an output current signal by combining the input voltage signal and the control voltage signal. The input voltage signal is amplified by a transconductance amplifier. The control voltage signal is converted into a gain signal which is used to vary the transconductance of the amplifier. A voltage controlled oscillator generates a frequency modulated signal responsive to the output current signal. The center frequency and modulation factor can be controlled by adjusting the value of a resistor in the current-to-voltage converter, a capacitor in the voltage control oscillator, or the control voltage signal.

Abstract: A circuit for suppressing period jitter of the clock output of a ring oscillator caused by supply voltage fluctuations. The ring oscillator includes n identical current controlled delay circuits 26.1-n connected in a ring, and a replica circuit 36 identical to the current controlled delay circuit. The replica circuit 36 receives a constant input voltage so that its output is always at a high level. A differential amplifier 35 receiving a reference potential Vref is connected in a negative feedback circuit with replica circuit 36, so that the output of the replica circuit 36 is held equal to the reference potential Vref. An output of the negative feedback circuit is also applied to each of the current controlled delay circuits 26.1-n, so that their high level outputs are held equal to the reference potential Vref.

Abstract: The present invention provides for a voltage-controlled crystal oscillator (VCXO) which, other than the crystal itself, is full integrated. The VCXO has a pre-amplifier block, a gain stage, a first MOS transistor, a first capacitor, a second MOS transistor, and a one second capacitor. The pre-amplifier block receives an input tuning voltage and the gain stage is connected across the terminals of the oscillating crystal. The first MOS transistor and first capacitor are connected between one of the terminals of the oscillating crystal and a reference voltage. The second MOS transistor and the second capacitor are connected between the second crystal terminal and the reference voltage. The gates of both MOS transistors are connected to the output node of the pre-amplifier block. The first and second MOS transistors connect the first and second capacitors to the first and second terminals of the gain stage for a portion of the time responsive to the input tuning voltage.

Abstract: A voltage controlled oscillator (VCO) having a current source and a process dependent (or process controlled) impedance is disclosed. The voltage controlled oscillator includes a current mirror that generates a reference current in response to a control current. The reference current is proportional to the control current. The process dependent impedance, which is coupled to the current mirror, compensates the reference current to account for process variations in the manufacture of the (VCO) circuit.

Abstract: A transmitting and receiving apparatus configured in superheterodyne form, includes a receiving circuit for receiving a signal on one channel of a predetermined pair of channels and a transmitting circuit for transmitting a signal on the other channel of the predetermined pair of channels. The receiving circuit has a first voltage-controlled oscillator including a first oscillating transistor and generating a local oscillated signal used for receiving the signal on one of the channels, and a first current control means for controlling a collector current of the first oscillating transistor. The transmitting circuit has a second voltage-controlled oscillator including a second oscillating transistor and generating a signal of the frequency of the other channel, and a second current control means for controlling a collector current of the second oscillating transistor.

Abstract: A voltage controlled-oscillator ring oscillator having an adjustable high-frequency reference and an adjustable low-frequency reference. A mixer and a plurality of delay elements comprise a delay interpolating oscillator ring. The mixer receives a high-frequency reference input signal from a first multiplexer which selects the output of one of several delay elements having relatively short delay loop paths. The mixer receives a low-frequency reference input signal from a second multiplexer which selects the output of one of several delay elements having relatively long delay loop paths. The frequency of the mixer output is continually adjustable between the high-frequency reference and the low-frequency reference. As operating conditions change the first and second multiplexers can select the outputs of different delay elements in order to change the frequency of the high-frequency and low-frequency references.

Abstract: A voltage controlled oscillator (VCO) having a generally linear transfer characteristic across a wide frequency range of operation. The VCO is comprised of a voltage-to-current converter (V-I) and a current-controlled oscillator (ICO). A linearization of the output response of the VCO is accomplished by proper selection of the output responses of the V-I and ICO circuits, where the V-I portion is designed to have an inverse nonlinearity response as compared to the nonlinearity response of the ICO portion of the VCO. The combined effect is a linear response for the VCO. A nonlinear V-I characteristic can be achieved by adding several piecewise linear responses together to produce a combined nonlinear response.

Abstract: A voltage controlled oscillator (VCO) having a current gain compensation circuit includes a control circuit portion for generating a frequency control signal, and a ring oscillator responsive to the frequency control signal for outputting the VCO output signal. The control circuit includes a control transistor responsive to input control voltage V.sub.control. Connected between the source terminal of the control transistor and ground is a resistive element in parallel with an N-channel field effect transistor and a P-channel field effect transistor, each configured to operate in saturation. The resistor, and the N-channel, and P-channel transistors provide parallel current paths which, collectively, form a control current that corresponds to the frequency control signal. As the voltage control signal V.sub.control increases beyond a predetermined level, the transistors conduct, and carry a current that is proportional to the square of the input control voltage V.sub.control.

Abstract: An apparatus and a method are provided to obtain oscillations from a crystal at a particular frequency by introducing real and imaginary components of voltage to the crystal. The imaginary component of voltage is different from the real component of voltage by a particular phase angle such as 90.degree.. The voltage introduced to the crystal is processed to produce a first current having characteristics corresponding to such voltage and to produce a second current having characteristics related to the imaginary component of such voltage. The first and second currents are combined to produce a first current corresponding to the real component of the voltage introduced to the crystal. This current is shifted through a phase angle of 90.degree. to produce a second current corresponding to the imaginary component of the voltage introduced to the crystal. The first current is converted to a first voltage which is regulated to provide a particular gain.

Abstract: The high frequency circuit includes an oscillator connected in a Colpitts configuration. Negative feedback to the oscillator is applied through an amplifier, both to stabilize the circuit and to permit frequency modulation of the carrier signal generated by the circuit. This feedback incorporates a capacitance to neutralize the Miller effect, thereby enabling it to operate at exceedingly high carrier frequencies. A variation of the circuit permits it to be simultaneously controlled by both a voltage and a current control signal. Also, by applying a frequency modulated carrier signal at a particular node of the oscillator, a demodulated output signal may be obtained.

Abstract: A digital temperature compensated crystal oscillator (10) with pin multiplex control which includes: four analog I/O pins, a signal multiplex method which allows switchable digital communication via at least two of the analog I/O pins (20,28), and an external mode selector (12) which operates through the power leads. Changes in the power voltage level selects the TCXO (10) to operate in a normal or communication operating mode. In the normal operating mode the TCXO operates in a normal analog manner. In the communication mode, the analog functions of the I/O pins (20,28) are switched out and digital functions are allowed on the same I/O pins (20,28). The use of the same I/O pins (20,28) for switchable analog and digital signals saves size and cost, and prevents the inadvertent access to the digital functions of the TCXO (10) by customers in the field.

Abstract: A voltage-controlled oscillator includes at least one voltage-controlled delay element and a reference voltage generator. The voltage-controlled delay element has first and second voltage supply inputs, a control voltage input, a signal input and a signal output. The reference voltage generator has a voltage input coupled to the control voltage input and a voltage output coupled to the first voltage supply input.

Abstract: A quadrature oscillator includes an amplitude control circuit that is based upon the trigonometric identity sin.sup.2 .omega.t+cos.sup.2 .omega.t=1. The amplitude control circuit, referred to as a Pythagorator, includes two squaring circuits. Each squaring circuit receives a respective quadrature oscillator signal and squares it. The outputs of the two squaring circuits are joined together so as to sum the outputs of the two squaring circuits to produce a sum of squares signal. This signal, a current in the preferred embodiment, is provided to damping diodes coupled to the outputs of the quadrature oscillator. The damping diodes produce a shunt positive resistance at the outputs of the quadrature oscillator in response to this current that has the effect of cancelling the shunt negative resistance of the regenerative elements of the oscillator thereby establishing the amplitude of the quadrature oscillator signals at a desired amplitude.

Abstract: An oscillation circuit is provided which is easily adjusted with a high degree of accuracy. The oscillation circuit including a filter having a time constant and an inverting amplifier which feeds back the output of the filter to the input side of the filter so that an oscillation condition is fulfilled. The filter includes a gm amplifier formed of a differential amplifier, and a capacitor. The constant current source of the differential amplifier is connected to a free running oscillation frequency adjusting circuit. The adjusting circuit includes a microcomputer, a decoder which decodes the output data of the microcomputer and a switching circuit driven by the output of the decoder and varying the current value according to the output of the decoder. A current in accordance with a current value depending on the setting of the switch flows through the constant current source.

Abstract: An oscillating signal generator for generating an oscillating signal having a variable oscillation frequency that can be near the unity gain frequency of the gain devices within the oscillating signal generator (Generation of High-Frequency Oscillating Signal Techniques, "GHOST"). Two gain stages, each with a respective effective resistance R.sub.eff, an emitter load capacitance C.sub.E, and a respective gain device having a unity gain frequency .omega..sub.T, are cascaded and configured to provide a respective gain with a phase at substantially 180.degree.. In that case, the oscillation frequency, of the oscillating signal generated by the oscillating signal generator of the present invention, .omega.=?.omega..sub.T /(R.sub.eff C.sub.E)!.sup.1/2. A feedback with a feedback gain is provided between the output to the input of the cascade of the two gain stages. The feedback gain is designed such that a product of the feedback gain and the gain through the cascade of the two gain stages is substantially one.

Abstract: A voltage controlled oscillator has a linear voltage to current characteristic from ground to the supply voltage. This oscillator includes a voltage to current converter which employs two output current paths. The first output current path includes an N-type MOSFET whose gate receives the input voltage. A level shifter circuit receives the input voltage and provides an output voltage shifted up by an amount equal to the input threshold voltage of an N-type MOSFET. A clamp circuit connected to the output of the level shifter circuit prevents this output voltage from becoming greater than a voltage equal to the sum of the input threshold voltage of an N-type MOSFET and the input threshold voltage of a P-type MOSFET. The gate of the second N-type MOSFET receives the output of the level shifter as clamped by the clamp circuit. A current mirror circuit supplies a current control to ring oscillator, whose frequency depends upon the current. A second embodiment includes a new ring oscillator.

Abstract: A dual voltage controlled oscillator including a transistor with a negative differential resistance diode coupled to a first terminal and an inductance coupled to a second terminal. Operating voltages are applied to the gate and drain of the transistor to set the oscillator to operating in a negative differential resistance region of the diode. The diode, the inductance and the operating voltages are connected so that varying either of the operating voltages varies the frequency of the oscillations at the output.

Abstract: This invention provides a temperature-compensated piezoelectric oscillator having an oscillation frequency that is easily adjusted in an adjustment procedure after its assembly. Compensation for frequency-temperature characteristics is achieved without the need for an externally installed variable reactance element. The temperature-compensated piezoelectric oscillator includes a piezoelectric oscillator element and an oscillator circuit that drives the piezoelectric oscillator element. The oscillator circuit changes the oscillation frequency in response to an applied power supply voltage VDD(T). A temperature sensor circuit senses the ambient temperature T of the piezoelectric oscillator element. A variable power supply circuit changes the power supply voltage VDD(T) applied to the oscillator circuit in response to the temperature sensed by the temperature sensor circuit. The changes in the applied power supply voltage VDD(T) changes the frequency-temperature characteristics of the oscillator circuit.

Abstract: An improved timer oscillation circuit capable of synchronizing an oscillation frequency, which is determined by a time constant of a resistance and a capacitance, to a clock signal, which includes a first voltage comparator, controlled by a clock signal, for charging a first voltage on a second capacitance and for outputting a result obtained by comparing the charged voltage on the second capacitance and a voltage from the first capacitance; and a second voltage comparator, controlled by the clock signal, for charging a voltage outputted from the first capacitance on a third capacitance and for outputting a result by comparing the charged voltage and an electric potential of the second voltage, so that it can be advantageously adopted to a digital circuit by outputting an oscillation signal having a cycle determined by a time constant of a resistance and a capacitance and which is synchronized to a clock signal.

Abstract: A circuit arrangement is indicated to generate a clock frequency for a data transmission system by using a voltage-controlled fundamental wave quartz oscillator (VCXO), whose frequency can be changed within narrow limits as a function of the control voltage. To double the frequency of the fundamental wave quartz oscillator (VCXO), its output (A) is connected to the input of a rectifier bridge circuit (1) having an ohmic resistance (2) placed at its output. The ohmic resistance (2) is connected to both inputs of a comparator (3), and the clock frequency (f) is present at the output of the comparator.

Abstract: A monolithic CMOS phase-lock loop (PLL) circuit provides a high frequency of operation suitable for RF applications. The PLL produces an output clock with high spectral purity and very low jitter. The output clock has a low static phase error relative to a reference input, making the PLL useful for clock synchronizing applications, such as clock recovery elements in transmission/recording channels. The PLL provides in-phase and quadrature signals from a voltage controlled oscillator (VCO) which has two differential transconductors. The second differential transconductor has a positive input coupled to a positive output of the first differential transconductor, a negative input coupled to a negative output of the first differential transconductor, a positive output coupled to a negative input of the first differential transconductor, and a negative output coupled to a positive input of the first differential transconductor. Each differential transconductor has a negative output impedance.

Abstract: A ring oscillator comprising an odd number of inverters connected in a ring, and apparatus for driving the ring oscillator so that it oscillates at a frequency slightly less than its maximum oscillating frequency such that harmonics of the oscillating frequency are suppressed.

Abstract: A voltage controlled ring oscillator having a reduced voltage controlled oscillator (VCO) gain by controlling only the fall time of the period of the VCO using integrated circuits and logic circuits. The VCO includes a mixer/inverter circuit, a logic circuit, a delay/inverter circuit, a first delay circuit, a second delay circuit, and a third delay circuit. The VCO gain is reduced by controlling only one pulse width of the logic level High and one pulse width of the logic level Low of the oscillating period. Furthermore, the VCO can be logically controlled by using a simple logic circuit as a component of the VCO.

Abstract: A voltage-controlled oscillator comprises a plurality of delay circuits connected in a ring configuration. Each of the delay circuits comprises a current source and a differential pair of inverting circuits each supplied with current from the current source. Each of the differential pair of inverting circuits consists of a P-type MOS transistor and an N-type MOS transistor having a drain connected to the drain of the P-type MOS transistor. When a control voltage equal to or higher than the threshold voltage of each N-type MOS transistor is applied to the gate thereof, the voltage at the drain of each P-type MOS transistor oscillates at a frequency corresponding to the control voltage, since each N-type MOS transistor exhibits a linear current characteristic with respect to the control voltage.

Abstract: An oscillator is provided having a plurality of cascade coupled inverters Each one of the inverters is a differential amplifier having a p-input and an n-input. The output of each one of the amplifiers is connected to: the n-input of the next succeeding amplifier to provide a closed loop, or ring oscillator; and, the p-input of an amplifier positioned an even number of amplifier stages forward of such next succeeding amplifier. In a preferred embodiment, each amplifier in the ring includes an n channel transistor (nMOS transistor) connected in a totem pole arrangement, to a p channel transistor (pMOS transistor). The gate of the nMOS transistor provides the n-input and gate of the pMOS transistor provides the p-input. The source and drain paths of the pMOS and nMOS transistors are connected together to provide an output for the amplifier.

Abstract: A voltage controlled oscillator module (100) (400) provides tuning capability for the VCO in a shielded environment. The module includes a trimmable capacitor (110) (410) having metal plates (112, 114), (412, 414, 416) capacitively coupled through the substrate. One of the metal plates (114) (416) is a trimmable plate which can be trimmed to tune the VCO frequency. The trimmable metal plate (114) (416) remains exposed on the bottom surface (108) (408) of the substrate (104) (404) so that the frequency of the VCO can be tuned while the reminder of the oscillator circuitry (102) (402) on the top surface (106) (406) is encapsulated by a ground shield (116) (418).

Abstract: A relaxation oscillator of reduced complexity is described which can be constructed as part of a silicon integrated circuit. The current controlled oscillator includes complementary field effect transistors operating in enhancement mode. The drain of one FET is connected to the gate of the other FET and vice versa. The resulting CMOS circuit functions as a four-layer diode. A resistor is connected between the drains of both transistors. A storage capacitor is connected between the sources of both transistors. A current source is connected to charge the storage capacitor such that the frequency of an oscillator output signal is determined by the current generated by the current source.

Abstract: A monolithically integrated oscillator is implemented as ring oscillator with a line driver and a double line formed on one and the same chip. A running time of the double line is selected optimally long and a delay time of the line driver is selected optimally short. The double line can be loaded with controllable capacitors.

Abstract: A voltage controlled oscillator having substantial frequency dependence on a parallel RC timing element including a voltage-variable resistance element, such as a MOSFET biased in the triode region. One terminal of the timing element can be connected to ground. The voltage used to tune the timing element, to lock the voltage controlled oscillator to a reference frequency can be used to control similar timing elements integrated upon the same circuit, for example a continuous-time filter in an ethernet transceiver. The oscillator frequency is substantially independent of variations in supply voltage.

Abstract: A PLL based microprocessor whose frequency may be adjusted by using a microprocessor clock control circuit. The microprocessor clock control circuit comprises a circuit for providing a slew rate limited overdampened PLL that continuously seeks a new frequency, a circuit for selecting a current target frequency for the microprocessor, a circuit for comparing the current target frequency to the current frequency setting of the microprocessor, and a circuit for adjusting the current frequency setting of the microprocessor to match the current target frequency.

Abstract: An electrical signal generator for generating an output signal of predetermined frequency has an oscillator of predetermined frequency operable to produce a first signal of said frequency, which is fed to an amplifier which amplifies the power level of the first signal to produce a first higher power signal. A switch/controller circuit both switches on and off the feed of the first signal from the oscillator to the amplifier and controls the amplifier. The first higher power signal is fed to an output. The oscillator may produce a first signal and an inverted first signal, with the amplifier amplifying the first signal and the inverted first signal, and with both the first higher power signal and the inverted first higher power signal being fed to the output.

Abstract: A differential-type voltage-controlled oscillator (VCO) with low-frequency stability compensation is disclosed. The differential-type VCO comprises a voltage-to-current converter for converting an input voltage signal into a biasing current signal to control the frequency of the VCO output. The VCO further comprises a number of stages of differential amplifiers connected in cascade. Each of the stages of differential amplifiers includes a pair of differential input PMOS transistors, with each of the PMOS transistors connected to a pair of NMOS load transistors. Each of the pair of NMOS load transistors are connected in parallel. The VCO further comprises a number of stages of bias circuits connected in cascade. Each of the bias circuits is connected to a corresponding stage of the differential amplifiers for receiving the bias current generated by the voltage-to-current converter.

Abstract: A oscillator having two synchronized oscillator rings is described. Synchronization is accomplished by circuitry connected between the outputs of two aligned stages in coupled oscillator rings, the circuitry being operable to maintain outputs of the stages 180.degree. apart in phase.

Abstract: A monolithic CMOS phase-lock loop (PLL) circuit provides a high frequency of operation suitable for RF applications. The PLL produces an output clock with high spectral purity and very low jitter. The output clock has a low static phase error relative to a reference input, making the PLL also useful for clock synchronizing applications, such as clock recovery elements in transmission/recycling channels. The PLL provides in-phase and quadrature signals from a VCO which has two differential transconductor stages having negative output conductance.