Abstract: A CR-type oscillator circuit of the invention includes a reference resistor; a current mirror circuit for taking out the current flowing in the reference resistor; and a reference capacitor whose charging and discharging is repeated by the current taken out by the current mirror circuit within a predetermined potential changing range which is determined by a resistor divider network formed by a plurality of resistors connected in series. The oscillator circuit further includes a control circuit for maintaining at a constant value the ratio between the potential changing range of the charging and discharging of the reference capacitor and the potential difference developed across the reference resistor. The CR-type oscillator circuit of the invention generates stable oscillation frequency which has no dependency on the power supply voltages or the threshold voltages of the transistors concerned.

Abstract: An oscillator for generating a master clock frequency and also dividing that frequency by two. The oscillator uses one flip-flop of a dual D package as the generator for the master clock frequency and the other flip-flop in that package to divide that frequency by two.

Abstract: A high-frequency wideband relaxation oscillator utilizing parasitic capacitances of the switching transistors as charging capacitors and capable of being fabricated in both CMOS and NMOS technology. When fabricated in NMOS technology the switching transistors are implemented as charge-enhancement devices and additional charge-depletion devices are utilized to counteract detrimental parasitic capacitances.

Abstract: A delay-controlled relaxation oscillator includes a capacitance in the oscillator which is alternately charged and discharged. The change-over from charging to discharging is controlled by means of a comparator which compares the capacitance voltage with a reference voltage. The oscillator also includes switching means for reducing the power consumed by switching the power supply for the comparator from the power supply mode into a stand-by mode between two change-overs.

Abstract: In the voltage controlled oscillator disclosed herein, the charging and discharging of a timing capacitor is controlled by a differential input comparator which establishes precisely defined switching thresholds. The comparator input circuit is provided with an internally generated, temperature compensated input bias current which substantially relieves the timing components from providing bias current, thereby facilitating a wide range of operation.

Abstract: A voltage controlled oscillator (VCO) comprises the series arrangement of two signal inverters whose outputs are coupled to the input of the first signal inverter through a feedback loop, and a control circuit including a series arrangement of two diodes arranged in the same direction, whose interconnected electrodes are coupled to the input of the first inverter. The other electrodes of the diodes form inputs for two control voltages with which the frequency of the VCO can be varied over a continuous range. The VCO is used in a phase locked loop which includes a phase detector for generating an error signal representative of a phase difference between a reference signal and a signal taken from the VCO, and a loop filter for producing a control signal from the error signal. The phase detector is arranged as an EXOR gate with a first input for the reference signal voltage and a second input for the output voltage of the VCO.

Abstract: This high-precision oscillator stage, with reduced response times, includes only NPN transistors on the signal path and comprises a threshold detector circuit connected to a first and to a second threshold voltage and to the output of the stage so as to generate a differential voltage output signal which switches when each voltage threshold is reached, a control and memory circuit comprising a differential voltage detector connected to the output of the threshold detector and generating a charge and discharge signal depending on the state of the circuit, a memory element controlled by the differential voltage detector to maintain the charge and discharge states and an output driving circuit connected to the control and memory circuit so as to supply an external capacitor with constant currents so as to alternately and periodically charge and discharge the capacitor.

Abstract: A CMOS relaxation oscillator is disclosed employing a pair of capacitors and individual charging means. A noninverting amplifier comprising two cascaded inverters is provided with a transmission gate input circuit that alternately switches the amplifier input between the two capacitors. A pair of switches coupled respectively across the capacitors alternately discharge them. The resulting oscillator has a frequency determined by the capacitor charging periods. Accordingly, the frequency and duty cycle can be predetermined as desired. The circuit can also be made either power supply tunable or power supply independent.

Abstract: A relaxation oscillator in which a capacitor is periodically charged and discharged. The relaxtion oscillator includes two transistors connected parallel to the capacitor with their base-emitter paths in anti-parallel. When a voltage equal to the base-emitter voltage of one of the transistors is reached, this transistor is turned on so that:(a) the capacitor is not charged further, and(b) switching over takes place from charging to discharging (i.e. charging in the opposite sense). Thus, the effect of noise on the instant of switching over is substantially reduced.

Abstract: A multi-function circuit including an oscillator, a pulse generator and an integrator which share a common timing capacitor. The pulse generator is run by double ended charging of the timing capacitor. The integrator shares the threshold setting circuitry of the oscillator and in turn the pulse generator shares and makes use of the threshold setting circuitry of both the integrator and the oscillator. During operation of the pulse generator, positive feedback through the capacitor aids in providing a rapid and complete discharging of the timing capacitor 16 below the lower threshold of the oscillator. A selector input selects between the oscillator and pulse generator and the integrator provides a predetermined time delay in which the selection is verified.

Abstract: A transient waveform generator capable of generating waveforms having operator specifiable characteristics, including amplitude, rise time, and phase inversion.

Abstract: An oscillator with noise rejection and a fifty percent duty cycle for the on-chip generation and conversion of a sine wave to a square wave, using an external reference crystal. The circuit comprises a low gain current switch including a first and second switching transistors, with the control lines of the switching transistors connected to a reference voltage line. The reference crystal is connected across the control input and the current receiving terminals of the first transistor so that a square wave is obtained at the current receiving terminal of the second transistor. A threshold circuit is included for adjusting the voltage of the square wave signal from the second transistor and applying the adjusted signal to a diode-coupled receiver circuit, which provides the output for the circuit.

Abstract: An integrated NMOS circuit includes an external connection terminal to be connected to an external component, a control voltage terminal, a supply voltage terminal, a reference voltage terminal, a circuit output terminal, a voltage controlled transistor network having an input connected to the control voltage terminal and an output connected to the external connection terminal, a control device supplied by a voltage source through the supply voltage terminal and the reference voltage terminal, the control device having an input connected to the voltage controlled transistor network and an output fed back to the transistor network and connected to the circuit output terminal, the transistor network including a switchable charging current source and a switchable controlled discharging current source, the switchable controlled discharging current source being controlled by a control voltage connected to the control voltage terminal, the switchable charging current source and the switchable controlled discharging

Abstract: An integrated circuit oscillator which includes a capacitor, a reference current source coupled to the capacitor used to charge the latter, and a trigger circuit coupled to the capacitor having an upper input threshold for changing from a first state to a second state and a lower input threshold for changing from the second to the first state. A discharge circuit is coupled to the trigger circuit and is operative to discharge the capacitor in response to the trigger circuit changing states and to cease the discharging on changing back to its original state.

Abstract: A voltage controlled oscillator includes an inverting amplifier connected to a resonant feedback network and a comparator for comparing the input to the inverting amplifier to a reference voltage which is equal to the threshold voltage of the inverting amplifier. As a result, the oscillator provides a square wave output having a precise one-to-one duty cycle. In addition, circuitry is included for causing the oscillator to start up at a steady state value and predetermined phase.

Abstract: An oscillator circuit is disclosed in which a charging path is provided through a charging transistor and a discharging path is provided through a discharging transistor. Both the charging path and discharging path are directed through a first and second terminal for connection across a timing resistor to allow for reliable 50% duty cycle operation. A diode is provided between a voltage limit setting circuit and a second diode. The second diode is connected to the base of a buffer transistor. The buffer transistor turns the discharging transistor on and off. The two diodes provide a delay between the time in which the voltage limit setting circuitry changes the voltage limit and the switching of the discharging transistor to prevent latch-up.

Abstract: This high accuracy, RC oscillator, particularly for monitors, has different switch-over thresholds independent from such variable parameters as the saturating voltage of transistors, and has a high operating frequency. The oscillator comprises a capacitor having an output terminal, a capacitor power current source, and a control section. The control section is composed of a plurality of differential stages sharing a common input and each having an input connected to a different switch-over threshold. The control section further comprises a switch-over drive stage connected to the oscillator output terminal and to an input terminal thereof for controlling activation and deactivation of the different differential stages (and hence, of the respective associated thresholds) according to the signal present at the output and input terminals of the oscillator.

Abstract: Changes in the output frequency of a voltage controlled oscillator circuit due to temperature changes are compensated for by shunting a resistor with two series diode resistor combinations. The variation in the diodes' voltage drip with temperature provides a resistance that varies with temperature, to correct for other resistance or capacitive changes with temperature in the circuit, thereby obtaining a more stable oscillator frequency in a varying temperature environment. Compensating for temperature effects by shunting a resistor with a means whose resistance decreases with temperature is a method applicable to circuits other that oscillators.

Abstract: In a comparator circuit in which the active element is a long-tailed transistor pair the input bias current to at least one input of the pair is maintained constant by providing a supplemental current from a current source. A multivibrator incorporating the comparator is also described.

Abstract: An oscillator for an integrated circuit which includes a Schmitt trigger having an upper threshold voltage V.sub.H and a lower threshold voltage V.sub.L, a capacitor coupled between an input to the trigger and ground, a current generator coupled to the trigger input for charging the capacitor at a constant rate and a current generator coupled to the trigger input for discharging the capacitor at a constant rate. A charge switch in series with the charging current generator reversibly couples the charging current generator between a source of high voltage and the trigger input in response to a change in state of the trigger from a first state to a second state. A discharge switch in series with the discharging current generator reversibly couples the latter across the capacitor in response to a change in state of the trigger from the second state to the first state.

Abstract: An IC oscillator is disclosed using a small capacitor to determine the fundamental frequency. The capacitor is small enough to permit an on chip capacitor to be used. The capacitor is charged and discharged at the same rate between voltage limits established in the circuit. A single voltage controlled current source controls the charge and discharge currents equally so as to provide a relative low voltage-controlled frequency. The circuit can operate at very low charging currents so that a wide range of control is available. The circuit is configured to produce a very low radiation level.

Abstract: A simple oscillator circuit is capable of generating a plurality of frequencies that are completely independent of one another, any one of which frequencies can be freely selected. The oscillator may be used as part of an electronic ringer for a telephone, for example. The oscillator circuit includes a capacitor which is charged from a current source. A discharge constant current circuit discharges the charge from the capacitor. A comparator compares the charge voltage on the capacitor with a first or a second reference voltage. In response to the output of the comparator, a reference voltage switching control circuit supplies the first or second reference voltage to the comparator and controls the turning on and off of the discharge constant current circuit. A control constant current source controls the current from the charge current source for charging the capacitor.

Abstract: A voltage controlled oscillator circuit is provided wherein the frequency of the output is increased or decreased by a .+-.DC control voltage centered at 0 VDC. The output of the oscillator has a constant on/off ratio and the ratio holds constant over the frequency control range.

Abstract: A continuously tunable function generator comprises a first function generator (10) with a triangle voltage generator including a comparator (24), which controls the commutation of a capacitor (14) from a charging phase to a discharging phase and vice versa in relation to an upper and lower preset amplitude value of the voltage at the capacitor (14). The triangle voltage (50) arising at the capacitor (14) is supplied to a second comparator (32) of another triangle voltage generator. The second comparator (32), commutates a second capacitor (38) of the same capacitance as the first capacitor from the charging phase to the discharging phase and vice versa. A reference voltage corresponding to the mean value of the upper and the lower amplitude value is applied to a second input of the second comparator. The charging currents and the discharging currents are identical, constant, and adjustable for changing the frequency of the triangle voltages.

Abstract: In a monolithic integrated RC-oscillator comprising only one external frequency-determining network of a capacitance and a discharge circuit, a charging circuit which can be switched on and off periodically is connected to the network, which charging circuit is switched on and switched off by means of a threshold circuit with two switching thresholds when the voltage across the capacitor of the network reaches the lower and the upper switching threshold, respectively. In order to ensure that the frequency of the generated sawtooth signal is independent of a fixed discharge current, which is subject to spreading, and of the temperature coefficient of this current, the charging current of the charging circuit is controlled by the voltage across a second capacitor, which is charged or discharged with a current (I.sub.1) when the frequency-determining capacitance is discharged and which is discharged or charged with a second current when said frequency-determining capacitor is charged.

Abstract: An oscillator including a non-inverting amplifier coupled in series with an inverting amplifier. A first feedback network couples the output from the non-inverting amplifier to the input of that amplifier by way of a capacitor C. A second feedback network couples the output of the inverting amplifier to the input of the non-inverting amplifier by way of a series connected resistor R, and includes a capacitor coupled between the input of that non-inverting amplifier and a reference potential. A third feedback network generates a feedback signal proportional to the difference between the average voltage at the output of the non-inverting amplifier and the average voltage at the output terminal of the inverting amplifier, and couples that feedback signal to the input of the inverting amplifier.

Abstract: A voltage controlled oscillator circuit is disclosed. A CMOS circuit version is detailed. A relaxation oscillator has its input coupled by way of a voltage follower buffer to the input terminal where the control voltage is applied. The operating frequency is determined by the circuit resistor and capacitor values along with the control potential. A linear frequency versus voltage response is obtained and the circuit will operate at low supply voltages.

Abstract: The fall-time of an ECL gate is precisely controlled using a fixed capacitor, which is connected between the positive supply voltage and the ECL gate output terminal, and a variable current source connected between ground and the ECL gate output terminal. A time-delay circuit is obtained by controlling the variable current source with an error voltage of a phase-locked loop such that the time-delay precisely tracks the frequency of the reference signal for the phase-locked loop. A signal detector circuit is obtained by combining time-delay circuits. A voltage-controlled oscillator is assembled by connecting 3 ECL gates with controlled fall-times in a ring oscillator configuration. Addition of a non-inverting input to one ECL gate makes the voltage-controlled oscillator interruptible. Combining a voltage-controlled oscillator of the type described with a phase detector fed by a reference signal provides a phase-locked loop with the control voltage thereof providing a frequency-to-voltage conversion function.

Abstract: An alternating current small-signal detector is disclosed in which an oscillator output frequency jumps from a first frequency of oscillation to a second frequency of oscillation in response to the alternating current signal exceeding a predetermined value. The predetermined value is maintained over changes in input offset voltages by a feedback network which changes only the oscillator duty cycle.

Abstract: A hysteresis circuit producing a relatively stable hysteresis output signal, which includes a power source, a reference potential source, a transistor, a constant current source, output means and means for detecting the collector current and for controlling the constant current source. The transistor is connected at its collector to the power source via the constant current source and at its emitter to the reference potential source. The constant current source supplies a constant current switchable between first and second levels. The output means is responsive to the first and second levels of current for deriving a bilevel hysteresis output signal dependent on the first and second levels of current. The detecting and controlling means detects the collector current of the transistor and controls the current source between the first and second levels of current in response to the collector current.

Abstract: A current to frequency converter comprising a current source, for example a photocell, a voltage to frequency converter, an integrator in the feedback loop of the converter, the current source being connected to the summing junction of the converter and integrator such that the frequency of output pulses from the converter is directly proportional to the magnitude of current injected from the converter to the summing junction, and a controlled circuit for attenuating the current injected from the converter to the summing junction to increase the frequency of output pulses. The controlled attenuating circuit includes a transistor switching arrangement for introducing increased resistance in the path for current injected from the converter to the summing junction in response to the presence of a control signal.

Abstract: A sine wave generator circuit for providing, as its output, a substantially perfect sine wave signal includes a multiplier responsive to first input and second input signals of varying magnitude for providing as its output the sine wave signal as a function of the two input signals. There is further included a first feedback circuit path connected between the output and one of the inputs of the multiplier which includes a resistance-capacitance network for providing a phase delayed representation of the output signal as the first of the input signals. The amount of phase delay is determined by the relative values of the resistance-capacitance network and determines the frequency of the sine wave output. Further included is a reference signal the magnitude of which will determine the magnitude of the sine wave output signal. The reference signal is applied to a second feedback circuit path connected between the multiplier output and the other one of its inputs.

Abstract: An oscillation circuit having a reference voltage circuit for forming a reference voltage by dividing a power supply voltage. The reference voltage circuit supplies the reference voltage to one of the input terminals of the comparing circuit. A charge/discharge voltage is supplied from a junction between a transmission gate circuit and a CR circuit to the other input terminal of the comparing circuit. The comparing circuit compares the charge/discharge voltage with the reference voltage to produce pulse signals.

Abstract: A triangle waveform generator having a comparator which drives an integrator via a limiter is disclosed. At the output of the integrator, the desired triangular waveform voltage is present. The output of the integrator is connected to a first input of the comparator. The output of the comparator is fed back to its first input via a resistor. The output of the integrator is coupled via an integral action controller to a second input of the comparator. The integral action controller has a substantially longer time constant than the integrator. With this circuit, a triangular voltage is obtained, the parameters of which, namely, the slope and the positive and negative peak values, depend only on resistors and reference voltages which can be set within narrow tolerances.

Abstract: An adjustable frequency oscillator 2 is provided by a comparator timer 4 having a potentiometer 6 at its output 8 for concurrently changing both charging current and threshold trip voltage to control the frequency of oscillation of the comparator output. The oscillator is ideal for proximity switch applications, particularly photoelectric type proximity switches, for timing a delayed output signal following a given sensed condition.

Abstract: A modulator transmitting an analog data signal by variation of the frequency of an oscillator comprising an integrator (1, 2) and a bistable circuit with trigger hysteresis (8 to 13). The two-level voltage from the bistable circuit, taken to a terminal of a resistor network (6, 7, 30) connected to the input of the integrator, is formed from the potential O and the potential kU, which is lower than the supply voltage U, applied respectively to the inputs of two analog switches (12, 13) whose outputs are connected to the output of the bistable circuit. The data signal v.sub.e is applied to the input of a conversion circuit (17) arranged to supply voltages v.sub.e1 and v.sub.e2 varying linearly as a function of v.sub.e and symmetrically with respect to kU/2 and applied respectively to the inputs of two further analog switches (26, 27) whose outputs are connected to another terminal in the resistor network. The input and output signals of the inverter (9) of the bistable circuit are used to control the switches.

Abstract: The sawtooth voltage generator is intended in particular for use as a clock and reference voltage generator of an electronic regulating means for a motor vehicle heating system. The generator has an output voltage having a leading edge determined by a first RC circuit and a trailing edge determined by a further RC circuit. A first capacitor (C1) and a second capacitor (C3) are charged rapidly; the second capacitor (C3) has its own discharging circuit, e.g. a resistor (R7). The curve form of the trailing edge of the output voltage can be substantially freely determined with a nonlinear wave shape which is suitable for compensating for non-linear characteristics of elements of a regulating apparatus intended for receiving the output voltage with the operating frequency being determined by the discharge circuit (R4), the first capacitor (C1).

Abstract: A switched capacitor oscillator is constructed by providing a damped resonator network with a comparator as a nonlinear feedback element by connecting the input of the comparator to the output of a first operational amplifier of the resonator network and connecting the output of the comparator to the input of the resonator network. The comparator thus becomes a saturable positive feedback element for the resonator network. Also disclosed is a startup network for the oscillator and an input network which derives an input from a reference voltage in order to eliminate supply voltage noise and provide precision control of amplitude.

Abstract: An oscillator unit having a charge storage device periodically rapidly charged through a small resistor and slowly discharged through a large resistor under control of a comparator for producing an oscillatory output and a switch actuatable by means of a frequency controlled zero-crossing multiplier to selectively discharge the storage device and thereby repeatedly resynchronize the oscillator unit with the frequency input to the multiplier.

Abstract: An oscillator including an amplifier which is formed by CMOS inverters and has a positive feedback path from an output to an input of the amplifier. The positive feedback path includes a capacitor which is alternately charged and discharged by switched constant current devices controlled by the amplifier and connected to the amplifier input. The amplifier includes a second capacitor in a negative feedback path to limit voltage swings at the amplifier input. The constant charging and discharging currents can be produced by current mirrors which are controlled to control the oscillation frequency.

Abstract: A low frequency pulse generator apparatus utilizing an R-C timing network which includes a plurality of selectable capacitors to provide frequency pulse rates over a predetermined range. A counter which may be set to count a finite number of pulses, controls the generated pulse total.

Abstract: An oscillator circuit adapted for use as a voltage controlled oscillator in which all of the transistors of the oscillator circuit are operated in non-saturated regions so that the minority carrier accumulation time does not affect the maximum operating frequency of the circuit. First and second current mirror circuits are coupled to opposed outputs of a differential amplifier circuit and are coupled to charge and discharge a capacitor with constant current in response to the states of the differential amplifier circuit. The differential amplifier circuit is provided with a hysteresis characteristic.

Abstract: A CR oscillation circuit is provided which includes inverters which are connected in series and whose operating current paths between a power source terminal and a ground terminal are connected in series with a constant current source. In certain embodiments, a resistor is connected between the output terminal of one inverter and the input terminal of the first inverter, and a capacitor is connected between the output terminal of another inverter and the input terminal of the first inverter. The CR oscillation circuit further has a constant current source connected in series with the operating current path of said inverters between the power source terminal and the ground terminal. In other embodiments, the resistor and capacitor are connected in parallel and to the input of an inverter.

Abstract: A frequency encoding closed loop circuit with transducer, comprising a closed inner digital loop nested in a closed outer loop which carries both digital and analog signals, associates a corresponding frequency output to variations in the magnitude of physical quantity input to a transducer which is contained within the outer loop. The encoder achieves the advantage of synchronous detection in converting changes in a transduced quantity into a frequency count. The encoder produces frequency shifts at its output that are proportional to the transducer input and are significantly immune to noise and power input fluctuations.

Abstract: An analog voltage to duty cycle converter is provided using a series connected resistor and capacitor. The capacitor is charged in one direction through the resistor from the difference between the analog voltage and a reference voltage maintained across a zener diode by one polarity of output from a differential amplifier responding to the charge across the capacitor. When the charge across the capacitor reaches the difference necessary to cause the differential amplifier to change the polarity of its output, a positive feedback firmly toggles the output to the other polarity and the capacitor is allowed to charge in the opposite direction due to cut-off of the zener current by a diode in the amplifier output circuit. The capacitor then charges in an opposite direction due to the analog voltage alone and the reference voltage again switches "on" when the amplifier output goes positive. The duty cycle is then proportional to the analog voltage.

Abstract: An oscillator circuit having a variable duty cycle for controlling the power level of a microwave oven provides an adjustable RC time constant circuit including a capacitance branch and a resistance branch and coupling means therebetween, the resistance branch including a pair of alternately selectable current paths for the charging and discharging of the capacitance branch, the coupling means including semiconductor switch means for selecting and coupling either of the current paths to the capacitance branch for changing the charging and discharging of the capacitance branch in accordance with the selected current path, and one of the current paths including a pair of parallel connected portions with each of the parallel portions having a diode connected therein for controlling the direction of current flow, the diodes being connected with opposite respective polarities for allowing current flow only in opposite directions in the respective portions, the one current path further including a potentiometer hav

Abstract: A Schmitt trigger astable multivibrator circuit includes a first inverter, a second inverter whose input terminal is connected to the output terminal of the first inverter, a third inverter which is constituted by a first P-channel transistor and a first N-channel transistor serially connected and whose input and output terminals are respectively connected to the output and input terminals of the second inverter. The Schmitt trigger astable multivibrator circuit further includes a second P-channel transistor connected between a positive power supply terminal and the first P-channel transistor, and a second N-channel transistor connected between a ground terminal and the first N-channel transistor, and an input signal supplied to the first inverter is also applied to the gates of the second P-channel and N-channel transistors. The astable multivibrator also includes a time constant circuit, activated in response to the second inverter's output, which connects to the first inverter's input.

Abstract: A circuit for controlling the frequency of a pulse generator associated with a microprocessor that is connected to power line frequency, uses an RC-stage which is connected ahead of the pulse generator as the frequency-determining element and which has a resistor 19 that is variable by a control signal derived from the microprocessor. The control signal is obtained by comparing the power line frequency and the pulse frequency with one another.

Abstract: In an oscillatory signal generator circuit exceptional frequency stability is insured by the use of interrelated constant current sources (520, 521, 522) that provide an insensitivity to supply voltage variations over a wide range. Two of the current sources determine the duty cycle by controlling the charge and discharge current of a capacitor (C) in the circuit. A third current source determines the voltage swing on the capacitor. By varying the current output from the third current source, the generator circuit provides a variable frequency signal.

Abstract: Power consumption is substantially reduced and constant frequency is substantially derived without regulating the supply voltage for an oscillator circuit of the type wherein a capacitor is recurrently charged to a threshold voltage from the supply voltage and is then discharged through a gate turn-off (GTO) device. A reference voltage level proportional to the supply voltage is applied at the control electrode of the GTO device and positive current is applied at that control electrode when the differential between the charge voltage level and the reference voltage level reaches a positive trigger level, while negative current is applied thereat when that differential reaches a negative trigger level.