Showing papers on "RC circuit published in 1989"

Surgery operating device

Abstract: PURPOSE: To effectively cut and machine a hard tissue by forming an ultrasonic vibrator to be a bolt fastening Langevine type vibrator and composing the feedback circuit of a vibration feedback type oscillator of a vibrating voltage detecting circuit, phase comparator, low-pass filter, error amplifier and voltage control oscillator. CONSTITUTION: A vibration feedback type oscillator 1 rectifies the current of an alternative current power supply by a rectifier circuit 2 and makes the direct current power source for driving circuit elements in the oscillator 1 and for driving the bolt fastening Langevine type vibrator of hand pieces 12 and 13. The current flows from the rectifier circuit 2 to an overload control circuit 3 and an amplitude adjusting circuit 4. By varying the output voltage of the amplitude adjusting circuit 4, the amplitude of ultrasonic vibration generated in the hand pieces 12 and 13 can be adjusted. For oscillation, a reference frequency, outputted from a feedback circuit 11 is inputted to an amplifier circuit 5, amplified, passe through a filter 6 and a transformer 7 and is inputted to an amplifier circuit 8. The signal current of a resonance frequency from the transformer 7 is amplified by the amplifier circuit 8, boosted in voltage by a transformer 9, passes through a matching circuit 10 and is inputted to the feedback circuit 11. COPYRIGHT: (C)1990,JPO&Japio

A new floating resistor for CMOS technology

Abstract: A new floating resistor consisting entirely of MOS devices in saturation has been developed. Linearity within +or-0.04% is achieved through nonlinearity cancellation via current mirrors over an applied voltage range of +or-1 V. The frequency response exceeds 10 MHz, and the resistors are expected to be useful in implementing integrated circuit active RC filters. >

Feedback-coupled high-frequency power oscillator

Abstract: A high-frequency power oscillator is built around a power amplifier utilizing semiconductors in a complementary or quasi-complementary stage which operate in a switching mode of operation. The output of the amplifier supplies high-frequency oscillations to a load impedance through an output filter composed of a series-resonant circuit and a parallel-resonant circuit. A feedback driving voltage is obtained from the output filter in a manner providing a first portion of the driving voltage from a voltage present in the parallel-resonant circuit for voltage feedback and a second portion of the driving voltage obtained by current inverse feedback from the current in the series-resonant circuit. These two components of the driving voltage are combined in an addition circuit and supplied to an input of the power amplifier through a pulse modification stage. In the case of high load impedances the operating frequency is as close as possible to the resonant frequency of the parallel resonant circuit and the superimposed current inverse feedback prevents the provision of an operating frequency that would approach the resonant frequency of the series-resonant circuit even when the losses in the series-resonant circuit are small. The ability to use a low-loss series-resonant circuit makes possible increased operation reliability, safety and efficiency.

Switching circuit providing adjustable capacitive series voltage dropping circuit with a fractional horsepower motor

Abstract: A control circuit for a fractional horsepower fan motor connected between hot and neutral wires in and AC circuit is shown. The control circuit includes two or more duplicate branches. Each branch is serially connected, and each branch includes a triac, series resistor and series capacitor. The triac has a gate terminal which is connected to an optical coupling circuit for isolation and responds to a control signal from a low voltage small current source. In an alternative embodiment, a single triac and optical coupling circuit can be used with different capacitors being switched in or out of the circuit.

Sspice-a symbolic SPICE program for linear active circuits

Abstract: Sspice, a symbolic SPICE circuit simulator, is described. Input files are in the SPICE format, and the program performs a symbolic AC analysis. In addition menu options are available for evaluating second-order active RC circuits. These include identifying and solving ideal filter formulas and approximating pole shift due to finite op-amp gain-bandwidth product. >

Bounds on signal delay in RC mesh networks

Abstract: The linear RC delay model is commonly used in timing simulators for MOS digital circuits. Most simulators only handle tree networks, not arbitrary networks. More precisely, these simulators treat all networks as if they were trees. Currently, the only alternative is to invert the node-conductance matrix of the RC network numerically. Upper and lower bounds on signal delays in general RC networks are derived. The idea is to bound (element-wise) the inverse of the node-conductance matrix of the network, and use these bounding matrices in formulas for estimating signal delays in RC networks. Evaluating the bounds requires finding the least-resistance paths and the maximum cut between the input mode and the rest of the nodes in the network. For tree networks, the bounds coincide and are the same as those found by using a method due to P. Penfield, et al. (1970). >

Calibrated physical parameter value measurement system

Abstract: A circuit for measuring a parameter value by measuring the time required to charge a capacitor in a sensor RC circuit from a first to a second voltage includes a reference RC circuit whose capacitor is also charged between two voltage levels. The circuit is calibrated so that the time interval required to charge the reference capacitor may be used to improve the accuracy with which the parameter value is measured.

Peak voltage holding circuit

Abstract: In a peak voltage holding circuit, a leakage circuit includes a first-stage mirror circuit, a second-stage mirror circuit, a selecting circuit, a capacitor, and a control circuit. The first-stage mirror circuit has one end connected to a second potential. The second-stage mirror circuit has one end connected to the output side of an input circuit and the other end connected to a first potential, and causes a current corresponding to a current which flows through the first-stage mirror circuit connected to the first potential to flow out from the voltage holding capacitor. The selecting circuit is connected the other end of the first-stage mirror circuit. The capacitor has one end connected to the selecting circuit and the other end connected to the first potential. The control circuit is connected to the selecting circuit and controls an operation of the selecting circuit. The selecting circuit alternately connects one end of the capacitor to the other end of the first-stage mirror circuit and the first potential at every arbitrary period.

Calculation of signal delay in integrated interconnections

Abstract: A procedure for calculating the signal delay in integrated interconnections modeled by RC networks is presented. This method is based on the elimination of all the internal nodes of the RC network, using a first-order approximation. The method is valid for calculating the approximate transient response of RC mesh networks, not only for a step input, but also for inputs of many different waveforms. >

Release circuit monitoring circuitry for motor vehicle safety system - has test circuit connected to control terminal via limiting capacitor for duration of current flow

Abstract: An ignition switch with a control terminal switches, on an electrical ignition element of the safety system, esp. a passenger or drive retaining system such as an air bag, belt tightener or similar. A test circuit (8)is connected, via a limiting capacitor (c2) for duration of current flow, to a control terminal, i.e. input (11), base of a transistor (T). The test current (Ipruf) flowing from a detecting circuit (C1,8) via the ignition element (5) in the form of an ignition fill (2P) is evalucated. The limiting capacitor is part of an RC circuit (21), the resistance element (R1) providing a potential. A decoupling diode (D3) is in parallel with the capacitor (C2). The control terminal (11,T) is connected to a release sensor (17). USE - Tests release circuit to ensure that no faultly release functioning occurs.

Current-voltage converting circuit utilizing CMOS-type transistor

Abstract: A current-voltage converting circuit applicable to a linear integrated circuit of CMOS-type having a wide-ranged operational voltage, comprising a buffer circuit for buffering and amplifying a current being input to an input terminal; a gain circuit for outputting a voltage in proportion to the output voltage of the buffer circuit; and a current reference circuit constituted in a current mirror by P-channel transistors; N-channel transistors and a reference voltage and is adapted to supply a constant voltage to gates of P-channel transistors provided in the gain circuit.

Analog/digital converter circuit

Abstract: An analog/digital converter circuit including a capacitor having a first end, to which an analog voltage is applied, and a second end, an input buffer circuit having an input terminal, connected to the second end of said capacitor, and an output terminal, a reference voltage generating circuit for generating a plurality of reference voltages having different voltage levels, a voltage comparator circuit having a plurality of voltage comparators for comparing the output voltage of the input buffer circuit with each of the reference voltages generated by the reference voltage generating circuit, and generating a digital signal corresponding to the comparison results, a decoder circuit for decoding the output of the voltage comparator circuit, and D.C. bias voltage selection/supply circuit for selecting one of the reference voltages of the reference voltage generating circuit and supplying the selected reference voltage as a D.C. bias voltage to the input terminal of the input buffer circuit.

Semiconductor MIS integrated circuit device

Abstract: In an oscillation circuit consisting of an amplification circuit portion composed of transistors of input/output circuit basic cells of a gate array disposed on a semiconductor pellet and an oscillator disposed outside the semiconductor pellet, the amplification circuit portion consists of transistors for an output circuit of the input/output buffer circuit basic cells. The dielectric breakdown characteristics of the amplification circuit portion of the oscillation circuit can be improved because the structure of the transistor for the output circuit is more highly resistant to dielectric breakdown than the structure of the transistor for the input circuit.

Modeling of the distributed gate RC effect in MOSFET's

Abstract: Scattering parameters of wide MOSFET devices have been measured at the wafer level in the frequency range up to 1 GHz. These scattering parameters are converted to Y-parameters for device characterization and compared with SPICE simulations of L-, Pi -, and T-ladder distributed RC circuits taking into account the effect of distributed gates. Good experimental agreement shows that this effect can be modeled appropriately by multisection RC ladders, especially T-ladder circuits. Differences among ladder circuits in modeling this effect are discussed qualitatively. >

Non-volatile programmable interconnection circuit

Abstract: A programmable interconnection circuit includes first and second ferroelectric capacitors which differentially store the programming state of the circuit. A principal application of the circuit is in the programming of cells within a gate array integrated circuit. The programmable circuit is non-volatile due to the storage of polarization state within the ferroelectric capacitors. Differential voltage states are applied to programming nodes which set the state of a cross-coupled amplifier that, in turn, drives p-channel and n-channel transistors which are connected between first and second nodes of the integrated circuit. A drive line signal applied to terminals of the ferroelectric capacitors goes between high and low voltage states to set differential polarization states into the capacitors. Following restoration of power to the integrated circuit, which includes the programmable circuit, a pulse is applied through the drive line to the ferroelectric capacitors to create differing voltages at the program nodes. These different voltages are differentially amplified to produce the required voltage states to reestablish the programmed interconnection for the circuit.

Analog continuous-time MOS vector multiplier circuit and a programmable MOS realization for feedback neural networks

Abstract: A neuron circuit and a neural network including a four quadrant analog multiplier/summer circuit constructed in field effect transistors. The neuron circuit includes the analog multiplier/summer formed of an operational amplifier, plural sets of four field effect transistors, an RC circuit and a double inverter. The multiplier/summer circuit includes a set of four identical field effect transistors for each product implemented. This produces a four quadrant multiplication if the four field effect transistors operate in the triode mode. The output of the multiplier/summer is the sum of these products. The neural network includes a plurality of these neuron circuits. Each neuron circuit receives an input and a set of synaptic weight inputs. The output of each neuron circuit is supplied to the corresponding feedback input of each neuron circuit. The multiplier/summer of each neuron circuit produces the sum of the product of each neuron circuit output and its corresponding synaptic weight. The individual neuron circuits and the neural network can be constructed in MOS VLSI.

Three state emitter coupled logic circuit with a small amount of current consumption

Abstract: A three state emitter coupled logic circuit has a logic circuit responsive to an input logic signal and a three state control signal, a difference circuit formed by two series combination of resistors and bipolar transistors coupled in parallel as well as a constant current source coupled between the difference circuit and a constant source, and an emitter follower circuit coupled to an intermediate node between one of the resistors and one of the bipolar transistors for producing an output signal, and a bypassing circuit is provided in parallel to the constant current source for increasing the amount of current passing through the difference circuit in the presence of the three state control signal of the active level, so that the voltage level at the intermediate node is varied out of the usual voltage range for the logic function mode, thereby the three state emitter coupled logic circuit being established in the high impedance state.

Voltage controlled oscillator (VCO) circuit with enhanced frequency selection range

Abstract: A voltage controlled oscillator (VCO) circuit includes a current mirror circuit section and oscillator circuit section to provide an oscillation frequency based on the output current of the current mirror circuit section. To vary the oscillation over a wide range, a fixed reference voltage circuit is connected to the current mirror circuit, and either a source follower circuit made of a MOSFET or a FET or an emitter follower circuit made of a bipolar transistor is included is also connected to the current mirror circuit to selectively varying the output current of the current mirror circuit section upon application of a control voltage applied to the follower circuit. Thus, the follower circuit is controlled by a control voltage while the output current of the current mirror circuit varies depending on the magnitude of the control voltage, and, in turn, the oscillating frequency of the oscillator circuit section varies over a wide frequency range, e.g., in excess of 100 dB, in accordance with the output current.

Integrated circuit RC filters with very large time constants

Abstract: This circuit is an input noise filter. An RC circuit comprises a capacitor implemented from a transistor with source and drain tied together and a long transistor acting as a resistance which can either be large or small, depending on the bias. The output of the RC circuit is applied to a comparator where it is compared to a threshold voltage. When a signal is first applied to the input, the resistance is high, so that the RC circuit charges slowly. With the input signal still applied, after the comparator threshold is reached and the output from the comparator goes high, a feedback circuit senses the output and decreases the resistance, allowing the RC circuit to rapidly charge up. Finally, after the input signal ends, the feedback loop again raises the resistance to allow the RC voltage to discharge slowly to the threshold level, after which the comparator output goes low. The result is a circuit that does not shrink the digital input signal but still filters out input noise.

Oscillation circuit for proximity switch

Abstract: An oscillation circuit of a proximity switch includes a parallel LC resonance circuit (L, C), an oscillation transistor (Tr6) controlled by an output voltage from the resonance circuit for switching a constant current and a feedback circuit (Tr2, Tr3) for feeding back a current flowing through the oscillation transistor to the resonance circuit. In the circuit, there is further disposed a feedback current increase circuit including a second transistor (Tr7) controlled by an output voltage from the resonance circuit and a resistor (R) connected in series to the second transistor. The resonance circuit is supplied via the feedback circuit with a feedback current obtained by adding a current flowing through the feedback current increase circuit and a current passing through the oscillation transistor, thereby developing a large change in the amplitude of the oscillation.

Integrated circuit high frequency input attenuator circuit

Abstract: An attenuator for use in an integrated circuit window comparator circuit provides voltage division across an input voltage divider including a large number of identical thin film resistor segments combined in various series and parallel arrangements so that resistive voltage division of the input signal is in the same ratio as capacitive voltage division of the input signal by parasitic capacitances of the resistors.

Low-pass distributed RC filter using an MOS transistor with near zero phase shift at high frequencies

Abstract: The signal transfer properties of an MOS transistor biased with zero drain-to-source voltage, under a four-terminal excitation, are examined. Analytical expressions for the admittance matrix are developed. These results are applied to the study of a distributed RC low-pass filter with phase shift recovery at high frequencies. Calculations for the filter gain and phase characteristics, including the transistor parasitics, are presented. This filter has been used successfully in the design of self-biasing high-gain gigahertz-band amplifiers. The analytical expressions can be easily incorporated in a circuit simulation program to accurately model distributed RC effects. >

Flow sensor incorporating a thermoresistor

Abstract: A thermal flow sensor constructed by a temperature control circuit which includes a bridge circuit consisting of a thermoresistor arranged in a fluid passageway and a plurality of resistors, and a correction circuit for correcting the output of the control circuit in accordance with a gradient of a flow rate detecting characteristic is described. The correction circuit includes a subtracting circuit for subtracting a predetermined value from an output of the control circuit, a voltage dividing circuit for dividing an output of the subtracting circuit and an arithmetic operating circuit for performing either an addition or a substraction between outputs of the dividing circuit and the control circuit. The correction circuit may further include an amplifying circuit for amplifying the output of the dividing circuit and may change the arithmetic operating circuit to the circuit for adding the outputs of the arithmetic operating circuit and the control circuit and for subtracting the output of the subtracting circuit from the added voltage.

DC-to-DC voltage-increasing power source

Abstract: A DC-to-DC voltage-increasing power source suitable for use in an audio device mounted on an automobile or a portable type audio device includes a DC power source, a drive pulse generation circuit for generating drive pulses which are in 180 degree phase relationship, a switching circuit of a push-pull connection supplied with operating voltage from the DC power source and driven between an on-state and an off-state in response to the drive pulses, a charge and discharge circuit including capacitors charged by being connected in parallel to the DC power source and discharging a sum voltage by being connected in series to the DC power source and an output takeout circuit for taking out this sum voltage as a voltage-increasing DC output. The switching circuit is constructed of voltage-controlled type elements whose on-state is changed in response to the level of an on-pulse in the drive pulses and the drive pulse generation circuit includes a pulse level changing circuit for changing the level of the on-pulse. in one aspect of the invention, the switching circuit includes a variable time constant circuit for transmitting an on-pulse with a relatively large time constant and an off-pulse with a relatively small time constant.

Multipole approximation of capacitively loaded VLSI interconnection

Abstract: A method for obtaining the multipole approximations of the transfer functions of capacitively loaded uniformly distributed RC lines is proposed. The use of this method for calculating the transients and transient-related parameters of capacitively loaded VLSI interconnections is discussed.

Miniaturized and integrated filters

Abstract: Miniaturized LC filters active RC filters mechanical filters switched-capacitor filters CCD filters crystal filters saw filters digital filters.

Input circuit of the all or nothing type, for an automatic control device

Abstract: An all or nothing input circuit 10 includes a current generator 24 connected in series with an impedance R1 intended to be connected in parallel with a sensor 12. In order to suppress variations in the supply voltage Va, the input circuit includes a supply circuit 32 whose output 34 is at a fixed predetermined potential 5V relative to the positive pole 18 of the supply voltage and constitutes a floating earth for the processing circuit 28, 30.

Programmable semiconductor memory circuit

Abstract: A programmable semiconductor memory circuit comprises a memory cell array (3), a write circuit (5) which is driven by a first power source voltage (Vw) only in a write mode for writing data into memory cells of the memory cell array, an address input circuit (15, 51, 52, 18) which is driven by a second power source voltage (Vcc) for supplying an address signal to the memory cell array, and an input level correcting circuit (16) supplied with the first power source voltage only in the write mode for supplying the first power source voltage to the address input circuit. The second power source voltage has a voltage higher in the write mode than in a read mode. The address input circuit has an arrangement such that an input threshold value thereof changes when the second power source voltage changes. The input level correcting circuit supplies the first power source voltage to the address input circuit to pull up a signal level at an input of the address input circuit in the write mode so that a signal having a high logic level at the input of the address input circuit is greater than that the input threshold value of the address input circuit.

Method and circuit for testing integrated circuit modules

Abstract: A method and circuit for identifying hidden faults in the internal circuit parts of integrated CML-logic-circuits include reducing the voltage difference between the high and low binary signals (logic swing) during testing so that the noise immunity is diminished The logic swing is reduced by varying reference voltages for constant current sources and differential amplifiers through the use of an integrated control circuit connected to influence reference voltage generators The control circuit is activated by reducing the supply voltage in a first embodiment or, in a second embodiment, by an external control signal

Switching control type thermal flow sensor

Abstract: A thermal flow sensor of a switching control type for measuring the flow rate of intake air of an internal combustion engine comprises a bridge circuit including temperature sensing resistors, a differential amplification circuit, a pulse generating circuit, a power supply control circuit and a resonance preventing circuit. The amplification circuit amplifying the output from the bridge circuit. The pulse generating circuit receives the output from the amplification circuit and generates a pulse train which has a time ratio corresponding to the output level of the amplification circuit. The power supply control means comprises a switching transistor which is turned on and off by the pulse train from the pulse generating circuit and a smoothing circuit which makes the output from the transistor continuous and supplies the continuous voltage to the bridge circuit. The resonance preventing circuit comprises a phase lag compensation circuit including a resistor and a capacitor connected in series between a differential amplifier of the amplification circuit, or a variable DC unbalanced voltage generator including a V/I converter which converts the voltage received from the bridge circuit to a current corresponding to the level of the received voltage and a resistor which converts the current output from the V/I converter to a voltage and outputs a variable DC unbalanced voltage thereacross, whereby the resonance phenomenon in the full range of the flow rate is prevented.