Showing papers on "Decoupling capacitor published in 1989"

Ac to dc converter with unity power factor

Abstract: An AC to DC converter comprises a bridge rectifier followed by a boost circuit The boost circuit includes an inductor, diode and load capacitor in series and a shunting switch connected to shunt the diode and load capacitor The control circuit for switching the shunting switch comprises a differential circuit, a multiplier and a duty cycle generator in a feedback loop which maintains a constant output voltage on the capacitor To eliminate the response to ripple on the output voltage, the differential circuit does not respond to voltages within a dead band

Selective application of voltages for testing storage cells in semiconductor memory arrangements

Abstract: A dynamic RAM is provided with a plurality of 1-MOSFET memory cells, each having a storage capacitor and a switching MOSFET coupled to one electrode of the storage capacitor. The other electrode of each of the storage capacitors is coupled to a switching circuit which controls the voltage which is applied to the capacitor. The switching circuit is, in turn, coupled to both a voltage generating circuit (which preferably provides a voltage of 1/2 Vcc) and a voltage supply circuit which is set to provide predetermined test voltages. Thus, by operating the switching circuit, a voltage of 1/2 Vcc can be applied to the memory cell capacitors during normal operation of the dynamic RAM, and the predetermined test voltages can be applied to the memory cell capacitors during a testing operation.

Variable-capacitance type sensor and variable-capacitance type sensor system using the same

Abstract: A constant-capacitance capacitor is series-connected with a variable-capacitance capacitor whose capacitance varies with the pressure. The other end of the variable-capacitance capacitor is connected to the ground potential terminal of a D.C. power source. The terminal voltage of the variable-capacitance capacitor is compared with a threshold voltage provided by the D.C. power source by means of a comparator. An output voltage of the comparator is stored into a memory in synchronism with a clock pulse signal. An output voltage of the memory is integrated by an integrator. An output voltage of the integrator is supplied to a buffer amplifier for lowering the signal source impedance with respect to the output voltage. An output voltage obtained from the buffer amplifier is fed back to the other end of the constant-capacitance capacitor and at the same time supplied to an output terminal.

Compensated capacitors for switched capacitor input of an analog-to-digital converter

Abstract: A semiconductor capacitor for use in an analog-to-digital converter includes two parallel connected capacitors with separate lower plates (44) and (46) fabricated of polycrystalline silicon and upper plates (52) and (54) also fabricated of polysilicon. The plates are separated by capacitive oxide dielectric structures (48) and (50). They are interconnected such that the lower plate (44) of one capacitor is connected to the upper plate (54) of the other capacitor and the lower plate (46) of the other capacitor is connected to the upper plate (52) of the first capacitor. With such a configuration, the odd ordered non-linearities contributing to the voltage coefficient errors are cancelled.

Magnetic neural stimulator for neurophysiology

Abstract: A magnetic neural stimulator is disclosed for the stimulation of biological tissue. The stimulator includes an inductive stimulation coil, an energy storage capacitor, a firing device and a charging circuit. The energy storage capacitor is charged by the charging circuit to a voltage level which is greater than the voltage level supplied to the charging circuit. The energy storage capacitor is partially discharged into the stimulation coil thereby producing a magnetic pulse. The charging and discharging of the capacitor is continuously performed so as to produce a plurality of high frequency magnetic pulses. The stimulation coil and the energy storage capacitor operate in a resonant manner under a control circuit which performs timing and gating functions.

Low impedance packaging

Abstract: A package for an integrated circuit is disclosed. The package includes a lead frame with an overlying dielectric layer. One or more conductive coupons are placed on the dielectric layer and act as multiple inductive paths for the power and ground lines. Decoupling capacitors may be attached between coupons.

Electronic wristwatch with generator

Abstract: An electronic wristwatch including an a.c. generator having an output which is rectified using a half-wave rectifier. The half-wave rectified output of the generator is stored in a capacitor serving as a secondary power supply. Booster circuitry is operable for increasing and decreasing the voltage of the secondary power supply which is then applied across an auxiliary capacitor used for powering the wristwatch. Additional circuitry provides a suitable voltage across the auxiliary capacitor for driving the watch when the voltage across the secondary power supply is at or below a predetermined level. A pair of detecting circuits detect the maximum and minimum permissible voltage levels of the secondary power supply and auxiliary capacitor.

Method and apparatus for testing an airbag restraint system

Abstract: A test circuit (100) for an airbag restraint system is disclosed and provides an accurate determination of the operativeness of a storage capacitor (130, 132) and calculates the resistance of inertia switch resistors (114, 118). The test circuit provides for parallel testing of the storage capacitor (130, 132) and inertia resistors (130, 132). The capacitor is tested by discharging and charging the capacitor. The values of the inertia switch resistors are determined by switching known resistive values in parallel with the inertia switch resistors. Based on the monitored voltage values during the switching, resistance values are calculated.

Electronic package with integrated distributed decoupling capacitors

Abstract: A semiconductor chip carrier includes a plurality of distributed high frequency decoupling capacitors as an integral part of the carrier. The distributed capacitors are formed as a part of the first and second layers of metallurgy and separated by a layer of thin film dielectric material built up on a substrate. The distributed capacitors are positioned to extend from a ground pin of one of the layers of metallurgy to a plurality of mounting pads which are intergral parts of the other of the layers of metallurgy. A semiconductor chip is mounted to the mounting pads and receives electrical power and signals therethrough. The distributed capacitors decrease electrical noise associated with simultaneous switching of relatively large numbers of off-chip drivers which are electrically connected to the semiconductor chip.

Stable high voltage pulse power supply

Abstract: A high voltage stable pulse power supply 10 which includes a first power supply 11, ; a first capacitor 12 ; connected in parallel with the first power supply, a first switch 13 mounted in parallel with the first capacitor 12. The switch 13 selectively connects the first capacitor 12 to a load 14 so that the first capacitor 12 may discharge therethrough. An anti-droop network 15 is connected in series with the first capacitor 12. The anti-droop network 15 cancels droop in the output of the first capacitor 12 as it discharges into the load 14. In a specific embodiment, the anti-droop network 15 includes an inductive element 42 connected in series with the first capacitor 12 which is charged just prior to the activation of the first switch 13. The inductor 42 provides energy to compensate for the droop in the energy supplied by the first capacitor 12. In a more specific embodiment, the first switch 12 is implemented with a Crossatron switch 31 and a modulating anode electron gun 32 to minimize system control voltages. The present invention achieves coherent emission in a free electron laser, for long pulses, allowing selection of single modes.

Conversion circuit for limiting inrush current

Abstract: A conversion circuit is provided which includes a negative temperature coefficient resistance between a rectifier and a storage capacitor to limit inrush current when power is applied to the circuit after a power interruption of a relatively long duration. When power is resumed after a short term power interruption and the resistance of the negative temperature coefficient resistance is still low, inrush current is limited by disconnecting a load from the conversion circuit immediately upon the occurrence of the power interruption to maintain the charge on the storage capacitor for the duration of the interruption. A boost regulator unit is provied between the negative temperature coefficient resistance and the storage capacitor to provide a regulated direct current potential across the capacitor which is not responsive to input power variations.

A memory cell with capacitance for single event upset protection

Abstract: A compact capacitor for use in a small memory cell in high density memories is disclosed. Such a capacitor in the cross-coupling of cross-coupled inverters in the memory cell improves single event upset hardness. The subject capacitor in its preferred embodiment is a MOS capacitor with both n+ and p+ connections to the capacitor channel so as to maintain a relatively high capacitance for both positive and negative capacitor gate voltages.

Rotary speed sensor with base line compensation of Hall cell output signal

Abstract: A rotary speed sensor system uses a permanent magnet and a Hall cell sensitive to the changing tangential component of magnetic field caused by the interrupted surface profile of a rotary element. In order to avoid anomalies caused by the variation of the base value of the tangential component of magnetic field, the output of a differential amplifier fed by the Hall cell is connected to a voltage averaging circuit which stores the average voltage of the output on a single capacitor. The output of the differential amplifier and the voltage across the capacitor are respectively coupled to the differential inputs of a Schmitt trigger exhibiting hysteresis. The Schmitt trigger thereby establishes operate and release points relative to the average voltage signal. The voltage averaging circuit is a non-linear circuit in which the voltage across the capacitor is fed back to the negative input of an operational amplifier. A power-up circuit is also provided for rapidly charging the capacitor initially to approximately the average voltage.

Current limiting scheme for the AC input circuit to a switch mode power supply

Abstract: A DC switch mode power supply operating from an AC input power source typically has an input stage which includes a rectifier for rectifying the AC input power waveform to provide a DC voltage to the switch mode power supply. This rectifier includes a capacitive storage circuit for storing the DC power to be supplied to the switch mode power supply. To protect the circuit against current surges during start-up, normally an open relay is provided in parallel with a current limiting resistor. This resistor can burn out under some circumstances. This invention replaces the resistor with a capacitor divider circuit containing at least one capacitor in series between the storage capacitor and one of the terminals from the input power supply. A second capacitor can also be provided in parallel with the storage capacitor and one of the diodes of the rectifier. Another diode of the rectifier is in series with the storage capacitor. The resulting circuit limits the initial current surge to the storage capacitor and also functions as a charge pump to make possible the storage of a charge on the storage capacitor greater than the peak input voltage.

Linear capacitance displacement transducer

Abstract: A linear capacitance displacement transducer for measuring absolute displacement is formed from a coaxial variable capacitor and a precision capacitance measuring electronic circuit. The plates of the coaxial capacitor are attached to the members of an assembly whose displacement relative to one another is to be determined. Linear displacement of the members causes a linear displacement between the capacitor plates which is reflected in a linear capacitance change. A capacitor controlled oscillator utilizes the coaxial variable capacitor at its input. The capacitor controlled oscillator whose period of oscillation is been determined by the capacitance and locked in phase with changes of capacitance is utilized as a precision measure of capacitance. The period of the square wave output of the oscillator is a linear function of the capacitance of the variable capacitor at any time. The transducer may be adapted to determine the absolute position of a piston rod in a hydraulic cylinder.

Depletion mode chip decoupling capacitor

Abstract: An integrated cirucuit is provided with a depletion mode filter capacitor, which reduces voltage spiking, while at the same time avoiding latchup problems caused by the capacitor. The depletion mode capacitor has a barrier layer which is doped to an opposite conductivity type as the integrated circuit's substrate, achieved by doping to provide an opposite difference from four valence electrons as the substrate. The barrier is formed as a part of a CMOS process, in a manner which avoids additional process steps. The capacitor is formed with one node connected to ground or substrate, and the other node directly to a power bus. The capacitor is located on open space available on the whole siliocn chip (memory as well as logic chip), particularly directly underneath the metal power bus to achieve an on-chip power bus decoupling capacitor wth capacitance in excess of 0.001 μF.

Integrated circuit package

Abstract: Integrated circuit package comprising a power supply distribution wiring and a chip interconnection signal wiring both formed on the top surface of a passive semiconductor interconnection carrier (2) in which a power supply decoupling capacitor is implemented. Spaced wells (4) of a first conductivity type are provided in the surface of said carrier of a second conductivity type. The power supply distribution wiring comprises first and second conductive lines (5,6) within a first wiring level (WL1). Said first conductive lines (5) are deposited on the surface areas of said wells (4) in an ohmic contact relationship and said second conductive lines (6) are deposited on the surface areas of said carrier (2) between said wells (4) in an ohmic contact relationship. Said first and second conductive lines are connected to first and second terminals of the power supply, respectively, so that the junction capacitance between said wells (4) and the carrier material (2) embedding said wells forms said decoupling capacitor. At least one active integrated circuit chip (1) is mounted and electrically connected to the passive semiconductor interconnection carrier (2).

Noise reduction in CMOS driver using capacitor discharge to generate a control voltage

Abstract: A pull-up or pull-down transistor in an output buffer or the like is controlled to limit dI/dt and thus reduce noise. This control employs a series transistor in the driver circuit which has a modulating voltage applied to its gate. This modulating voltage is generated in a circuit which uses precision-timed clocks as a reference so that variations in electrical parameters (process, temperature and power supply dependent) will not cause variation in circuit noise. A dummy driver circuit is used to discharge a capacitor at a rate dependent upon the modulating voltage, and the capacitor voltage is compared with a reference at a time determined by the precision clock. The result of the comparison is used to increment or decrement the modulating voltage.

Short-resistant decoupling capacitor system for semiconductor circuits

Abstract: A decoupling capacitor system for improving the reliability of digital logic circuit boards such as single inline memory modules which use surface-mount decoupling capacitors. The system comprises one or more units of two or more series-connected capacitors connected between the chip supply voltage (Vcc) input and the chip ground (Vss) connection. Given no change in the reliability of the individual capacitors, the reliability of a circuit board can typically be improved by several order of magnitude.

Electronic ballast for fluoroscent lamps

Abstract: Electronic ballasts are essentially composed of a series connection of a harmonic filter that has its input side connected to the AC line, a rectifier and an inverter to which is connected at least one load circuit composed of a series circuit of an inductor and a parallel circuit composed of a fluorescent tube and a capacitor. When a high electric tolerance is required of such a ballast in view of a desired increase in the power factor, standard circuit designs required a relatively expensive storage capacitor that smooths the AC rectified line voltage. In order to be able to use a storage capacitor that has a lower electric tolerance in comparison to the required voltage tolerance of the ballast, a storage capacitor is incorporated into one of the two capacitor branches of the inverter which is composed of a switch bridge arrangement having two switch branches and two capacitor branches, this storage capacitor being connected in series with the actual load.

Digital-to-analog converter using switched capacitor and transverse filter

Abstract: The converter incorporates a transversal filter. The filter delays are implemented in digital form prior to conversion into analog signals (preferably using switched capacitor techniques). One form of switched capacitor converter (with or without filtering) employs a single capacitor, common to a plurality of bits, appropriate weighting of the bits being achieved by controlling the switching.

Control circuit using a sulphonated fluorocarbon humidity sensor

Abstract: A control circuit (1) for use in a humidifier (H). A capacitor functioning as a humidity sensor (55) includes a sulphonated fluorocarbon material acting as the dielectric (57) of the capacitor. The material is sandwiched between sheets (59a, 59b) of a screen material which act as plates of the capacitor. An RC oscillator (53) has a variable frequency output and incorporates the capacitor. Changes in the dielectric value of the material due to sensed changes in humidity produce changes in the oscillator output frequency. A DC voltage is supplied to the oscillator. The amount of voltage impressed on the sensor at relatively high-humidity levels is controlled to prevent leakage currents caused when the material is exposed thereto. The generation of such leakage currents otherwise adversely effects sensor operation. Operation of the circuit to control operation of the humidifier is also described.

Power conversion system including an improved filter for attenuating harmonics

Abstract: For connecting the d-c terminals of a voltage-source inverter to a direct current (d-c) power source, a d-c link capacitor is connected directly between the d-c terminals, a line capacitor is connected in parallel with the d-c link capacitor, and a series inductor is connected between the line capacitor and the source. A dynamic brake resistor and an electric power chopper are connected in series with one another across the line capacitor. Between the two capacitors, no inductance is provided but a resistor is inserted in the braking current path during electrical braking operation of the inverter.

Surface mounted decoupling capacitor

Abstract: A decoupling capacitor (40) is mounted on a thin auxiliary board (20) and connected by metallization traces (37, 33) on the board to a single pair of plug-in contacts (50, 51) press-fitted into a pair of apertures (36) in a pair of integral tabs (31, 32) extending from the board (30). The auxiliary board (20) and capacitor (40) height is not more than about 0.070 inches. The plug-in contacts (50, 51) are pluggable into a pair of sockets in a printed circuit board. The auxiliary insulative board (20) with its attached capacitor (40) is sandwiched between a surface of a printed circuit board (12) having a plurality of sockets, and the underside of a dual-in-line (DIP) integrated circuit package (11). At least two leads (15a, 14x) of the DIP package (11) are inserted into the pair of insertable contacts (50, 51) in the auxiliary insulative board (20) while the remainder of the DIP package leads are inserted directly into other sockets in the printed circuit board (16a, 16x, 17a, 17x). In one embodiment, other DIP leads pass through clearance holes (69, 68) in a second pair of integral tabs (63, 65). Another embodiment provides for redundant capacitors each connected to separate pairs of contacts (82, 83; 84, 85) on the auxiliary board (81) for interconnection of two ground leads and two power leads of the DIP to respective PC board sockets.

Measuring and analyzing the impact of voltage and capacitor control with high speed data acquisition (distribution system)

Abstract: Experimental results on the effects of capacitor switching on feeder operating variables as measured in the substation by a high-speed data acquisition system are presented. Consistent with the modeling of feeder loads as constant power, the switching in of a capacitor bank to improve power factor results in decreased reactive power injection and increased phase voltage. However, a reduction in real power injection reflecting reduced line losses is not observable at the substation. Similarly, the switching out of a capacitor bank results in increased reactive power, decreased phase voltages, and decreased real power. Analysis of the experimental results, using voltage-sensitive load models shows that while feeder losses are reduced following feeder power factor correction, the attendant improvement in voltage profile results in an increase in load that exceeds the amount of loss reduction. Consequently, distribution system operators using supervisory control and data acquisition systems will not be able to observe the loss reduction associated with capacitor switching to improve power factor. >

Semiconductor device using MIS capacitor

Abstract: A MIS capacitor to be implemented in a semiconductor device employing various or predetermined circuits, has a dielectric side electrode which is in contact with a buried layer provided on a semiconductor substrate through a dielectric film and a buried layer-side electrode connected to the buried layer. The buried layer-side electrode of the MIS capacitor is connected to a low-impedance side of the circuit employed therewith. This structure, when connected as such, is capable of reducing the influence of noise attributed to an α-ray and thereby operating the circuit stably. The semiconductor device using a MIS capacitor invention is adaptable to an emitter follower circuit and various logic circuits for preventing malfunction resulting from α-ray radiation.

Ac motor drive with improved voltage-source inverter

Abstract: A bridge between the inductor and the capacitor of the DC-Link of a voltage-source inverter AC motor drive includes a GTO (or transistor) device used for forced-commutation in the regenerating mode, while the current is controlled ON and OFF according to a duty-cycle defined by an hysteresis circuit to hold the current flowing into the inductor to a magnitude which establishes a boost on the capacitor voltage, so that in the motoring, as well as the regenerating mode of operation, the voltage of the capacitor is kept constant and higher than upon the converter output.

Strobe alarm circuit

Abstract: A strobe light circuit is provided for flashing a strobe flash unit at a desired frequency. An inductor is repetitively connected and disconnected across a d.c. power line by a switch means so that energy is stored in the inductor during the period when the circuit is complete. The flash unit and a capacitor are connected in parallel so that the capacitor can discharge its stored energy to the flash unit when the voltage across the capacitor exceeds the threshold firing voltage of the flash unit. The parallel combination of the flash unit and the capacitor is in turn connected in series with a diode, and the resulting series circuit is connected across the inductor with the diode being connected in polarity such that current will not flow from the power line through the flash unit or the capacitor. The switch means is repetitively cycled so that over the period of each flash cycle the energy supplied to the inductor from said power line while the switch is closes and thence to the capacitor while the switch is open will substantially equal that amount of energy required to charge the capacitor to the threshold firing voltage of the flash unit.

Motor control fail-safe circuit

Abstract: A fail-safe circuit is disclosed for use with an intermittently operated d.c. motor (10) connected by means of a circuit breaker (14) to a power supply (12), wherein a control circuit (21) provides control pulses intermittently to the motor. The fail-safe circuit includes a capacitor (38) which is charged when the drive pulses are being applied to said motor, and is discharged when the drive pulses are not being applied to said motor. A reference voltage (34G) is generated and compared with the voltage stored on said capacitor. When the voltage on the capacitor exceeds the reference voltage, the circuit breaker is caused to interrupt the power supply to the motor.