Abstract: In a battery state monitoring circuit including a voltage regulator therein and capable of controlling an internal circuit with a signal from a microcomputer, a circuit is provided in which the control of the internal circuit is available with the signal from the microcomputer in the case where the output of the voltage regulator is normal, and the signal of the internal circuit is decided regardless of the signal from the microcomputer in the case where the output of the voltage regulator is floating or in GND level.

Abstract: A smart battery that self-monitors and maintains information about itself that includes its state of charge, its need for maintenance, and for conditions that indicate that it has reached the end of its useful life and should be discarded. The information maintained by the battery is then either displayed on an on-board display or is communicated to another device on a communication bus. The state of charge quantifies the smart battery's ability to reliably deliver charge to a host device and is dynamically adjusted over the lifetime of the smart battery. The state of charge may not exceed a full charge capacity value maintained by the smart battery and initially set to an estimated value. This full charge capacity value is dynamically adjusted throughout the life of the smart battery using information accumulated and maintained by the smart battery that indicates the smart battery's actual performance during use and by using messages received from a battery maintenance and testing system.

Abstract: The temperature of a battery is detected by a temperature sensor, and a gassing voltage based on the temperature is determined by a gassing detection processing section at all times, and even during traveling, a full charge capacity calculation processing section estimates a full charge capacity on the axis of the full charge capacity from when the gassing occurred, from the remaining capacity at the time of gassing and a chargeable capacity.

Abstract: In a charge/discharge controlling semiconductor device for a secondary batter which can be used repeatedly even after detection of an abnormal charging current, the abnormal charging current is detected by using the resistance value of the on-state of a switching element without a current fuse for detection of the abnormal charging current.

Abstract: A control apparatus for a synchronous generator system has: a voltage instruction generator for generating voltage instructions (Vu*, Vv*, Vw*) based on an output power reference (P*) of the synchronous generator, currents (Iu, Iv) flowing through the synchronous generator and position information (&thgr;0, &ohgr;r) of magnetic poles of the synchronous generator; a zero crossing point detector for detecting a point that the voltage (Vu) of the synchronous generator passes through zero volt.; and a magnetic pole position calculator for calculating the information (&thgr;0, &ohgr;r) on the position of magnetic poles of the synchronous generator on the basis of the voltage instruction (Vu*) and the power reference (P*) when the synchronous generator is under the generation mode, and on the basis of an output signal of the zero crossing point detector when the synchronous generator is under the stand-by mode.

Abstract: A system and method for generating an AC power output signal from a DC power input signal. The system incorporates a transformerless DC-to-DC boost regulator including a plurality of boost stages coupled in series for receiving a DC input signal and producing a boosted DC power signal. The system further incorporates a DC-to-AC converter coupled to the transformerless DC-to-DC boost regulator, for receiving the boosted DC power signal and generating an AC power output signal. A control element is coupled to both the DC-to-DC boost regulator and the DC-to-AC converter. In at least one embodiment, the system and method for generating an AC power output signal from a DC power input signal are used in connection with an uninterruptible power supply.

Abstract: A DC-DC converter includes an oscillation circuit for oscillating at a predetermined frequency and generating a pulse with a predetermined pulse width, a reference voltage generating circuit for generating a reference voltage, means mounted in the reference voltage generating circuit for slowly rising the reference voltage, a switching circuit for chopping the current inputted from a DC primary electric power source in accordance with the pulse, and feedback control means for stopping/restarting the oscillation of the oscillation circuit on the basis of the voltage that the output of the switching circuit is smoothed and including the reference voltage with a detection voltage upon stopping control, so that the DC-DC converter having a soft starting function is provided with a simple structure and a compact size without utilizing a PWM circuit and a VCO.

Abstract: A non-insulating DC—DC converter is formed of a first semiconductor switching element for reducing a DC voltage from a high-voltage battery, a control circuit connected to the first semiconductor switch element for controlling pulses relative to the first semiconductor switching element, a second semiconductor switching element provided on an output side of the first semiconductor element, a capacitor connected between the first and second semiconductor switching elements in parallel, and a first control circuit connected to one end of the capacitor and an output side of the second semiconductor switching element. The first control circuit detects a voltage at the one end of the capacitor and a voltage on the output side of the second semiconductor switching element, and turns off the second semiconductor switching element if an overvoltage occurs at the one end of the capacitor. The damage of the internal elements due to an overvoltage or a reverse current is prevented.

Abstract: A generalized active reset switching network using a small choke, a pair of switches, and a capacitor is revealed. The application of the generalized active reset switching network to any of a wide variety of hard switching power converter topologies yields equivalent power converters with zero voltage switching properties, without the requirement that the magnetizing current in the main power choke be reversed during each switching cycle. In the subject invention the energy required to drive the critical zero voltage switching transition is provided by the small choke that forms part of the generalized active reset switching network. The application of the generalized active reset switching network to buck, boost, buck boost, Cuk, and SEPIC converters is shown. A variation of the generalized active reset switching network which adds a single diode to clamp ringing associated with the parasitic capacitance of off switches is also revealed.

Abstract: A digital control system for a voltage regulator calculates an estimated current representing a current passing through each inductor associated with a switching circuit. A desired total output current is calculated which will maintain an output voltage at the output terminal at a substantially constant level. Upper current limit and a lower current limit are calculated and the switching circuit to is caused couple an input terminal to an output terminal when the estimated current falls below the lower current limit, and caused to couple the output terminal to ground when the estimated current exceeds the upper current limit. Also, the estimated current may be compared to an individual current to trigger the switching circuit.

Abstract: A circuit and method for controlling current drawn from two different voltage sources while maintaining regulation of a fixed output voltage during controlled switching of different sleep states required by the microprocessor and system board.

Abstract: A dead time regulating apparatus is used in a switch mode power system. The apparatus, comprises a power MOSFET circuit with PMOS and NMOS devices. Driving means is connected for driving and for turning-on a delay in the MOSFETs. A time delay detecting means is connected for detecting dead time during MOSFET turn on and a pulse width comparing means is connected for receiving dead time signals and synchronous pulses for generating control signals. The control signals are directed to the driver means respectively for adjusting turn-on delays. The method of the invention provides precise dead time control in the MOSFET devices. The circuit drives the two MOSFET devices such that there is precise control of the dead time during on-off switching.

Abstract: A duty ratio setting circuit includes a triangular waveform oscillation circuit for generating a triangular waveform signal and an error amplifying circuit that compares a detection voltage with a reference voltage and generates a control voltage based on the difference between the compared voltages. A comparator is connected to the oscillation circuit and the amplifying circuit and compares the voltage of the triangular waveform signal with the control voltage, and generates a first rectangular waveform signal having a predetermined duty ratio based on the comparison. A pulse signal generator generates a pulse signal having a predetermined pulse width and which is synchronized with the triangular waveform signal. A logic circuit connected to the comparator and the pulse signal generator receives the first rectangular waveform signal and the pulse signal and generates a second rectangular waveform signal.

Abstract: An electrical circuit provides a fixed frequency switching regulator, having improved dynamic response, and a low count of external discrete elements. The circuit can be used at 100% duty cycle and does not require a minimum load or the components usually found in such circuits for compensation. A current source is used to charge a timing capacitor. A comparator is used in conjunction with a hysteresis circuit so that as the timing capacitor is charged the voltage on one input of the comparator rises until reaching a set input voltage level whereupon the timing capacitor is discharged to ground. A PWM latch logic element is used to control output to a control switch, a FET, so that positive going output pulses are received at an output terminal. A divider network between the output terminal and the timing capacitor along with a switch controlled by the PWM latch element are used for slope compensation for maintaining operational synchronization to the oscillator.

Abstract: A low dropout voltage reference having three gain stages and two feedback loops, an overall loop and a secondary loop, is disclosed. The overall feedback loop establishes a desired output voltage. The secondary feedback loop provides two benefits: (1) a broadband reduction of the output impedance to ensure stability under various loading conditions and (2) an improvement in power supply rejection. The first benefit ensures that the pole created by the load capacitance and the output impedance of the amplifier doesn't adversely affect the overall loop stability. The second benefit helps improve line regulation. The low dropout voltage reference does not rely on a capacitor connected to the output to properly compensate the overall feedback loop. Therefore, the reference will work properly for a wide range of load capacitance values.

Abstract: A current generator for delivering a reference current of which the value is proportional to the absolute temperature comprises first and second bipolar transistors (Q1, Q2) which are biased respectively by first and second current sources (I1, I2). The voltage difference between the emitters of the first and second bipolar transistors (Q1, Q2) is regulated to virtually zero volt by means of regulation means (RGMNS). Because of the presence of resistors (R1-R3) in series with the bases of the first and second bipolar transistors (Q1, Q2) instead of the presence of resistors in series with the emitters, the first and second bipolar transistors (Q1, Q2) can be chopped by switches without suffering from the disadvantageous effect of the undesired series resistances of the switches. For this reason by the chopping of the first and second bipolar transistors (Q1, Q2) the accuracy of the reference current is improved significantly.

Abstract: A dual-rated current transformer circuit has a first circuit which delivers a first current and a second circuit which delivers a second current. A current transformer is coupled to both the first and second circuits, wherein the transformer generates a current proportional to the current of each of the first and second currents.

Abstract: A fast voltage ramp generator comprises a chain of transistors connected collector to emitter in series, and biased to avalanched switching mode. A respective transformer secondary is connected to apply a switching pulse across the base emitter junction of each transistor of the chain to effect avalanche switching of the chain. The transformer secondaries are the secondaries of discrete transformers with respective primaries connected in series. The transformers are formed of ferrite beads having plated through holes constituting the secondaries of the transformers. The beads are threaded on an insulated conductor which constitutes the series connected primaries of the transformers.

Abstract: A device comprising of multiple quick connect/disconnect terminals used in conjunction with light emitting diodes connected to an integrated circuit using a single test probe, providing an efficient means when having to sort multiple conductors. The L.E.D's used in this device remain energized even after the test probe has been removed. This provides a useful alternative when having to sort multiple conductors within a particular wire bundle which may travel to a remote enclosure located away from it's origination point. Also this device is contained within a compact enclosure and operates from a small 9VDC power source, providing both convienence and safety to the panel assembler using this device.

Abstract: A device for locating the edges of wall studs includes a comparison circuit connected to each of three capacitive elements. As the device is moved along a wall, the comparison circuit monitors the relative charge time associated with each capacitive element, the charge times providing an indication of the relative capacitances of the three capacitive elements. Changes in the relative capacitances of the three elements as the device is moved along a wall are due to a change in the dielectric constant of the wall, which normally results from the presence of a wall stud behind the surface over which the device is moved. The comparison circuit uses differences in the measured relative capacitances of the first, second, and third capacitive elements to locate the edges of the stud.

Abstract: A combination ground and power source circuit tester device includes a cylindrical plug with a cone-shaped end that fits into a vehicle accessory receptacle. An attached body member engages the plug and retains first and second radially extending contacts that function to provide a connection with conductive studs that attach to leads to a circuit. A light bulb indicating that the circuitry is powered is retained in the body member and in a parallel circuit with the contacts.

Abstract: In an integrated-circuit tester which is provided with a contact failure analysis/storage part for counting and storing the number of failures occurring at each contact, an automatic stop part for deciding contact as defective based on the numbers of failures stored in the storage part and for stopping a handler, an automatic turn-OFF part by which, upon each operation of the automatic stop part, contacts having met the stop condition are automatically put in their unused state, and a defective contact display for displaying the number of contacts put in the unused state upon each automatic stop of the handler, an operator checks the number of contacts put in the unused state upon each automatic stop of the handler, then decides whether or not all the contacts used are to be replaced, and performs the necessary operations for resuming the test.

Abstract: An IC testing apparatus in which an accident occurring when a measurement part mounted on a test head is changed can be avoided. A type signal generating device 301 is provided on each of measurement parts so that a type signal TYPE can be sent from the type signal generating device 301 when a measurement part 300 is mounted on a test head 200. The type signal is read by a type signal reading device 102 provided in an IC tester 100. The type signal is transmitted to a handler 400 together with the number of simultaneous tests SUM extracted from a test program loaded in a main controller 101 of the IC tester. In the handler, a decision device 402 determines, based on the transmitted number of simultaneous tests and the type signal, whether or not the test program is proper and whether or not the arrangement of IC sockets set in the handler coincides with the arrangement of IC sockets of the measurement part.

Abstract: An electronic circuit for automatically compensating for errors in the output signal of a displacement sensor. The electronic circuitry includes an analog to digital converter for converting an analog output signal from a linear displacement type sensor. The digital output signal from the sensor is processed by a microcontroller which automatically compensates for errors in the output signal. Ideal values, stored in an electronic memory, are used for compensation.

Abstract: The present invention relates to a ferromagnetic-article sensor comprises a pathway-forming means for defining a pathway for a ferromagnetic-article; a magnet disposed adjacent to the pathway, forming a magnetic field; and a magnetic field detection element for detecting a part of a magnetic field formed by the magnet, the part of the magnetic field extending parallel to the plane of the magnetic field detection element; wherein the pathway-forming means, the magnet, and the magnetic field detection element are arranged such that the magnetic field detection element detects modification of magnetic fields by the ferromagnetic-article when the ferromagnetic-article travels through the pathway, distorting the magnetic field.

Abstract: A system for inspecting in-service gas distribution mains is disclosed. Coiled tubing technology and magnetic flux leakage (MFL) technology are integrated to produce a new inspection system for low pressure, in-service distribution pipelines. The coiled tubing provides the means by which an inspection module employing MFL technology is inserted into, moved through, and removed from an in-service pipeline. A portable inspection system can thereby be moved to a desired location on a trailer. The sensor module comprises a plurality of magnet assemblies each having a Magnet N out, a Magnet S out and a magnet core, the magnet assemblies being conical in shape and being arranged into a circular array. The magnet array diameter is smaller than that of a pipe to be inspected, thus defining a radial air gap. The magnet array being constructed and arranged to provide a magnetic circuit having sufficient strength so as to be operable through the radial air gap.

Abstract: A process for determining a thickness of a layer of electrically conductive material, any measurement errors are converted into dimensionless norm values with the aid of a normalization process. In this conversion, measurement errors, for example due to temperature drift and different electrical and magnetic properties of the base material of the carrying body can be largely eliminated. These norm values are converted into layer thickness values with the aid of a calibration curve.

Abstract: A meandering winding magnetometer (MWM) includes a meandering primary winding and at least one sensing winding or coil on a membrane to be pressed against a test surface. The membrane may be supported on a flexible carrier which is translatable into a probe. Abutments in the probe press the carrier against the test surface but allow the carrier and membrane to conform to the test surface. One MWM circuit includes meandering primary and secondary windings. The return leads from the secondary winding return to connector pads in close alignment with the test array, while leads from the primary winding are spaced at least one wavelength from the array. In another MWM circuit, individual sensing loops are positioned within the meandering primary winding. The MWM circuit may be provided on an adhesive tape which may be cut to length.

Abstract: Flexible eddy current probes that allow an inspector to interrogate the blade roots or disk slots of different types of blades and disks while using a limited number of probes. The probe includes a rectangular-shaped block assembly, a rectangular-shaped loading platform having a slot therein, and stabilizing slide rods that couple the loading platform to the block assembly. The slide rods are adapted to slide through the block assembly as the block assembly is urged towards the loading platform. The probe further includes a flexible coil within a flexible membrane that produces a magnetic field during the inspection. The flexible coil extends from the block assembly and remains within the device, that is, between the loading platform and the block assembly, when not deployed. When deployed, the flexible coil passes through the slot in the loading platform to allow contact with the surface being inspected. Outriggers within the probe guide the flexible coil onto the surface during deployment.

Abstract: The present invention provides a method for reducing the correlation time for global tumbling for analysis of proteins and other macromolecules by NMR spectroscopy. The method comprises placing a macromolecule, hydrated and without significant structure perturbation, within a reverse micelle in a suitable fluid medium of low viscosity. A high pressure NMR cell for use with the method of the present invention is also disclosed.

Abstract: An MRI system receives scan parameters from an operator which define the prescribed pulse sequence to be used in acquiring image data. The amplitude and slew rate of gradient pulses in the pulse sequence are calculated based on their prescribed areas to have optimal duration without exceeding physiologic gradient slew rate limits and to produce the pulse area required by the scan parameters.

Abstract: A system to correct edge blurring in an image reconstructed with partial k-space data includes a magnetic resonance imaging system, a computer, and a network. The magnetic resonance imaging system has a plurality of gradient coils positioned about a bore of a magnet to impress a polarizing magnetic field and an RF transceiver system and an RF modulator controlled by a pulse control module to transmit RF signals to an RF coil assembly to acquire MR images.

Abstract: A flexible, low-loss, low-capacitance, high-voltage, high-current, moderate-impedance, unshielded, balanced, rf-pulse transmission twinline is produced by etching parallel copper traces on opposite sides of a flexible substrate, spaced apart such that the distance between the conductors is greater than four times the substrate thickness and at least one of the conductors has a width greater than half of the separation between the conductors. A second, similar twinline may be etched on the same substrate beside the first twinline and paralleled at both ends with the first twinline to form a lower-impedance quadline such that alternate conductors in the quadline are on alternate sides of the substrate and have opposite current phases. Both surfaces may be coated with a thin, flexible dielectric to increase the voltage rating for a given conductor separation with minimal affect on propagation factor, attenuation constant, or flexibility.

Abstract: An MRI control system for controlling the operation of an MRI scanner from within an RF shielded MRI exam room in which the MRI scanner is located includes an MRI compatible infrared remote control device located within the MRI exam room for producing infrared control signals within the MRI exam room. An infrared receiver is positioned for receiving infrared control signals emitted by the infrared remote control device and producing electrical control signals in response thereto. An MRI controller located outside the MRI exam room is operatively connected to the infrared receiver for receiving control information. The MRI controller is operatively connected to the MRI scanner for controlling the MRI scanner and receiving scan information and the MRI controller operable to control operation of the MRI scanner in response to control signals emitted by the infrared remote control device based upon control information received from the infrared receiver.

Abstract: A magnet structure, particularly for Nuclear Magnetic Resonance imaging machines, and of the type having a bearing structure for means for generating magnetic fields inside a volume, a cavity or similar space, defined by the structure, is made to be modular at least for part of the bearing structure, and/or at least for part of the other construction elements.

Abstract: A diagnostic magnetic resonance apparatus has at least one component arranged inside a high-frequency shielded room, at least one other component arranged outside the high-frequency shielded room, and a control computer which is connected with the components via control lines. The control lines are constructed as a serial sensor/actuator bus comprising a first bus portion with electrical bus lines, and a second bus portion with optical bus lines. The optical bus lines are conducted into the high-frequency shielded room and are connected therein with the first component. The first bus portion is connected with the second bus portion via an electro-optical interface.

Abstract: A magnetic imaging apparatus includes an RF coil (F) in electrical communication with an RF signal generator (C) and a receiver (G) through an interface circuit (E). The signal generator transmits resonance excitation signals at one of at least two resonance frequencies, e.g. the resonance frequencies of hydrogen helium 3, fluorine, phosphorous, carbon, or xenon. During the transmit cycle, PIN diode (30) is forward biased forming a filter at a first resonance frequency, electrically isolating the receiver from first frequency excitation signals. Simultaneously during the transmit cycle, PIN diode (32) is forward biased forming a filter at a second resonance frequency electrically isolating the receiver from second frequency excitation signals. During a receive cycle, the diodes are reverse biased turning both filters into low impedance circuits around the first and second resonance frequencies allowing a received magnetic resonance signal to pass unimpeded from the RF coil to the receiver.

Abstract: In an MR imaging system, a method is provided for operating an MR gradient coil to provide a pulse sequence which comprises first and second sub-sequences. During the first sub-sequence, the coil is operated to produce a pair of diffusion-weighted imaging pulses, each having a gradient amplitude and a slew-rate. During the second sub-sequence the coil is operated to produce a train of echo-planar imaging pulses, each having a gradient amplitude which is selectively less than the amplitude of the diffusion-weighted pulses, and a slew-rate which is selectively greater than the slew-rate of the diffusion-weighted pulses. Thus, the invention is directed to a gradient system which can provide optimal performance for both diffusion-weighted imaging and echo-planar imaging, while using only a single coil for a given gradient axis.

Abstract: A method for detecting defective capacitors in a circuit and meters for that, based on passing alternative measuring current through capacitor to be tested. According to the first versions of the disclosed method, measuring signal is being applied between an envelop of the capacitor and one of its terminals to inject the measuring current inside the capacitor. That causes the current to flow through a dielectric between capacitor's plates and affect the current consumption depending on quality of the capacitor. An indicator of the meter displays one of voltage-current relationships that characterizes the capacitor. In this version the measuring current flows through a closed circuit.

Abstract: A double-speed tester for a microelectronic device, in which a plurality of recesses is formed on the circumference of a test plate at an interval of step, the recesses each accommodating a microelectronic device which is measured with the test plate rotating.

Abstract: A test unit for measuring crosstalk in twisted pair cable. The test unit has an output signal balance (OSB) circuit that compensates for parasitic capacitance at its output terminals. The OSB circuit has a voltage controlled capacitance connected in circuit with each output terminal to control the effective capacitance between the output terminals and ground. The bias voltage for the variable capacitances is calibrated by a method in which the voltage for one of the variable capacitors is held constant while the voltage for the other capacitor is varied in voltage levels. A test signal frequency sweep is applied to the test unit output terminals. First and second voltage values are obtained and a final bias voltage value is calculated from using these two values.

Abstract: The method for measuring the thickness of a material which transmits a detectable amount of microwave radiation includes irradiating the material with coherent microwave radiation tuned over a frequency range. Reflected microwave radiation is detected, the reflected radiation having maxima and minima over the frequency range as a result of coherent interference of microwaves reflected from reflecting surfaces of the material. The thickness of the material is determined from the period of the maxima and minima along with knowledge of the index of refraction of the material.

Abstract: Thickness of a wafer is monitored during grinding. A conductive plate is located below the wafer during grinding. One or more capacitive sensors are located above the wafer during grinding. A monitoring device monitors capacitance of the conductive plate and the capacitive sensor.

Abstract: A control system detects an electrical resistance change in a connector coupling a remote mounted temperature sensor to a control system. A control system determines the resistance of the sensor or the connector by selectively charging or discharging a capacitor through a unidirectional circuit element or the sensor. The control system is disclosed as controlling a water heater system, although such control systems may be used to control other systems using remote mounted sensors. A calibrating circuit is used to measure a transient response of an RC circuit, from which resistance can be derived.

Abstract: A linearization circuit includes a sensor circuit having a first terminal receiving an excitation voltage, and second and third terminals producing a sensor output voltage therebetween. A differential amplifier circuit produces a linearization current, and a scaling circuit operates to produce a scaled linearization current in response to the linearization current. A current direction switch circuit includes a fourth terminal receiving the scaled linearization current, a fifth terminal and conducting a correction current proportional to the linearization current, and a control terminal receiving a polarity control signal to determine the direction of flow of the correction current through the fifth terminal in response to the sensor output voltage.

Abstract: A microcircuit testing device, comprising an element for supporting a plurality of probes which are meant to make contact with pads of microcircuits to be tested which are formed on a wafer, the probes being directed substantially vertically to the supporting element, and connection elements suitable to connect ends of the probes, which are arranged opposite to ends for contact with the pads, to an element for providing an electrical interface between the connection elements and electric connector elements.

Abstract: The stylus support (10) has a center consonant with an origin of a plurality of axes, a stylus (13) on a side thereof and a vibrating/detecting element (12) disposed outside a surface perpendicular to an axis. A fitting portion (14) for fitting a probe body (15) is formed to the stylus support (10) and an aperture (17) is penetrated around the fitting portion (14) along the axis, so that the vibration of the stylus support (10) is isolated from a periphery of a fitted position of the probe body (15). Accordingly, an outer portion of the stylus support (10) outside the aperture (17) can be vibrated freely from the probe body (15) to allow the stylus (13) to vibrate sufficiently for improving accuracy.

Abstract: A method and system for probing with electrical test signals on an integrated circuit specimen using a scanning electron microscope (SEM) positioned for observing a surface of the specimen exposing electrically conductive terminals on the specimen. A carrier is provided for supporting the specimen in relation to the scanning electron microscope while a computer acquires an image identifying conductive path indicia of the surface of the specimen from the scanning electron microscope. A motorized manipulator remotely controlled by the computer manipulates a plurality of probes positionable on the surface of the specimen for conveying electrical test signals inside a vacuum chamber inner enclosure which houses the scanning electron microscope, the carrier, the motorized manipulator and the plurality of probes for analyzing the specimen in a vacuum. A feedthrough on the vacuum chamber couples electrical signals from the computer to the motorized manipulator and the plurality of probes.

Abstract: A micromechanical sensor probe for a scanned-probe tool includes a silicon cantilever and a silicon tip physically attached to the cantilever. The micromechanical sensor probe has a coating of a refractory metal silicide formed at least on the tip. Titanium silicide is preferred. The probe also has a layer of refractory metal nitride formed entirely over the refractory metal silicide.

Abstract: The present invention provides a method for determining a hot carrier lifetime of a transistor. In one embodiment, the method comprises the steps of determining an initial transconductance (gm1) of a transistor, and then, applying a stress voltage, which does not exceed a maximum breakdown voltage of the transistor, to the transistor to cause a transconductance degradation of the transistor, and then determining a subsequent transconductance (gm2) of the transistor. A hot carrier lifetime of the transistor can then be determined as a function of gm1 and gm2. Thus, the present invention provides a method in which the hot carrier lifetime is determined from sequential transconductance measurements without intervening, transistor characteristic tests that are typically conducted between the transconductance measurements that degrade the sensitivity of the gm measurement.