Bias tees, according to certain embodiments of the present invention, include switches in the AC signal path, the DC signal path, or both, to improve the capability of the bias tees to be used for high impedance AC measurement, low current DC measurement, or both. Optical control of the switches, as well as control of the switches using a DC bias present within the AC signal input to the bias tee, is described. Including a set of diodes into the DC signal path, rather than a switch, provides enhanced capability of the bias tee to be used for high impedance AC measurements.
A circuit structured to drive an isolated high speed voltage metal-oxide-semiconductor field-effect transistor (MOSFET) switch, including a first MOSFET and a second MOSFET configured to operate as a switch, a capacitor, a charging component in parallel with the capacitor, a first switch in series with the charging component, and a second switch in parallel with the charging component and the capacitor. The stored voltage in the capacitor is sent to the gates of the first MOSFET and the second MOSFET when a second switch is open and a first switch is closed.
H03K 17/0412 - Modifications for accelerating switching without feedback from the output circuit to the control circuit by measures taken in the control circuit
H03K 17/687 - Electronic switching or gating, i.e. not by contact-making and -breaking characterised by the use of specified components by the use, as active elements, of semiconductor devices the devices being field-effect transistors
H03K 17/689 - Electronic switching or gating, i.e. not by contact-making and -breaking characterised by the use of specified components by the use, as active elements, of semiconductor devices the devices being field-effect transistors with galvanic isolation between the control circuit and the output circuit
H03K 17/0416 - Modifications for accelerating switching without feedback from the output circuit to the control circuit by measures taken in the output circuit
H03K 17/785 - Electronic switching or gating, i.e. not by contact-making and -breaking characterised by the use of specified components by the use, as active elements, of opto-electronic devices, i.e. light-emitting and photoelectric devices electrically- or optically-coupled controlling field-effect transistor switches
H03K 17/081 - Modifications for protecting switching circuit against overcurrent or overvoltage without feedback from the output circuit to the control circuit
An active shunt source-measure unit (SMU) circuit can include an SMU or power supply having an active shunt circuit that is integrated with the current measuring sub-circuit of the SMU circuit. The active shunt circuit may be active during voltage sourcing of the SMU circuit and deactivated during current sourcing of the SMU circuit.
G01R 1/20 - Modifications of basic electric elements for use in electric measuring instrumentsStructural combinations of such elements with such instruments
A device with low dielectric absorption includes a printed circuit board (PCB), a component connection area including a first conductor layered on a top surface of the component connection area and a second conductor layered on a bottom surface of the component connection area, an aperture surrounding the component connection area, a low-leakage component connecting the component connection area to the PCB across the aperture, and a guard composed of a third conductor at least substantially surrounding the aperture on a top surface of the PCB and a fourth conductor at least substantially surrounding the aperture on a bottom surface of the PCB.
A method for compensating for a dielectric absorption effect in a measurement configuration during measurements by an instrument having measurement terminals includes providing a feedback loop in the instrument, the loop having a gain adjustment and a simulation impedance and being adapted to provide a signal counter to the dielectric absorption at the measurement terminals; applying a transient calibration signal to the test terminals for at least two values of the gain adjustment; measuring a response to the calibration signal for each of the at least two values; and determining an operating value of the gain adjustment based on the measured responses. The operating value is used for subsequent measurements by the instrument, the simulation impedance modeling the dielectric absorption characteristics of the measurement configuration.
An isolated DC-to-DC switching power supply includes an isolation transformer having a magnetic core, a first winding around the magnetic core, a first winding-shield around the magnetic core, a second winding-shield within the first winding-shield, and a second winding within the second winding-shield. There is no direct coupling between the first winding and the second winding since the second winding is enclosed within the second winding-shield and the second winding-shield is enclosed within the first winding-shield.
A system may include two input terminals, e.g., HI and LO, and a floating circuit that is physically separate from the input terminals and includes a gain amplifier. The floating circuit can be surrounded by a conductive enclosure that is electrically connected to the second input terminal. The floating circuit can further switch between input signals received from the first and second input terminals to the gain amplifier and the floating circuit ground.
G01R 1/30 - Structural combination of electric measuring instruments with basic electronic circuits, e.g. with amplifier
G01R 17/16 - AC or DC measuring bridges with discharge tubes or semiconductor devices in one or more arms of the bridge, e.g. voltmeter using a difference amplifier
G01R 19/00 - Arrangements for measuring currents or voltages or for indicating presence or sign thereof
G01R 19/25 - Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
G01R 15/22 - Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using light-emitting devices, e.g. LED, optocouplers
A method for verifying the adjustment for the purpose of calibration of an impedance meter having at least a first and a second measurement range includes measuring within the first range a first measured value of a test impedance; measuring within the second range a second measured value of the test impedance; and comparing the first and second measured values to verify the calibration of the impedance meter.
G01R 31/27 - Testing of devices without physical removal from the circuit of which they form part, e.g. compensating for effects due to surrounding elements
An RF testing method and system by which a DC measurement pathway can also act like a properly terminated RF pathway. Achieving this requires that the output HI, LO, and Sense HI conductors are terminated in a frequency selective manner such that the terminations do not affect the SMU DC measurements. Once all SMU input/output impedances are controlled, as well as properly terminated to eliminate reflections, the high-speed devices will no longer oscillate during device testing, so long as the instruments maintain a high isolation from instrument-to-instrument (separate instruments are used on the gate and drain, or on the input and output of the device). The output of HI, LO and Sense HI conductors are coupled to various nodes of the DUT via three triaxial cables, the outer shieldings of which are coupled to each other and to an SMU ground.
A power envelope controller configured for use with an amplification stage and method are disclosed. The power envelope controller includes voltage feedback input circuitry configured to receive a voltage feedback signal representing an internal voltage drop across the amplification stage and current feedback input circuitry configured to receive a current feedback signal representing an output current of the amplification stage. An analog multiplier is configured to generate an internal power dissipation signal representing the internal power dissipation of the amplification stage based on the voltage and current feedback signals. A comparator circuit is configured to compare the internal power dissipation signal to a power threshold and generate a power control error signal when the internal power dissipation of the amplification stage exceeds the threshold.
A multiplexor includes an output having a characteristic impedance; a first input having a characteristic impedance equal to the output characteristic impedance; a second input; a first switch path including a first switch operable to connect/disconnect the first input center conductor and the output center conductor; a first input conductive path adjacent to the first switch path and being operable to provide the output characteristic impedance; a second switch path including a second switch operable to connect/disconnect the second input first signal conductor and the output center conductor; and a third switch path including a third switch operable to connect/disconnect the second input second signal conductor and the output intermediate conductor, the third switch path being operable to guard the second switch path when the third switch path is provided with a guard voltage.
An opto-isolated amplifier and method are disclosed. The amplifier includes an input node configured to receive an input to be amplified. A pair of opto-isolators are coupled between an input node and an output node. The opto-isolators are configured to create gain between the input node and the output node. An amplification stage is coupled to the opto-isolators. The amplification stage includes an input coupled to the output node and an output configured to generate an amplified output. The opto-isolator outputs may be configured to generate a difference current. The input of the amplification stage may have a high impedance compared to an impedance at the output node, the difference current being directed at the high input impedance input of the amplification stage to generate a gained voltage.
An apparatus for testing a DUT includes a pulsed signal source; a hard current-limiter adapted to be operated in series relationship between the pulsed signal source and the DUT; and a voltage sensor adapted to sense a voltage across the DUT in response to the pulsed signal source.
A DC-AC probe card for testing a DUT includes: a plurality of probe needles, each probe needle having a distal end for contacting said DUT; and a plurality of connection pathways operable to connect test instrumentation to the probe needles, wherein each connection pathway provides both a desired characteristic impedance for AC measurements and a guarded pathway for DC measurements between respective test instrument connections and probe needles.
G01R 31/00 - Arrangements for testing electric propertiesArrangements for locating electric faultsArrangements for electrical testing characterised by what is being tested not provided for elsewhere
G01R 31/02 - Testing of electric apparatus, lines, or components for short-circuits, discontinuities, leakage, or incorrect line connection
A system for making high frequency measurements on a DUT includes a high frequency measurement instrument; a plurality of DUT probes; a first coaxial cable having a center conductor and a coaxial conductor for connection between the instrument and a first DUT probe; and a second coaxial cable having a center conductor and a coaxial conductor for connection between the instrument and a second DUT probe, at least one of the first and second cables being selectively shortable between the respective center conductor and coaxial conductor at a location near the respective DUT probe.
A method for operating a measurement system having an interconnect between the measurement system and a device under test (DUT), the interconnect exhibiting voltage drops during measurements of the DUT, includes applying a test signal to the DUT through the interconnect, the test signal having a system value at the measurement system; measuring a resulting DUT value at the DUT; adjusting the system value according to the resulting DUT value to produce successive desired DUT values at the DUT; and using the successive DUT values to measure an electrical characteristic of the DUT.
An electronic instrument having in its circuitry a specific solid state switch that exhibits detrimental current leakage at elevated temperatures, a variable voltage device in the instrument connected to the specific switch, the variable voltage device being capable, at an experimentally determined voltage setting, of zeroing out the leakage current in the specific switch, the variable voltage device being set at a voltage setting determined experimentally using said specific switch at an elevated temperature thereby temperature compensating said specific switch.
A transmission line impedance compensation method includes the step of providing a measurement device that is adapted to source a test signal having a frequency to a device under test and to determine a corresponding impedance of the device under test using an auto-balanced bridge technique. A first transmission line, a second transmission line, a third transmission line, and a fourth transmission line are connected to said measurement device. An end of the first transmission line is connected to an end of second transmission line. An end of third transmission line is connected to an end of fourth transmission line. A combined phase delay of the connected first and second transmission lines, and a combined phase delay of the connected third and fourth transmission lines, are measured by the measuring device. The device under test is connected to the first transmission line, the second transmission line, the third transmission line, and the fourth transmission line after measuring the phase delays. The corresponding impedance of the device under test is determined based on both of the phase delays.
Provided is a relay that includes first and second contacts that are selectively connectable for closing an electric circuit. A coil wound around the contacts along a longitudinal axis can generate a magnetic field that connects the contacts in one of an energized or de-energized state and disconnects the contacts in the other of the energized or de-energized state. A first electrically conductive shield is provided adjacent to a first end of the relay and electrically connected to the first contact, and a second electrically conductive shield, the second electrically conductive shield being electrically connected to the second contact. The first electrically conductive shield extends at least partially around the first contact and the second electrically conductive shield extends at least partially around the second contact. The second electrically conductive shield is substantially coaxial with the first electrically conductive shield and separated a distance apart from the first electrically conductive shield along the longitudinal axis.
A circuit for alternatively controlling a current through a device and permitting measurement of a voltage across the device or controlling a voltage across the device and permitting measurement of a current through the device includes a sense impedance in series combination with the device; a buffer communicating with a common point between the sense impedance and the device; a current output stage; and a voltage output stage. When the circuit is controlling the current through the device, the voltage output stage forces the common point to a virtual ground and the current output stage forces a desired current through the device in response to a signal from the buffer. When the circuit is controlling the voltage across the device, the current output stage forces the common point to a virtual ground and the voltage output stage forces a desired voltage across the device in response to the signal from the buffer.
A measurement system with selectable feedback paths includes a DUT interface including a first and a second DUT sensor, the first sensor being connected to a first feedback path for providing a measure of a first DUT characteristic, the second sensor being connected to a second feedback path for providing a measure of a second DUT characteristic, the sensors having a shared reference path and each feedback path including a set point adjustment; a differential amplifier system including differential inputs and differential outputs, the differential outputs being applied to the DUT interface; and a multi-pole switcher for connecting the differential inputs to either the first feedback path and the reference path or to the reference path and the second feedback path, respectfully. The first feedback path is selected to produce a desired first DUT characteristic or the second feedback path is selected to produce a second desired DUT characteristic.
A power supply includes: a switching amplifier including an input and an output, the amplifier input being adapted to be powered by an electrical power source; a transformer including a primary and a secondary winding on a magnetic core, the number of winding turns being chosen to limit magnetization levels to avoid magnetic saturation while maximizing winding spacing, the transformer primary winding being in communication with the amplifier output; a rectification system in communication with the transformer secondary winding, the rectification system providing a DC power output; and a controller. The controller monitors the DC power output and adjusts the switching amplifier in response to the monitoring to provide a desired power output characteristic.
H03F 1/04 - Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in discharge-tube amplifiers
H03F 1/34 - Negative-feedback-circuit arrangements with or without positive feedback
25.
Phase-gain calibration of impedance/admittance meter
A method for calibrating an impedance/admittance meter for measurements of a DUT includes measuring a pure capacitance at a desired frequency; using the capacitance measurement to establish the phase response of the meter; measuring the admittance value of a resistor with the meter at the desired frequency, the resistor having a known DC conductance and being known to primarily exhibit parallel capacitive frequency dependency; and adjusting the gain of the meter to provide the known DC conductance as the real component of the admittance value.
A circuit for controlling a voltage across a device and permitting measurement of a current through the device includes a sense impedance in series combination with, the device, a sensed voltage measured across the sense impedance being representative of the current through the device; a capacitive stability element in parallel combination with the sense resistance, the capacitive stability element being virtually absent by connection to a virtual version of the sensed voltage when the device has a first capacitance and being present when the device has a second capacitance, the second capacitance being larger than the first capacitance.
A method for controlling a measurement system includes providing a variable bandwidth DC bias loop for biasing a DUT; providing an AC measurement loop for measuring AC parameters of the DUT; disabling the AC measurement loop and selecting a high bandwidth for the DC bias loop when rapid changes to the DC bias are to be made; and selecting a low bandwidth for said DC bias loop and enabling the AC measurement loop when AC measurements of the DUT are to be made.
G01R 31/26 - Testing of individual semiconductor devices
G05B 13/02 - Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric
28.
Measurement instrument with synchronized interference signals
An instrument for measuring electrical parameters includes a measurement section having a measurement aperture; and a support section providing at least one of power and digital control for the measurement section. The support section has an interference signal frequency, wherein the interference frequency is an integer multiple of the reciprocal of the measurement aperture and the measurement aperture and the interference signal are phase-locked. As a result, the effect of the interference signal on electrical parameters measured is minimized.
A measurement system for testing a DUT includes a plurality of procedures for performing test functions, each procedure having a phase variable; a task queue where the procedures are entered in the task queue with a sign-up value of the phase variable; and a multiphase task executor that arranges the procedures in the queue in response to the sign-up value. The executor changes the phase variable to an execution value and executes the procedures in the task queue after the phase variable has the execution value.
A method for verifying the adjustment of a plurality of measurement instruments includes measuring a first value of an un-verified test value of a parameter with a first measurement instrument; measuring a second value of the same un-verified test value of a parameter with a second measurement instrument; comparing the first value with the second value; and determining an adjustment verification state based on the comparison.
A method and apparatus for measuring a pulsed I-V characteristic of a DUT that has a signal terminal and a return terminal includes connecting a pulse unit between the signal and return terminals, the pulse unit having a pulse source and a pulsed current measuring device; pulsing the signal terminal with the pulse unit; measuring a pulsed current through the signal terminal with the current measuring device in response to the pulsing; and outputting, storing, displaying, or otherwise using the current measurement.
An AC impedance measurement system is used for measuring the impedance of a DUT. A measured voltage is applied to a first DUT terminal by a first digital to analog converter, the voltage appearing at the second terminal of the DUT is monitored through an analog to digital converter and forced by a second digital to analog converter to a desired negligible value, and a digital controller determines the impedance of the DUT from the measured voltage and the current necessary to force the voltage appearing at the second terminal to the desired negligible value.
A toroidal step-up or step-down transformer includes a toroidal magnetic core, a primary formed from a plurality of primary windings, and a secondary formed from a plurality of secondary windings. Parallel connected windings are added to at least one of the primary and secondary to make the number of primary windings equal to the number of secondary windings, the primary and secondary windings being arranged symmetrically around the core.
A range-changing circuit for a measurement device having a desirable range includes an array of graduated impedances. And amplifier supplies an electrical voltage to at least one of the impedances of the array. A voltage sensing and limiting switch is provided in a feedback path of the amplifier. The switch limits said electrical voltage supplied to said at least one of the impedances in response to a sensed voltage that is sensed by the switch. An electrical voltage in the desirable range is developed across a different one of the impedances of the array based on an operation of the switch.
A measurement instrument for measuring the impedance of a device under test (DUT) includes a first source of either a voltage or a current and a second source of either a voltage or a current, wherein the first source is connectable in a first feedback relationship with the DUT and the second source is connectable in a second feedback relationship with both the DUT and the first source. The first and second sources are operated respectively as a current source responsive to the current through the DUT and a voltage source responsive to the voltage across the DUT or operated respectively as a voltage source responsive to the voltage across the DUT and a current source responsive to the current through the DUT. The second feedback relationship has a narrower bandwidth than the first feedback relationship. The resulting voltage across the DUT and the current through the DUT establish the measured impedance of the DUT.
A triaxial cable having a center conductor; an outer shield conductor coaxial with the center conductor; and an inner shield conductor coaxial with the center conductor and located between the center conductor and the outer shield conductor. The inner shield conductor has a resistance adapted to control resonance on the inner shield.
A zero-crossing detector includes a pair of input terminals, the terminals being adapted to receive an AC input signal; a rectifier, the rectifier rectifying the AC input signal; a current source, the current source being powered by the rectified AC input signal; and an optoelectric coupler having a coupler input and a coupler output, the coupler input being driven by the current source and the coupler output providing a zero-crossing signal. The zero-crossing signal is galvanicly isolated from the AC input signal.
H03K 5/153 - Arrangements in which a pulse is delivered at the instant when a predetermined characteristic of an input signal is present or at a fixed time interval after this instant
A solid state switch includes a solid state device having an input terminal, an output terminal and a gate terminal; a quick response circuit selectively operable to initially place the solid state device in a conducting state; and a sustained response circuit selectively operable to maintain the solid state device in the conductive state after the quick response circuit. The input terminal and the output terminal are connected when the solid state device is in the conducting state and the input and the output terminal are disconnected when the solid state device is not in the conducting state.
A test instrument network for testing a plurality of DUTs includes a plurality of communicating script processors, the script processors being adapted to execute computer code; and a plurality of measurement resources controllable by the script processors in response to executed computer code, the measurement resources being adapted to test the DUTs. Each script processor and measurement resource may be arbitrarily assigned by the controller to one of at least two groups, only one script processor being assigned to be a master script processor, any other script processor being a slave script processor and any group not including the master script processor being a remote group. The master script processor is exclusively authorized to initiate code execution on any script processor in a remote group. Any slave script processor is only able to initiate operation of measurement resources in it own group. When a particular script processor is executing computer code, the master script processor may not initiate execution of computer code on a member script processor in the group of the particular script processor and may not initiate operation of a member measurement resource in the group of the particular script processor.
G05B 17/00 - Systems involving the use of models or simulators of said systems
G06F 19/00 - Digital computing or data processing equipment or methods, specially adapted for specific applications (specially adapted for specific functions G06F 17/00;data processing systems or methods specially adapted for administrative, commercial, financial, managerial, supervisory or forecasting purposes G06Q;healthcare informatics G16H)
G06F 9/00 - Arrangements for program control, e.g. control units
A method for operating a DAC to minimize digital feedthrough includes inputting a clock signal to a DAC clock input, the clock signal having a periodic series of trigger events, wherein input data must be present for a time window between a setup time before a trigger event and a hold time after the trigger event; generating an input data stream, the input data stream having data that is present for the time window; altering the input data stream into a cancellation data stream wherein the data presence is maintained but pseudo-data outside of the time window is added; and applying the cancellation data stream to a DAC data input resulting in an analog signal output.
A method for measuring electrical parameters of a DUT having at least three terminals includes applying a first AC voltage to a first terminal; separately driving a second and a third terminal each to a virtual second AC voltage, each virtual voltage requiring a respective current; and measuring an electrical parameter of the DUT based on the first AC voltage and the second and third terminals each being at the virtual second AC voltage.
The errors related to the resistance of test conductors and sense/load resistances for a pulse I-V measurement system are determined by making open circuit and through circuit measurements using a combination of DC and pulse instrument measurements.
A guarded sense impedance for use in a measurement instrument includes a sense impedance adapted to have a spatially distributed electrical potential and at least one guard structure adapted to have the spatially distributed electrical potential. The guard structure is arranged to provide a spatially distributed guard potential for the sense impedance.
G01R 27/26 - Measuring inductance or capacitanceMeasuring quality factor, e.g. by using the resonance methodMeasuring loss factorMeasuring dielectric constants
G01F 23/00 - Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
44.
Test system connection system with triaxial cables
A connection system for connecting test equipment to a device under test (DUT) includes a first pair of equal-length triaxial cables, each having a desired characteristic impedance between a center conductor and an outer conductor, the outer conductor of each first cable being connected to each other at respective proximal and distal ends of the first cables, the distal end of each first cable center conductor being connected to each other, and the distal end of each of a first cable intermediate conductor being connected to each other; and a second pair of equal-length triaxial cables, each having the desired characteristic impedance between a center conductor and an outer conductor, the outer conductor of each second cable being connected to each other at respective proximal and distal ends of the second cables as well as to the respective proximal and distal ends of the outer conductors of the first cables, the distal end of each second cable center conductor being connected to each other, and the distal end of each of a second cable intermediate conductor being connected to each other, wherein four-wire measurements are made using each of the triaxial cables individually and two-wire measurements are made using each pair of cables in parallel thereby providing a characteristic impedance equal to the desired characteristic impedance, the DUT being locatable at the distal end of the cables.
A bias tee for connecting a measurement device to a DUT, where the measurement device has a guard output, includes a DC port; a HF port; and a measurement port. The HF input port is guarded with the guard output during operation of the bias tee.
G01R 27/26 - Measuring inductance or capacitanceMeasuring quality factor, e.g. by using the resonance methodMeasuring loss factorMeasuring dielectric constants
09 - Scientific and electric apparatus and instruments
18 - Leather and imitations of leather
Goods & Services
Signal analyzers; apparatus and instruments for measuring, testing, and calibration; signal generators, signal dividers; amplifiers, relays; oscilloscopes, multimeters, digital multimeters, voltmeters, static meters, ammeters, ohmmeters, electrometers, thermometers, timers, counters; semi-conductor parametric testers; pulse and pattern generators; battery packs, cables, mount kits, leads, and probes; electrical sources and electrical power supplies; electrical circuit assemblies; electrical bridges and accessories; switching systems; electrical switching apparatus; electrical cables, connectors and interfaces; computers; computer programs and computer software, apparatus for use with computers; interfaces; data recording apparatus; data processor cards and boards; data acquisition modules, cards and boards; terminal boards; parts and fittings for all of the aforesaid goods. Bags and carrying cases.
09 - Scientific and electric apparatus and instruments
10 - Medical apparatus and instruments
Goods & Services
(1) Measuring and scientific apparatus comprising electrical and electronic apparatus namely, signal dividers, amplifiers, voltage supplies, relays, and measuring instruments namely, ammeters, voltmeters, ohmmeters, electrometers, static meters, and electrical bridges and accessories thereof.
