DE102022128841A1 - FLEXIBLE WIDE BAND GAP DOUBLE PULSE TEST METHODOLOGY - Google Patents

Abstract

A test and measurement instrument has a user interface, one or more probes to connect the instrument to a device under test (DUT), and one or more processors configured to execute code to execute the one or more to cause processors to: receive one or more user inputs via the user interface, at least one of the user inputs being used to determine at least one analysis to be performed on the DUT, receiving waveform data from the DUT when the DUT by applying activated by power from a power supply, and applying a first or second pulse or multiple pulses from a source instrument, performing the at least one analysis on the waveform data, and displaying the waveform data and the analysis on the user interface. A method for automatically performing a double-pulse test and analysis on a device under test (DUT) includes receiving user input via a user interface on a test and measurement instrument, wherein the user input is used to designate at least one analysis to be performed by the DUT received waveform data is to be performed, receiving the waveform data from the DUT when the DUT is activated by applying power from a power supply, and applying a first or a second pulse or multiple pulses from a source instrument, performing analysis of the waveform data, and displaying the waveform data and analysis on the user interface.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This disclosure claims priority to Indian Provisional Application No. 202121050042 entitled Automated Double Pulse Test (DPT) Measurements with Reverse Recovery Plot for System Validation of Wide Brand Gap (WBG) Power Devices During In-Circuit Operation, filed on 01.01 November 2022, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL AREA

The present disclosure relates to the testing and measurement of semiconductor-based power devices.

BACKGROUND

Semiconductor materials used in power electronics are migrating from silicon to wide band gap (WBG) semiconductors such as silicon carbide (SiC) and gallium nitride (GaN) due to their superiority at higher power levels in automotive and industrial applications.

GaN and SiC technologies enable smaller, faster and more efficient designs. Full verification of a SiC or GaN based WBG device requires both static and dynamic measurements. The preferred test method for measuring the switching and diode blocking parameters of MOSFETs or IGBTs is commonly performed using the Double Pulse Test (DPT) method.

Verification of a WBG system is accomplished by comparing real-time waveforms during DPT experiments over a range of operating conditions for a wide range of voltage and thermal values.

DPT is a clearly defined procedure for measuring switching parameters and evaluating the dynamic behavior of power components.

The IEC and JEDEC standards define the dynamic testing of WBG power components. DPT helps determine key switching device performance parameters through the following measurements: switching parameters, diode reverse recovery energy and time, gate charge, and capacitance analysis.

Customers perform in-circuit operation of the DUT board without external stimulus and characterize the discrete MOSFET/IGBT components early in the workflow. In-circuit testing reflects the real-world scenario of DUT operation and is sometimes referred to as system verification. There are no standard measurements or testing procedure for testing the DUT in the system verification phase.

With traditional DPT setups, manually performing these tests under different permutations of test parameters and then manually analyzing the experimental data is a time-consuming and error-prone process.

Currently, customers are testing the WBG devices by manually saving the waveforms, exporting them to tools such as Excel or LabVIEW; using their own techniques and documenting the test reports; as well as iterate over multiple DUTs (10 to 20). Project delays also result in delayed time to market and the loss of key customers to competitors.

One of the biggest challenges customers face when system verifying WBG reference designs is how to improve verification times. It takes longer to capture real-time waveforms and analyze them across multiple sweeps. A few days are required to check and test just one single power component. The main features are taking multiple measurements, testing multiple DUTs; manual review, analysis and reporting, causing delays.

Another key challenge is the lack of confidence in test results. A DPT test requires automated measurements and control of instruments such as AFG, DUT board and measurement system (oscilloscope) during dynamic testing, as test engineers use their own code or tools for analysis, resulting in ineffective control of test setups and probes do not meet bandwidth, dynamic range, and common-mode rejection ratio requirements, and oscilloscopes must have multiple channels, equalization capability, and high dynamic range.

A do-it-yourself solution is dominant in this area and consists of custom builds that differ from one company to the next. Even if the measurements side is covered quite well, from the system point of view there is no standard because technology and Implementation may vary from company to company and from build to build. This leads to low confidence in the test setup and poses a challenge in terms of correlating the results. There is no standardized and accepted solution for verifying in-circuit operation of a DUT.

Existing test procedures from T&M vendors do not provide a dedicated oscilloscope-based solution for system verification. Therefore, there is a need for an efficient inspection solution.

character list

• 1 shows a circuit diagram of parasitic elements in DPT power circuits.
• 2 shows a schematic flow chart of the sequence of a circuit board check.
• 3 Figure 12 shows an embodiment of a schematic flowchart of the workflow.
• 4 Figure 12 shows one embodiment of a measurement array of DPT flow.
• 5 FIG. 12 shows an embodiment of a schematic circuit diagram showing test points for measuring switching parameters.
• 6 12 shows one embodiment of turn-on-turn-off transitions in an insulated gate bipolar transistor (IGBT).
• 7 Figure 12 shows an image of an E _on configuration and a results plaque for one embodiment of a WBG-DPT solution.
• 8th Figure 12 shows an annotated E _on range using one embodiment of a WBG solution on an oscilloscope with navigation.
• 9 14 shows an image of reverse current captured on an oscilloscope using Tektronix current probes (TCP) in one embodiment of a reverse recovery process.
• 10 Figure 12 shows one embodiment of a schematic circuit diagram showing test points for measuring diode reverse recovery.
• 11 Figure 12 shows a lock recovery time (Trr) configuration page and measurement plaque for one embodiment of a WBG-DPT solution.
• 12 Figure 12 shows a lock recovery region annotated on a waveform using one embodiment of a WBG-DPT solution.
• 13 Figure 12 shows one embodiment of a recovery charge area, enlarged and labeled.
• 14 Figure 12 shows one embodiment of a superimposed reverse recovery plot for multi-pulse.
• 15 Figure 12 shows one embodiment of a superimposed regenerative charge region for multiple pulses on a reverse recovery plot.
• 16 Figure 12 shows a single reverse recovery plot and its associated waveform of one embodiment of performing a reverse recovery test.
• 17 Figure 12 shows several reverse recovery plots, the corresponding waveform and reverse recovery current resulting from one embodiment of performing a reverse recovery test.

DETAILED DESCRIPTION

The various embodiments of the present disclosure provide automated double pulse test (DPT) measurements with a reverse recovery diagram for system verification of wide band gap (WBG) power devices during in-circuit operation.

Measurement of reverse recovery characteristics is highly dependent on detection accuracy. With industry-leading probes developed by Tektronix, such as the Iso-Vu probes and the Tektronix current probes (TCP), systems can measure reverse recovery characteristics close to the actual characteristics of the device. The embodiments presented here have several advantages. This includes defining a workflow to follow and troubleshooting new designs in accordance with industry standards. Other benefits include automated measurements with verification and feedback, automation of the source instrument, test and measurement instrument, and device under test (DUT), and flexibility with customer-specified reference values and configurable measurement integration points. Other benefits include a new chart type for plotting lock recovery with the ability to overlap time slices, per-cycle analysis with annotations, and control of single and multi-pulse results and statistics.

The embodiment solution based on a WBG test and measurement instrument provides workflow flexibility and performs complex measurements. These standards include: including the standards set by various standardization bodies such as JEDEC (Joint Electronic Device Engineering Council) and IEC (International Electrotechnical Commission). This solution (WBG-DPT) is very useful for developers and review teams.

Power electronic systems involve switching power semiconductor devices (PSDs) by applying control signals to control the flow of current. The dynamic behavior of PSDs has a significant impact on the efficiency and power density of power converters and other power electronic systems.

1 Figure 12 shows the two primary parasitic circuits in a DPT power stage, a power circuit 10 and a control circuit 12. _LS and _LD are stray inductors in the main power circuit. L _G is the parasitic inductance associated with the gate circuit. Parasitic capacitances in the MOSFET, C _GS , C _GD and _CDS contribute to slower switching and increase switching losses. L _D and L _G are the main contributors to parasitic overshoot, but the overshoot is more sensitive to L _D due to fast switching. As a result, system verification through in-circuit testing is critical for designers, otherwise the PCB effects will be overlooked during characterization.

The DUT is customized based on target applications. The circuit board is designed to be compact and minimize the effects of the parasitic circuit and its circuitry affecting the dynamic performance of the packaged circuit board. The fast-switching WBGs are very sensitive to the parasitic circuitry, making it critical to measure DPT switch and diode recovery parameters during in-circuit operation as part of system verification. The information gained from the DPT analysis helps in predicting the thermoelectric behavior of the board, which is very valuable for verifying target application designs.

2 Figure 12 shows one embodiment of a workflow of reviewing reference designs through to the final product. The device under test (DUT) has discrete components integrated into the test circuitry with test points provided. The system is typically started up by applying power from a power supply. The test software sets the pulse or pulses to be applied to the DUT. A source instrument such as B. an arbitrary waveform generator (AFG) or other waveform source can be used. The DUT then undergoes testing and analysis to ensure that it meets the desired results and/or standards. The analysis of the results and any post-processing then complete the test.

3 12 shows a workflow using the embodiments. The embodiments provide an automated process with minimal user intervention. The packaged distinctive components 20 are mounted on the integrated circuit board/PCB 22 . The power supply 24 turns on to provide power and the source instrument 28, e.g. B. an AFG, provides the pulses used for the test. The test and measurement instrument 26 supports the extraction of the parasitic components, the inductance and the S-parameter file and has complete measurement sets according to industry standards.

Note that the discussion focuses on an AFG as the source instrument and an oscilloscope as the test and measurement instrument, but this discussion uses these for clarity and is not intended in any way to limit these items to these specific examples.

The embodiments presented here enable a large number of measurements for WBG devices. 4 shows a user interface showing a grouping of such measurements. As can be seen, in this embodiment, the user interface presented by the test and measurement interface allows for the selection of the device type, either a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or an Insulated Gate Bipolar Transistor (IGBT), both examples of wide bandgap devices . The test and measurement instrument supports multiple power devices, including but not limited to silicon carbide (SiC) and gallium nitride (GaN) MOSFETs, silicon devices, and GaN HEMT (High Electron Mobility Transistor) devices. The user can select the voltage and current source channels as well as the gate voltage channel. The user can also choose from a variety of tests using the test setup. This includes, for example, the analysis of switching parameters, the analysis of the switching time, the analysis of the diode reverse recovery and the capacitance analysis.

5 12 shows an embodiment of a scenario for measuring switching parameters. The semiconductor DUT is on the low-side position (Q2) and forms together with a freewheeling diode (FWD) in a high-side position (Q1) the switching cell to be tested.

Probes of test and measurement instrument 28 sense the switching voltage and current and the gate voltage of Q2. The configuration of the probe connections on the test and measurement instrument 26 is merely an example. The probes are connected to the test and measurement instrument via ports 32 which in turn transmit data to the processor 30 . The user interface 34, on which the menu like that in 4 shown, allows the user to interact with the testing process. The user interface here includes a touchscreen embodiment, but could also include any combination of a display and controls such as knobs or buttons. The processor may include one or more processors that execute code to cause the one or more processors to perform the methods of the embodiments.

As can be seen in the diagram, there is an optional connection between the source instrument and the test and measurement instrument. Activating the DUT as used here means applying current from the power supplies and then applying pulses from the source instrument. The application of the source instrument can be synchronized with the test and measurement instrument via the optional connection/communication channel.

This system allows for the automation of the DPT process, but still allows for variations. For example, the system can automatically set the pulse range for the second pulse according to one of many industry standards. However, the user has the flexibility to change the pulse range based on their DUT operation. If "automatic" is selected, the user does not have to make any settings in the measurement configuration. The automatic adjustment performs both verification and measurement of the waveform.

In the user-selectable settings, where 7 shows an embodiment of a menu for these, the measurement may fail if the user fails to enter the second pulse range. In this case, the measurement fails and the user receives feedback in the result plaque. For example, if the second pulse region is not present, the user is notified with, for example, 'No valid E _on region present on second pulse...'.

Taking an IGBT as an example, one can calculate the turn-on and turn-off parameters by looking at the falling edge of the first pulse and the rising edge of the second pulse, as in 6 shown. An analysis of the switching parameters measures the energy dissipated in the IGBT during turn-on of a single collector current pulse, described in the following equation: $${\text{E}}_{\text{on}}={\displaystyle {\int }_{\text{sound start}}^{\text{sound stop}}{\text{V}}_{\text{CE}}}{\text{I}}_{\text{C}}\text{German}$$

Energy lost in the IGBT during the turn-off time plus the follow-up time of a single collector current pulse. $${\text{E}}_{\text{off}}={\displaystyle {\int }_{\text{Toffstart}}^{\text{Toffstop}}{\text{V}}_{\text{CE}}}{\text{I}}_{\text{C}}\text{German}$$

8th Figure 12 shows one embodiment of a resulting waveform with an E _on region annotated, and the user can scroll and zoom through the waveform to see details of the displayed waveform data.

The one or more processors in the test and measurement instrument provide the ability to increase the accuracy of the measurements by performing signal conditioning on the incoming waveform data. The data coming in from the DUT is usually analog signal data that undergoes analog-to-digital conversion prior to analysis. Signal conditioning can include voltage or current limiting, application of anti-aliasing filters, amplification, filtering and much more. Signal conditioning typically mitigates the effects of noise to ensure measurements are more accurate than they would be without signal conditioning. Other noise control techniques may include the use of a hysteresis band loop or a filter.

Although the above discussion mentions user input identifying the analysis to be performed by the DUT as user input, user input could also consist of a user providing an automated script or other form of programming through a programmatic interface to carry out the examination and analysis in an automated manner. This applies to all aspects of the DPT exam, including lock recovery discussed below.

During the beginning of the second pulse of the double pulse test, the freewheeling diode, which is in forward mode, switches to reverse mode. The current in the diode drops to below zero and then recovers to 0 amps as in 9 shown. The time it takes for the system to get back to 0 amps is called the reverse recovery time (T _rr ), and the reverse recovery time and the resulting recovery charge (Q _rr ) exhibit some of the important properties of the reverse biased system that it needs to be analyzed. The embodiments allow the user to perform the T _rr measurement with a single current waveform or use the gate-source voltage as an edge qualifier. 10 shows an embodiment of a test setup.

The lock recovery time can be calculated using the following formula: $$T\mathrm{right}\mathrm{right}=ta+tb$$

Where t _a is the time it takes during the second pulse for the reverse current to decrease from 0 amps to reaching the maximum reverse current and t _b is the time at which an extrapolated tangent drawn on the reverse current ramps towards 0 ampere is placed, the zero current axis intersects.

After the user provides the appropriate inputs for the measurement, t _a is determined using a robust edge detection technique on the waveform where the edge at zero amperes is within a hysteresis band. A tangent line is drawn for t _b to analyze the reverse time as the reverse current recovers from its maximum reverse current to the zero current axis. In some standards, this tangent should pass through the 90% and 25% points of the maximum reverse current (I _rm ). For a novice user, the solution provides automatic levels configured by the oscilloscope according to industry standards.

Since current recovery can be very abrupt or gentle depending on the system, the ability to configure these percentage levels is of great value. In the embodiment of the WBG solution, the user can configure this tangent line to pass through different starting and ending percentages of I _rm . The straight line equation that runs through A% and B% of I _rm at time t ₁ and t ₂ respectively is determined as follows: $$I\left(t\right)=\frac{I\mathrm{right}m\ast \left(\frac{B-A}{100}\right)}{\left(\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="DE102022128841A1\_0014.png,DE102022128841A1\_0016.png"\; state="\{\{state\}\}">t</figure-callout>}2-t1\right)}t+\frac{\left(\frac{\left(\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="DE102022128841A1\_0014.png,DE102022128841A1\_0018.png"\; state="\{\{state\}\}">t</figure-callout>}1\ast B-\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="DE102022128841A1\_0014.png,DE102022128841A1\_0016.png"\; state="\{\{state\}\}">t</figure-callout>}2\ast A\right)}{100}\ast I\mathrm{right}m\right)}{\left(\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="DE102022128841A1\_0014.png,DE102022128841A1\_0018.png"\; state="\{\{state\}\}">t</figure-callout>}1-t2\right)}$$

The time when this tangent line intersects the zero current axis is at: $$tint=\left(\frac{\left(\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="DE102022128841A1\_0014.png,DE102022128841A1\_0018.png"\; state="\{\{state\}\}">t</figure-callout>}1\ast B-\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="DE102022128841A1\_0014.png,DE102022128841A1\_0016.png"\; state="\{\{state\}\}">t</figure-callout>}2\ast A\right)}{B-A}\right)$$

The reverse recovery time t _b is determined from this interruption time by subtracting the time at which the current has reached I _rm (t _rm ) from t _int . $$tb=tint-t\mathrm{right}m$$

As can be seen from equation 5, _tint is independent of I _rm . As the configuration of the start and end points of the tangent line varies, the overall lock recovery time (T _rr ) also varies. This novel configuration option provides a powerful tool for analyzing nonlinear lock recovery regions based on visual feedback and feedback from oscilloscope measurements. In the embodiments of a WBG solution presented here, the points through which the line is to pass can be specified as absolute values or as a percentage of I _rm . These configurations help engineers assess the nature of current recovery and quantify it with measurement results. 11 Figure 12 shows an embodiment of a user interface that allows a user to select the extrapolation values for the current for the first and second pulses if the user selects "custom" or to use the automatic values if the user selects "auto". 11 also shows the measurement plaque with the T _rr measurement.

In addition, because the lock recovery time parameters contain time-sensitive information, the proposed solution provides a new representation in the application called the lock recovery graph. 12 shows the captured waveform. The method zooms into the waveform by automatically finding the stop region and noting the relevant stop characteristic parameters as shown. The embodiments find the stopband on the captured waveform using the slope technique and measurement settings. After plotting the zoomed version of the waveform, the oscilloscope marks the region of interest with dashed lines and notes the appropriate lock recovery characteristics.

Traditional solutions are not able to automatically zoom into the lock recovery area and fill them with parameters like I _rm , the time to reach I _rm (t _a ), the intersection of the time axis with the tangent (t _b ), the total lock time (t _rr ) and other relevant parameters that decide the lock recovery time of the system.

The reverse recovery charge is an important parameter in determining the reverse blocking characteristics of the system. The recovery charge Q _rr can be approximated by the area under the reverse current versus time curve. This charge range represents the energy that must be dissipated at reverse voltage on the power switching side of the circuit. The user should provide a reverse current waveform as input to this measurement and has the option to provide the gate voltage as an edge qualifier as the gate source is usually cleaner because it comes directly from the IC.

Dabei ist t₀ die Zeit, zu der der Sperrstrom während des zweiten Impulses unter die Nullstromachse fällt, und t_i ist die Integrationszeit, bis zu der sich eine Sperrladung vorfindet.Q _rr is defined as the integral of the reverse current which, as in 13 shown flowing through the diode during a second pulse of the double pulse test: $$Q\mathrm{right}\mathrm{right}={\displaystyle {\int }_{t0}^{\mathrm{<figure-callout\; id="0"\; label="t"\; filenames="DE102022128841A1\_0012.png"\; state="\{\{state\}\}">t</figure-callout>}0+ti}i\mathrm{right}\mathrm{right}\times \mathrm{i.e}t}$$

Where t ₀ is the time at which the reverse current falls below the zero current axis during the second pulse, and t _i is the integration time up to which reverse charging is found.

The integration time to determine the reverse charge depends on I _rm . This integration time is found by sweeping the current waveform until the current reaches a specified percentage of I _rm during the current ramp up to the zero current axis. Some industry standards specify the latter percentage of I _rm to be 2% during recovery to the zero current axis.

Since each system design has its own tolerance to reverse charges, the solution offers the possibility to configure the integration time (t _i ) by specifying the percentage of the maximum reverse current (I _rm ). This novel configuration option provides for analysis of non-linear recovery zones. In the embodiments of the WBG solution, the I _rm value to integrate up to can be specified as an absolute value or as a percentage of I _rm . The new reverse recovery map for this measurement determines the reverse recovery region from the acquired waveform, notes the time taken into account for integration in Equation (7), and fills in the total charge region.

A unique approach of the new lock recovery graph is its ability to account for multiple sets of double pulses and provide visual and measurement results for each set. The user can configure measurements in the WBG solution to request results for each first pulse, second pulse, or for all pulses of the double pulse set. If there are multiple pulses, the edge qualifier waveform provided for the measurement is used as a reference to determine the pulse position. 14 shows an example of displaying multiple lock recovery graphs and multiple lock recovery regions. It should be noted that while the plots show only one impulse 1 and one impulse 2 as noted in the legend, there can be up to N impulses. A measurement plaque or legend shows the current impulse results along with the average results of all impulses. In the lock recovery chart of 14 is the time range given for the current noted range, for impulse 1 the solid line. 15 shows several plots with a lock recovery area.

16 and 17 show embodiments of diagrams with their corresponding waveforms and reverse recovery current. 16 shows a single representation and 17 shows several representations.

The embodiments of the WBG application display multiple pulses in a single plot, with the reverse current (I _rr ) recovery region displayed along with other recovery regions in the background for comparison. Because there are multiple regions of interest in an acquisition, the instrument uses a single current waveform to slice each region of interest and overlap them in the plot. The instrument is also capable of displaying multiple areas from multiple plots as an overlay, as in 17 shown. The multiple ranges can be from one signal acquisition or from multiple acquisitions.

The user interface allows the user to navigate through the waveform. In addition to zooming in on an area of interest, the user can filter the results by selecting the first pulse, the second pulse, each odd pulse, each even pulse, multiple pulses that are not odd or even, etc. Navigation enabled allows the user to go to the next, previous, minimum, maximum, etc. As the user navigates, the annotations are updated to reflect the zoomed area. Highlighting the zoomed area of interest may require using a different color, making the line bold, and so on. The instrument is also capable of analyzing the signals in both the forward direction (from left to right in the figures) and the backward direction (from right to left in the figures) to detect oscillations in the region of interest.

This new type of display in the oscilloscope enables the superimposition of several wave sections that change over time in a single waveform. This display also provides the ability to navigate through each of these areas and measurement results on the oscilloscope will update accordingly. There is currently no oscilloscope application on the market that can provide such a navigation capability for a single waveform with multiple stop regions that highlight stop features.

An additional extension of this lock recovery chart is the provision of configurable visual masking thresholds so that each lock region is below certain thresholds. The oscilloscope takes measurements and notifies you of every limit violation. This masking feature on the plot is helpful in maintaining a system's ideal reverse recovery range, which limits maximum recovery time, maximum reverse current, etc.

Aspects of the disclosure may operate on specially designed hardware, firmware, digital signal processors, or on a specially programmed general purpose computer having a processor operating according to programmed instructions. As used herein, the terms “controller” or “processor” are intended to include microprocessors, microcomputers, application specific integrated circuits (ASICs), and dedicated hardware controllers. One or more aspects of the disclosure may be embodied in computer-usable data and computer-executable instructions, such as one or more program modules, executed by one or more computers (including controller modules) or other devices. In general, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types when executed by a processor in a computer or other device. The computer-executable instructions may be stored on a non-transitory computer-readable medium such as a hard disk, optical disk, removable storage medium, solid-state memory, random access memory (RAM), and so on. As will be clear to those skilled in the art, the functionality of the program modules can be combined or distributed in various aspects as desired. Additionally, the functionality may be embodied in whole or in part in firmware or hardware equivalents such as integrated circuits, FPGA, and the like. Certain data structures can be used to more effectively implement one or more aspects of the disclosure, and such data structures are contemplated within the context of the computer-executable instructions and computer-usable data described herein.

The disclosed aspects may, in some cases, be implemented in hardware, firmware, software, or any combination thereof. The disclosed aspects may also be implemented in the form of instructions transmitted by or stored on one or more non-transitory computer-readable media that are readable and executable by one or more processors. Such instructions may be referred to as a computer program product. Computer-readable media, as described herein, is any media that can be accessed by a computing device. Computer-readable media can include, but is not limited to, computer storage media and communications media, for example.

Computer storage media is any media that can be used to store computer-readable information. Computer storage media may include, without limitation, RAM, ROM, electrically erasable programmable read only memory (EEPROM), flash memory or other storage technology, CD-ROM, DVD or other optical disk storage, magnetic cartridge, magnetic tape, magnetic disk storage or other magnetic storage device, or any others volatile or non-volatile, removable or non-removable media implemented in any technology. Computer storage media exclude signals per se and transient forms of signal transmission.

Communication media is any media that can be used for the transmission of computer-readable information. Communication media may include, but is not limited to, coaxial cable, fiber optic cable, air, or any other medium suitable for the transmission of electrical, optical, radio frequency (RF), infrared, acoustic, or other types of signals.

In addition, special features are referred to in this written statement. It should be clear that the disclosure in this specification encompasses all possible combinations of these special features. For example, if a specific feature is disclosed in relation to a particular aspect, that feature may also be used in relation to other aspects where possible.

Although this application refers to a method having two or more defined steps or acts, the defined steps or acts may be performed in any order or simultaneously unless the context precludes those possibilities.

EXAMPLES

The following are illustrative examples of the disclosed technologies. An embodiment of the technologies may include one or more and any combination of the examples described below.

Example 1 is a test and measurement instrument, comprising: a user interface; one or more probes for connection to a device under test (DUT); and one or more processors configured to execute code to cause the one or more processors to: receive one or more user inputs via the user interface, wherein at least one of the user inputs is to perform at least one analysis determine what is to be performed on the DUT; receiving waveform data from the DUT when the DUT is activated by applying power from a power supply and applying a first or second pulse or multiple pulses from a source instrument; performing the at least one analysis on the waveform data; and displaying the waveform data and analysis on the user interface.

Example 2 is the test and measurement instrument of Example 1, further comprising a communication channel between the test and measurement instrument and the source instrument, and wherein the one or more processors are further configured to execute code that executes the one or causing the multiple processors to synchronize the test and measurement instrument with the source instrument.

Example 3 is the test and measurement instrument of either of Examples 1 or 2, wherein the code that causes the one or more processors to receive the one or more user inputs comprises code that causes the one or more processors caused to receive the one or more user inputs to determine a switching parameter analysis, a switching time analysis, a diode reverse recovery analysis, or a capacitance analysis.

Example 4 is the test and measurement instrument of Example 3, wherein the user input determines a switching parameter analysis, and the one or more processors are further configured to display a set of user-selectable switching parameters for the analysis, the user-selectable Switching parameters include one or more of the following parameters: E _on , E _off , T _onLoss , T _offLoss , V _ce(peak) , I _c(peak) , V _ce(high) , I _c(high) , and switch summary measurement with statistics.

Example 5 is the test and measurement instrument of any of Examples 1-4, wherein the code that causes the one or more processors to receive one or more user inputs includes code that causes the one or more processors to do so to receive user input to indicate an automatic selection, and the one or more processors are further configured to automatically set a pulse range for the second pulse or a designation for the user to select a pulse range for the second pulse.

Example 6 is the test and measurement instrument of any of Examples 1 through 5, wherein the code that causes the one or more processors to display the waveform data and analysis on the user interface includes code that causes the one or more Causes processors to automatically mark an area of interest in the waveform data and display analysis data.

Example 7 is the test and measurement instrument of any of Examples 1-6, wherein the code that causes the one or more processors to perform the at least one analysis comprises code that causes the one or more processors to perform a perform energy loss analysis and notify a user of a failure, the failure being a missed second pulse.

Example 8 is the test and measurement instrument of any of Examples 1-7, wherein the one or more processors are further configured to execute code that causes the one or more processors to perform signal conditioning on the waveform data of of the DUT to mitigate noise effects and/or set a hysteresis band to compensate for noise in the waveform data.

Example 9 is the test and measurement instrument of any of Examples 1-8, wherein the one or more processors are further configured to execute code that executes the one or causing the multiple processors to select specific pulse areas in the waveform data for display and allowing a user to zoom and navigate to a specific area of the waveform data in response to user input, the one or more processors also including analysis data of the specific areas when the specific areas are displayed.

Example 10 is the test and measurement instrument of any of Examples 1-9, wherein the code that causes the one or more processors to receive one or more user inputs includes code that causes the one or more processors to do so to receive a user-selected source level, a user-selected voltage level, and/or a user-selected current level, the levels being either absolute or percentage levels.

Example 11 is the test and measurement instrument of any of Examples 1-10, wherein the code that causes the one or more processors to receive one or more user inputs includes code that causes the one or more processors to do so and receiving test parameters of a power device including a maximum voltage, a number of pulses, and/or a maximum current, and the one or more processors are further configured to execute code that causes the one or more processors to do so causes horizontal settings, vertical settings and trigger settings to be determined for maximum precision.

Example 12 is a method for automatically performing double-pulse testing and analysis on a device under test (DUT), comprising: receiving user input via a user interface on a test and measurement instrument, wherein the user input is used to determine at least one analysis to be performed on waveform data received from the DUT; receiving the waveform data from the DUT when the DUT is activated by applying power from a power supply and applying a first or a second pulse or multiple pulses from a source instrument; performing the analysis of the waveform data; and displaying the waveform data and analysis on the user interface.

Example 13 is the method of Example 12, further comprising synchronizing the test and measurement device with the source instrument.

Example 14 is the method of either of Examples 12 or 13, wherein receiving user input comprises receiving user input designating the analysis as a switching parameter analysis, switching timing analysis, diode reverse recovery analysis, or capacitance analysis.

Example 15 is the method of Example 14, wherein the user input determines a shift parameter analysis, and the method further comprises displaying a set of user-selectable shift parameters for analysis.

Example 16 is the method of any of Examples 12 to 15, wherein the user input includes either an automatic selection and the method further includes setting a pulse range for the second pulse, or a user selection in which a pulse range for the second pulse is selected.

Example 17 is the method of any of Examples 12-16, wherein displaying the waveform data and analysis on the user interface further comprises automatically annotating an area of interest in the waveform data and analysis display.

Example 18 is the method of any of Examples 12-17, wherein performing the analysis includes determining that the analysis failed and notifying the user of the failure.

Example 19 is the method of Example 18, where the analysis includes an energy loss analysis and the failure is that the second pulse is missing.

Example 20 is the method of any of Examples 12-19, further comprising allowing the user to select whether to perform the at least one analysis in a forward direction or a reverse direction.

Any feature disclosed in the specification, including the claims, the abstract and the drawings, and any step in a disclosed method or process may be combined in any combination, except for combinations where at least some of those features and/or steps are mutually exclusive exclude. Each feature disclosed in the specification, including the claims, abstract and drawings, may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Although certain embodiments have been shown and described for purposes of illustration, it should be understood that various changes can be made without departing from the spirit and scope of the disclosure. Accordingly, the invention should not be limited except as by the appended claims.

Claims (20)

Testing and measuring instrument, comprising: a user interface; one or more probes for connection to a device under test (DUT); and one or more processors configured to execute code to cause the one or more processors to: receiving one or more user inputs via the user interface, at least one of the user inputs to determine at least one analysis to be performed on the DUT; receiving waveform data from the DUT when the DUT is activated by applying power from a power supply and applying a first or second pulse or multiple pulses from a source instrument; performing the at least one analysis on the waveform data; and View the waveform data and analysis on the user interface. testing and measuring instrument claim 1 , further comprising a communication channel between the test and measurement instrument and the source instrument, and wherein the one or more processors are further configured to execute code that causes the one or more processors to load the test and measurement instrument synchronize with the source instrument. testing and measuring instrument claim 1 or 2 , wherein the code that causes the one or more processors to receive the one or more user inputs comprises code that causes the one or more processors to receive the one or more user inputs to perform a shift parameter analysis , a switching time analysis, a diode reverse recovery analysis or a capacitance analysis. testing and measuring instrument claim 3 , wherein the user input determines a switching parameter analysis, and the one or more processors are further configured to display a set of user-selectable switching parameters for analysis, the user-selectable switching parameters including one or more of the following parameters: E _on , E _off , T _onLoss , T _offLoss , V _ce(peak) , I _c(peak) , V _ce(high) , I _c(high) , and circuit overview measurement with statistics. Testing and measuring instrument according to one of Claims 1 until 4 , wherein the code that causes the one or more processors to receive one or more user input comprises code that causes the one or more processors to receive user input to indicate an automatic selection, and the one or the plurality of processors are further configured to automatically set a pulse range for the second pulse or a designation for the user to select a pulse range for the second pulse. Testing and measuring instrument according to one of Claims 1 until 5 , wherein the code that causes the one or more processors to display the waveform data and the analysis on the user interface comprises code that causes the one or more processors to automatically annotate an area of interest in the waveform data, and display analysis data. Testing and measuring instrument according to one of Claims 1 until 6 , wherein the code that causes the one or more processors to perform the at least one analysis comprises code that causes the one or more processors to perform a power loss analysis and notify a user of a failure, the failure in a missing second pulse. Testing and measuring instrument according to one of Claims 1 until 7 , wherein the one or more processors are further configured to execute code that causes the one or more processors to apply signal conditioning to the waveform data from the DUT to mitigate noise effects and/or to adjust a hysteresis band, to smooth out noise in the waveform data. Testing and measuring instrument according to one of Claims 1 until 8th , wherein the one or more processors are further configured to execute code that causes the one or more processors to select particular pulse regions in the waveform data for display and allow a user, in response to user input to a zoom and navigate to a specific area of the waveform data and to multiple areas, wherein the one or more processors also display analysis data of the specific areas when the specific areas are displayed. Testing and measuring instrument according to one of Claims 1 until 9 , wherein the code that causes the one or more processors to receive one or more user inputs comprises code that causes the one or more processors to receive a user-selected source level, a user-selected voltage level, and/or receive a user-selected power level, the levels being either absolute or percentage levels. Testing and measuring instrument according to one of Claims 1 until 10 , wherein code that causes the one or more processors to receive one or more user inputs comprises code that causes the one or more processors to receive test parameters of a power device that include a maximum voltage, a number of pulses and/or a maximum current, and the one or more processors are further configured to execute code that causes the one or more processors to determine horizontal adjustments, vertical adjustments, and trigger adjustments for maximum precision. A method for automatically performing a double pulse test and analysis on a device under test (DUT), comprising: receiving user input via a user interface at a test and measurement instrument, the user input to designate at least one analysis to be performed on waveform data received from the DUT; receiving the waveform data from the DUT when the DUT is activated by applying power from a power supply and applying a first or a second pulse or multiple pulses from a source instrument; performing the analysis of the waveform data; and View the waveform data and analysis on the user interface. procedure after claim 12 , further comprising synchronizing the test and measurement instrument with the source instrument. procedure after claim 12 or 13 , wherein receiving a user input comprises receiving a user input designating the analysis as a switching parameter analysis, a switching timing analysis, a diode reverse recovery analysis, or a capacitance analysis. procedure after Claim 14 wherein the user input determines a shift parameter analysis, and the method further comprises displaying a set of user selectable shift parameters for analysis. Procedure according to one of Claims 12 until 15 wherein the user input comprises either an automatic selection and the method further comprises setting a pulse range for the second pulse, or a user selection selecting a pulse range for the second pulse. Procedure according to one of Claims 12 until 16 wherein displaying the waveform data and analysis on the user interface further comprises automatically annotating an area of interest in the waveform data and analysis display. Procedure according to one of Claims 12 until 17 , wherein performing the analysis comprises determining that the analysis has failed and notifying the user of the failure. procedure after Claim 18 , where the analysis involves an energy loss analysis and the failure is that the second pulse is missing. Procedure according to one of Claims 12 until 19 , further comprising allowing the user to select whether to perform the at least one analysis in a forward direction or in a reverse direction.

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