Teledyne LeCroy provides the most confidence for testing every power device — from low-voltage (60 V) GaN power MOSFETs to any type of GaN transistor used in 500 V applications (FETs or HEMTs) to Si and SiC MOSFETs and IGBTs commonly used at voltages of 1000 V (or more).
Teledyne LeCroy has the solutions you need for testing GaN and SiC MOSFETs, whether that is a MOSFET in a double-pulse test circuit, measuring switching performance in an inverter subsection, or testing complete system operation.
The double pulse test procedure is used for evaluating the in-circuit dynamic behavior of power semiconductors. Double pulse testing uses gate-drive signals to stress the DUT and measure energy loss during device turn-on/turn-off, as well as measuring reverse recovery of the diode.
Teledyne LeCroy’s DPT-AUTOMATION software provides the most double pulse test automation at the most affordable price.
Typical differential probes operate with differential and common-mode ratings of ~24 V maximum (sometimes up to 42 V). High voltage differential probes don't have enough bandwidth, may not have enough accuracy at lower voltages, and may have too much tip capacitance. Optical isolated HV probes are costly and have unnecessary isolation performance. Optimized probes are needed – Teledyne LeCroy has them.
60 V GaN designs must have high efficiency to maximize battery life. To maximize efficiency, 60 V GaN MOSFETs use rise times as fast as 1 ns. Lower-cost, high performance probes are needed to measure all signals — gate-drives, device outputs, DC voltages and system outputs.
Optical probes are too expensive and/or have too much performance for the lower dV/dT and common-modes present in 60 V designs. High voltage differential probes are not performance optimized for this application. Only one differential probe – the Teledyne LeCroy DL-HCM Series – is optimized for 60 V GaN probing.
DL-HCM series probes have the high performance required to faithfully measure your high-speed gate-drive and device output signals.
Measure every in-circuit signal, regardless of where it is in your circuit, with switchable attenuation for higher voltages.
System output measurement often don’t require high bandwidth, but still require high accuracy, low noise, and good noise immunity (high probe CMRR). If probe pricing is a challenge, HVD Series probes can balance price and performance for some GaN system measurements.
Teledyne LeCroy High Definition Oscilloscopes (HDO®) provide 12 bits of resolution all the time at full oscilloscope bandwidth ratings. Once you use a Teledyne LeCroy HDO, you’ll never want to go back to using another oscilloscope.
Teledyne LeCroy oscilloscopes and software application packages provide faster and more complete debug of half-bridge, full-bridge and cascaded H-bridge inverter subsections and systems.
Fast rise times combined with high switching voltages make it difficult to make interference-free measurements. Confidence is needed in the signal acquisition to ensure that measured signals accurately portray the signals in the circuit.
The high dV/dt and voltage ratings of 650 V GaN MOSFETs implemented in 500 Vdc designs require specialized optical probes, high-quality high voltage differential probes, and high-resolution, low-noise oscilloscopes.
Optical isolation provides the best noise immunity at the fastest dV/dt while also providing safe operation, high signal fidelity and the easiest connections to in-circuit signals in compact GaN designs.
Optical isolation provides the best noise immunity at the fastest dV/dt while also providing safe operation, high signal fidelity and the easiest connections to in-circuit signals in compact GaN designs.
HVD3000A series differential probes provide high CMRR over a broad frequency range to simplify the measurement challenges found in noisy, high common-mode power electronics environments. The probe’s design is easy-to-use and enables safe, precise high voltage floating measurements.
Teledyne LeCroy High Definition Oscilloscopes (HDO®) provide 12 bits of resolution all the time at full oscilloscope bandwidth ratings. Once you use a Teledyne LeCroy HDO, you'll never want to go back to using another oscilloscope.
Teledyne LeCroy oscilloscopes and software application packages provide faster and more complete debug of half-bridge, full-bridge and cascaded H-bridge inverter subsections and systems.
SiC MOSFET devices are commonly used at higher switching voltages and currents and share many characteristics with well-known silicon devices. SiC devices are increasingly deployed in 800 V traction inverters and next-generation utility transmission and distribution system power conversion designs.
SiC MOSFETs with ratings of 1200 V, 1700 V and 3300 V are employed in cascaded H-bridge and multi-level cascaded H-bridge designs to achieve very high operating voltages at high power levels. High-performance, robust probes are needed to measure the wide range of signals found in these designs.
Optical isolation provides the best noise immunity at the fastest dV/dt while also providing safe operation, high signal fidelity and square header connections to in-circuit signals in SiC designs
The Teledyne LeCroy HVD3605A high voltage differential probe is the only HV differential probe worth considering for >1500 V SiC measurements and combines exceptional noise immunity with high performance.
Utility grid-tied solar photovoltaic (PV) inverters, uninterruptible power supplies (UPS) and welding systems commonly use 1500 Vdc buses to minimize system cost. Teledyne LeCroy’s HVD3206A or HVD3220 are ideal for this application.
Teledyne LeCroy High Definition Oscilloscopes (HDO®) provide 12 bits of resolution all the time at full oscilloscope bandwidth ratings. Once you use a Teledyne LeCroy HDO, you'll never want to go back to using another oscilloscope.
Teledyne LeCroy oscilloscopes and software application packages provide faster and more complete debug of cascaded H-bridge and multi-level cascaded H-bridge inverter subsections and systems.
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Comparing High Resolution Oscilloscope Design Approaches
This white paper provides an overview of the various high resolution design approaches, with examples of their impact on oscilloscope performance. |
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How to Choose the Best High Voltage Oscilloscope Probe in 5 Minutes Need to select a high-voltage oscilloscope probe? Confused by all the possible choices? Teledyne LeCroy offers the High-voltage Probe Selection Guide, an online tool to help you make an informed decision. Here's a breakdown of the basic points to consider. |
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Recommended Equipment List for Double Pulse Testing Recommended Teledyne LeCroy test equipment for performing double pulse testing on 60 V GaN, 650 V GaN/SiC and 1000 V (or higher) SiC, complete with URL links. |
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Join Teledyne LeCroy for a practical, application-focused session featuring a live demonstration on a GaN MOSFET.
In this webinar attendees will learn how to perform the double pulse test safely, and capture and characterize a GaN or SiC power semiconductor device’s dynamic response.
In Part 2 of our Oscilloscope Coffee Break Webinar Series we explain deskewing to eliminate timing errors. Propagation delay differences between your probes and/or channels may affect timing measurement accuracy. Methods to minimize these errors will be described.
Power electronics designs have inherent measurement challenges. Proper probe selection and use is critical for operator, equipment and DUT safety and also has a large influence on the accuracy of the measurement.
In this webinar we describe new products and best practices and measurement techniques for validation and debug of 48 V power conversion systems.
Choosing and using a Bench PSU: What to consider when purchasing a bench PSU: linear verse switch mode, total power, number of outputs, programmable, etc. Using a bench power supply: Know the tips and tricks for getting the most from your bench power supply: parallel and serial output configurations, 4 wire connections, using multiple power supplies on a single DUT, etc.
There has been an explosion in the market of high definition oscilloscopes at 1 GHz or more bandwidth with claims of 10-bit, 12-bit or even (remarkably!) 16-bit resolution. Oscilloscope manufacturers use a variety of design approaches to increase resolution, some of which impose other performance tradeoffs. Join Teledyne LeCroy for this two-part webinar series to gain a better understanding of various manufacturer’s claims.
Register for allOscilloscope manufacturers use a variety of design approaches to increase resolution, some of which impose other performance tradeoffs. Join Ken Johnson for this two-part webinar series to gain a better understanding of various manufacturer’s claims.
Oscilloscope manufacturers use a variety of design approaches to increase resolution, some of which impose other performance tradeoffs. Join Ken Johnson for this two-part webinar series to gain a better understanding of various manufacturer’s claims.
Join Teledyne LeCroy for this Learning Lab series on measuring high-power, three-phase and motor inverter and drive systems with an 8-channel high-resolution oscilloscope or motor drive analyzer.
Register for allIn Part 1 of our 3-phase Power and Motors Masters Webinar Series we describe techniques for measuring dead-times for gate-drive signals and device outputs to ensure that margins are achieved.
In Part 2 of our 3-phase Power and Motors Masters Webinar Series we describe the differences between static and dynamic power analysis and how to optimize setup and measurement for each.
In Part 3 of our 3-phase Power and Motors Masters Webinar Series we review examples of using calculated per-cycle power waveforms to validate and debug control system operation to power section behaviors.
In Part 4 of our 3-phase Power and Motors Masters Webinar Series we review examples of power calculated during power periods equivalent to a device switching time.
In Part 5 of our 3-phase Power and Motors Masters Webinar Series we demonstrate how to perform total harmonic distortion (THD) and harmonic analysis on variable frequency waveforms on both AC line (50 or 60 Hz) inputs and variable frequency outputs.
In Part 6 of our 3-phase Power and Motors Masters Webinar Series we focus on how to use the Motor Drive Analyzer (MDA) to measure motor mechanical shaft speed, torque and angle using a variety of analog, digital and serial data sensors.
This link www.teledynelecroy.com/wide-bandgap#double-pulse-test has complete details. In summary, a half-bridge circuit is typically used, and is built with a switchable inductor at the mid-point of the half-bridge. A simulated gate-drive pulse is applied to either the low or high-side device and various measurements are made using appropriate isolated probes and oscilloscopes.
A single-ended probe has a ground that effectively connects the oscilloscope ground and the device-under-test (DUT) reference ground. If the DUT reference ground cannot be at oscilloscope (earth) ground, then an isolated probe is needed for any measurement in a power conversion system in which the DUT reference is floating above earth ground. Optical isolation is expensive but provides superior performance, especially at higher floating voltages and higher switching voltages where EMI can interfere more with the performance of conventional (lower CMRR) electrically isolated probes.
The Teledyne LeCroy DL-ISO is a newer, higher bandwidth probe that is optimized for both small signal (e.g., gate-drive) measurements and higher voltage (device output) measurements. The DL-ISO is ideal for both GaN and SiC. The Teledyne LeCroy HVFO has lower bandwidth (consistent with Silicon and perhaps Silicon-carbide rise times) and is only optimized for small-signal measurements, but costs much less than the DL-ISO. This link https://www.teledynelecroy.com/probes/high-voltage-optically-isolated-probes has a short comparison.
Both probes have similar topologies. The Tek IsoVu probe has a 1 GHz probe bandwidth and a <1 GHz probe+oscilloscope bandwidth (when used with a 1 GHz oscilloscope) whereas the Teledyne LeCroy DL-ISO has a 1 GHz probe+oscilloscope bandwidth rating when used with a 1 GHz oscilloscope. Therefore, the IsoVu optical isolated probe usually has a slower rise time when connected to an oscilloscope whereas the Teledyne LeCroy DL-ISO always has the full-rated bandwidth (and a 435 ps rise time) as part of a probe+oscilloscope combination. The Tek IsoVu isolated probe leads are more rigid and less flexible than the Teledyne LeCroy DL-ISO, which is a disadvantage in probing tight circuits. The Teledyne LeCroy DL-ISO has lower noise and high accuracy, and a more faithful signal reproduction. However, the Tek IsoVu benefits from a second-generation design with a smaller probe size. Watch Video Probe Compare: DL-ISO vs. IsoVu for GaN/SiC Measurements for more details.
The amplitudes in 48 to 60V applications are just above the common-mode and differential voltage ratings of conventional differential probes and well below the common-mode and differential voltage ratings of HV differential probes. HV differential probes rated for 1000V common-mode typically have switchable attenuators (e.g., 50x for an ~200V max differential voltage rating, 500x for ~2000V max differential voltage) and the high (50x) attenuation and larger than necessary differential voltage range adds noise to the measurement. Furthermore, most HV differential probes are usually limited to 200 MHz (there are a few exceptions, but 400 MHz is so far the upper limit) which limits their useful in GaN-based designs. Teledyne LeCroy’s DL-HCM is optimized for these voltage ranges in this particular application. Watch Webinar Best Practices for 48 V Power Conversion Testing for more details.
There are many different applications for Si, SiC and GaN designs requiring difference performance and various acceptable price points. Watch Webinar How to Choose the Correct High Voltage Probe for details on selecting the right probe for your application. Watch Webinar High Voltage Probe Real-world Examples and Comparisons for additional details. If you have less time, Read App Note How to Choose the Best High Voltage Oscilloscope Probe in 5 Minutes.
The Teledyne LeCroy DA1855 and DA1855A series of differential amplifiers was manufactured from the late 1990s until the early 2020s. It functioned as a HV differential probe when connected to an oscilloscope with appropriate leads, and had attenuations as low as 1x in some HV modes and 10x gain in other modes, 100 dB CMRR, but only 100 MHz of bandwidth (not suitable for GaN or SiC). The AP033 operates up to 42V common-mode and has 10x gain and is suitable for shunt-resistor measurements. The DL-HCM has attenuation as low as 7x and may function suitable for small-signal measurement. For conduction loss measurements we recommend the technique described in the question “What is the best method to measure MOSFET or IGBT conduction loss?”.
It is not safe to float the oscilloscope above ground – there could be severe injury or death to the oscilloscope operator, damage to the oscilloscope and probe, and damage to the DUT. Floating the oscilloscope also requires a conscious decision to modify the oscilloscope from its stated use. For these reasons, ALL reputable companies and labs strictly prohibit floating an oscilloscope and require use of suitably rated high voltage probes. Furthermore, even if injury or death is avoided, the measurement fidelity of signals acquired by the floated oscilloscope may be impacted.