Oscilloscope-based double pulse test solution for SiC and GaN technologies

Tektronix, Inc has released its new Double Pulse Test (WBG-DPT) solution. With new wide bandgap switching devices allowing significant advances in EVs, solar energy and industrial controls, the solution can provide automated, repeatable, and accurate measurements on wide bandgap devices such as SiC and GaN MOSFETs.

Designers of next-generation power converters will now be able to utilise the WBG-DPT solution to optimise their designs confidently and quickly. With the ability to run on Tektronix 4, 5 and 6 Series MSO oscilloscopes, integrating seamlessly into the measurement system of the oscilloscopes, the WBG-DPT Solution boasts several industry-first measurement capabilities, such as an automatic WBG deskew technique and reverse recovery timing plots, making it easier for engineers to see reverse recovery details for multiple pulses overlaid on a single display. Measurements are also designed to align with JEDEC and IEC standards for double pulse testing and diode reverse recovery.

“Tektronix customers are the designers of the next generation of cutting-edge power electronics technology, and their designs must be optimised to balance efficiency, size and reliability,” shares Daryl Ellis, Tektronix Mainstream Portfolio General Manager. “We are confident that the design of the Tektronix WBG-DPT Solution will allow for simplified debugging, repeatable measurements (per JEDEC and IEC standards) and a faster learning curve. Test automation reduces test times and retesting errors, ensuring our customers meet their project timelines and time-to-market plans.”

“The WBG-DPT software provides instantaneous measurements of key parameters, like EON, EOFF, and QRR, when performing double-pulse tests,” said Masashi Nogawa, staff systems engineer at Qorvo. “The software makes the power waveform and markers showing the integration ranges used to calculate the energy losses immediately visible. This is an excellent alternative to exporting waveform data into Excel spreadsheets for processing.”

To achieve meaningful energy loss measurements, designers must correct for delays introduced by test fixtures and probes. The traditional technique for aligning drain-to-source-voltage (VDS) and drain current (ID) measurements require rewiring the test setup and careful pretest measurements.

The sSolution’s industry-first WBG deskew technique eradicates the need for rewiring and may even be performed after double pulse measurements have been taken. The software generates an alignment waveform to simulate the effects of delays in the test setup. The engineer adjusts a few settings to match the alignment waveform with the measured waveform, as the software corrects any differences in delays. This new process reduces the deskew time from an hour or more to just five to ten minutes.

Since power converters must operate over a wide range of temperature conditions, there is a growing need to measure output charge (QOSS) at different junction temperatures. The Tektronix WBG-DPT Solution boasts fast and accurate QOSS measurements, providing important insight into the effects of device output capacitance.

With the solution, industry-first reverse recovery timing plots make it easy for engineers to see reverse recovery details for multiple pulses overlaid on a single display. Measurements are made per JEDEC and IEC standards, and users can configure measurements in the WBG solution to query results on every first or second pulse or all pulses of a double-pulse set. This unique approach to reverse recovery plotting allows for multiple double pulse sets and provides visual and measurement results on each set. The measurement offers the ability to easily zoom in on the reverse recovery region and even debug reverse recovery parameters of the system.