Double-pulse testing of SiC, GaN, MOSFET & IGBT devices

Double-pulse testing (DPT) is the core method for evaluating the dynamic behaviour of power switches — MOSFETs, IGBTs and the new wide-bandgap SiC and GaN devices driving EV inverters, chargers and solar converters. Two gate pulses through an inductive load reveal switching energies, timing and diode reverse recovery at precisely controlled current.

Why it's demanding

• Speed: SiC/GaN edges are in the nanosecond range (GaN reverse recovery can be <10 ns) — you need 500 MHz+ of clean bandwidth or the switching losses are simply wrong
• Common-mode interference: on an 800 V bus the common-mode swing reaches kilovolts; ordinary differential probes lose CMRR at high frequency and paint false oscillations onto V_GS
• Data volume: dozens of parameters (E_on, E_off, t_r, t_f, dv/dt, di/dt, Q_rr…) per device corner — manual analysis is slow and error-prone

The Siglent solution stack

• SDS5000X HD / SDS3000X HD 12-bit oscilloscope — high resolution keeps both the kV-scale drain voltage and the mV-scale details honest
• ODP6000B optical-isolated probes — 160 dB CMRR via fibre-optic isolation for gate-source measurements on the high side
• Current measurement via shunt or CP-series current probe
• Siglent DPT software — sequences the pulses, auto-identifies the switching regions, extracts the full parameter table and exports an HTML/XML report

What you get

• Switching parameters: E_on, E_off, V_peak, I_peak
• Timing: t_d(on), t_d(off), rise and fall times
• Diode reverse recovery and capacitance analysis
• A generated report with screenshots and tables — the factory quotes an efficiency gain of 80 % versus manual processing