GaN Systems’ enhanced LTSpice model simulation tool simplifies GaN design

GaN Systems Inc of Ottawa, Ontario, Canada – a fabless developer of gallium nitride (GaN)-based power switching semiconductors for power conversion and control – says that its new set of LTSpice models enables power system design engineers to be fast, accurate and confident with their simulated designs prior to building hardware.

Increasing efficiency and power density requires proper layout and understanding of the characteristics of these fast transistors. GaN Systems provides a full-featured set of LTSpice simulation files (available for download) that allow for a variety of inputs and simulations options – select the product of interest and then select the LTSpice button. LTSpice application notes GN007 and GN008 are also available on GaN Systems’ website.

The LTSpice model user guide helps engineers to model systems at three levels, ranging from an initial overview of circuit performance to detailed analysis and fine tuning of the design:

• Level 1: basic adjustment and analysis of switching speeds, optimized for quick simulation;
• Level 2: includes (in additional to Level 1 features) thermal inputs and Cauer thermal RC network transient models for simulating the device junction temperature and self-heating effect; and
• Level 3: includes (in addition to Level 2 features) parasitic losses, providing the most accurate model with the longest simulation times.

To confirm the accuracy of the LTSpice model, laboratory measurements of GaN E-HEMT switching losses were recorded using a half-bridge, double-pulse test circuit. The measured switching losses were then compared with the LTSpice model simulations. The comparison demonstrates a strong correlation between the simulated results and real-time circuit measurements. With a 400V, 0-30A switching current setup using a 650V, 50mΩ GS65008T device, the difference between actual measurement and the simulated model is less than 5% – a very good number for Eon/Eoff accuracy. The outcome is a simulation tool that provides a convenient and accurate way to understand GaN switching characteristics, evaluate GaN switching performance under different electrical conditions, and build overall confidence in a new product design.

“By developing and making available for download this full-featured LTSpice simulation tool, GaN Systems has made it easier for power system designers to leverage all the benefits of GaN transistors and to optimize their system performance,” says GaN Systems’ VP of sales & marketing Larry Spaziani. “Rarely do designers use spice simulation to estimate Eon/Eoff; with our models they can,” he adds. “This tool will help designers more fully understand GaN technology and accelerate their design completion.”