Digital Gate Driving Unlocks Silicon Carbide’s Full Potential in High-Voltage Power Electronics
October 23, 2023
SiC technology is taking power electronics to new levels of efficiency and power density, solving key challenges as today’s global green initiatives transform entire industries including automotive, industrial, aerospace and defense.
The full potential of these SiC solutions is unleashed when it becomes possible to digitally configure SiC power device switching based on requirements ranging from power levels and switching frequencies to load conditions. This is critical since SiC’s faster switching speed can be accompanied by faster voltage and current transient challenges during switching. These secondary effects can cause voltage spikes, ringing, and electromagnetic interference (EMI), so they require careful circuit design, filtering and other steps that are necessary to prevent device breakdown, unwanted noise and other issues.
Traditional analog MOSFET gate drivers are a clumsy way to perform this task. They were designed to drive much slower silicon insulated-gate bipolar transistors (IGBTs) that exhibit much lower levels of these secondary effects. A much better approach is to control gate driving digitally and optimize switching performance with key-strokes versus what would otherwise have to be done with board re-spins or a soldering gun and bin of gate resistors.
How Digital Gate Drivers Work
Digital gate drivers like Microchip’s mSiC™ gate drivers eliminate these headaches. They can system minimize development time, while enabling easier design upgrades to support future power electronics advances. They reduce switching losses, improve system power density, prevent false faults, and mitigate ringing Electromagnetic Interference (EMI), overshoot and undershoot voltage. The solutions to these problems can be configured digitally with digital gate driving. Gate drive profiles can easily and quickly be modified based on changing application needs. Plus, the gate drivers also incorporate robust short-circuit protection, which is particularly important for SiC MOSFETs at higher DC voltages.
A key element of Microchip’s approach to digital gate driving is its patented Augmented Switching™ technology. It uses configurable profiles to optimize switching efficiency and device characteristics based on application requirements. The profiles, encompassing a series of steps that control voltages and their duration, are implemented for turn-on/turn-off switching. Designers can configure these profiles digitally through software rather than having to make changes in hardware. The technique also includes additional levels of fault monitoring detection and short-circuit response.
Microchip’s mSiC gate drivers speed implementation of these capabilities through plug-and-play mSiC gate driver boards that work out of the box with pre-configured settings for your modules. They also include a programming kit and Intelligent Configuration Tool (ICT) software for additional optimization to meet special application requirements. The boards are optimized for heavy-duty vehicles, Auxiliary Power Unit (APU), charging, storage, inverter and induction heating applications. They can switch up to 200 kHz and provide reporting on up to 7 unique faults and monitoring conditions, including temperature and high voltage monitoring.
Alternatively, developers can opt for digital gate driver cores that enable them to create a fully functional solution with software-configurable ±Vgs gate voltages. Module adapter boards for the digital gate driver cores are also available for evaluation purposes. Finally, digital gate driver development kits are for 1200V and 1700V SiC power modules and are available with or without the SiC power modules.
SiC’s disruptive advantages over silicon IGBTs are fully realized with gate drivers that are smart enough to unlock their high performance. Solutions with configurable turn-on/turn-off capabilities like Microchip’s Augmented Switching technology optimize switching efficiency and device characteristics based on a given application’s unique requirements; helping designers adopt SiC with Ease, Speed and Confidence.