Solid-state circuit breakers (SSCBs) are advanced, semiconductor-based protection devices that replace mechanical contacts with electronic switching. They offer ultra-fast response and arc-free operation.
Solid-state circuit breakers (SSCBs) are an emerging alternative to conventional electromechanical circuit breakers, using semiconductor switches instead of mechanical contacts to interrupt fault currents. By eliminating moving parts and electrical arcing, SSCBs provide microsecond-level fault interruption, improved reliability, longer operational life and programmable protection settings. These capabilities make them well suited for DC power distribution, battery energy storage systems, EV charging infrastructure, industrial automation and modern smart-grid applications.
Compared with conventional breakers, SSCBs offer several significant advantages. Mechanical breakers typically require milliseconds to interrupt fault currents and suffer from contact wear, arcing and limited switching life. In contrast, SSCBs can clear faults hundreds of times faster, reducing fault energy and improving system protection. Semiconductor switching eliminates contact erosion and arc-suppression requirements, enabling virtually unlimited switching cycles and higher operational reliability. SSCBs also support adaptive protection thresholds, remote monitoring, diagnostics and communication capabilities that allow integration into intelligent energy-management systems and Industry 4.0 infrastructures.
The core of an SSCB is the solid-state switch, typically implemented using silicon carbide (SiC) JFETs, SiC Combo JFETs or SiC MOSFETs. Wide-bandgap SiC devices offer low conduction losses, high voltage capability, excellent thermal performance and fast switching speed, enabling efficient interruption of high fault currents. Current design trends favor parallelized SiC devices, advanced gate control and optimized dv/dt management to reduce EMI, improve efficiency and support scalable power levels from low-voltage DC systems to medium-voltage applications.
Safety and compliance are vital in SSCB design. Engineers must validate device operation within SOA limits, ensure fail-safe behavior during power loss, and protect against ESD, surges, and EMI. Key standards include IEC 60947 (low-voltage switchgear), IEC 61000 (EMC compliance), UL 489 (circuit protection), and IEC 61508 (functional safety). Advanced SiC technologies, intelligent sensing, and high-speed protection enable compact, efficient, and connected SSCBs.
The future of circuit protection is SiC JFET-based. Watch the webinar and download the tutorial to dive into smart, efficient solid-state design.
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Interest in solid-state circuit breakers is rising, and SiC FETs offer a simplified path to high-current DC and AC protection solutions.
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Our SiC MOSFETs are designed to be fast and rugged and include system benefits from high efficiency to reduced system size and cost. MOSFETs are metal–oxide–semiconductor field-effect transistors with insulated gates. These silicon carbide MOSFETs have a higher blocking voltage and higher thermal conductivity than silicon MOSFETs, despite having similar design elements. SiC power devices also have a lower state resistance and 10 times the breakdown strength of regular silicon. In general, Systems with SiC MOSFETs have better performance and increased efficiency when compared to MOSFETs made with silicon material.
There are many advantages to choosing SiC MOSFETs over silicon MOSFETs, such as higher switching frequencies. High-temperature development is also not a concern when using SiC MOSFET modules because these devices can operate efficiently even in high heat. Additionally, with SiC MOSFETs, you benefit from a more compact product size because all components (inductors, filters, etc.) are smaller.
The white paper traces the origins and evolution of the SiC FET to its latest generation and compares its performance with alternative technologies.
Watch and learn how SiC JFETs and Combo JFETs enable faster, safer, and smarter solid-state circuit breaker designs for high-voltage applications.
Explore a comprehensive Solid-Stare Circuit Breaker diagram handbook for low and medium voltage systems with system‑level block diagrams, topologies, describing solid-state switch stage, sensing, protection, and general design guidelines.
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A solid-state circuit breaker is an electronic protection device that uses semiconductor switches instead of mechanical contacts to interrupt fault currents. SSCBs provide microsecond-level response times, eliminate arcing and enable intelligent monitoring and control functions.
SiC Combo JFETs integrate a normally-on SiC JFET and a low-voltage silicon MOSFET into a normally-off solution. They provide ultra-low RDS(on), improved paralleling capability, controllable switching speed and integrated temperature-monitoring capabilities through direct access to both JFET and MOSFET gates.
SSCBs typically use current-sensing amplifiers, shunt resistors, voltage sensing circuits, comparators and ADCs to detect abnormal operating conditions. Fast hardware-based protection paths allow the system to react within microseconds before semiconductor stress limits are exceeded.
Modern SSCBs often include CAN, Ethernet, Single Pair Ethernet and Bluetooth connectivity to support remote monitoring, predictive maintenance, firmware updates and integration into smart-grid, industrial automation and energy-management systems.
The shift toward renewable energy, battery energy storage systems, EV charging infrastructure, DC microgrids and smart industrial facilities is accelerating demand for SSCBs. Key technology trends include increased adoption of wide-bandgap semiconductors, intelligent digital protection algorithms, integrated sensing and communication capabilities, and scalable architectures for medium-voltage DC applications.
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