System Solution Guide: Solid-State Circuit Breaker

Solid-State Circuit Breakers (SSCB) use advanced SiC-based semiconductor technology to provide faster, more reliable, and arc-free circuit protection compared to traditional mechanical breakers. This guide outlines the key components and design considerations for building SSCB systems, including switch types, sensing methods, and integration with wireless communication and ground fault protection. It also features system diagrams, recommended onsemi devices, and simulation tools to support efficient and high-performance SSCB design.

Guide Overview

Solid-State Circuit Breakers (SSCBs) are transforming electrical protection systems by replacing traditional electromechanical breakers with faster, more efficient, and arc-free semiconductor-based solutions. These breakers leverage wide-bandgap technologies like silicon carbide (SiC) JFETs and MOSFETs to enable microsecond fault response, enhanced reliability, and high switching endurance—ideal for applications ranging from EV battery disconnects to industrial power distribution and grid infrastructure.

This solution guide provides a complete overview for engineers designing SSCB systems. It covers key components such as solid-state switches, gate drivers, temperature and current sensing, and integration with wireless connectivity and ground fault protection. You’ll gain insight into AC and DC system topologies, normally-on versus normally-off JFET configurations, and design considerations for thermal management, paralleling devices, and achieving high-efficiency fault interruption.

The guide also features detailed block diagrams and practical application examples, showcasing onsemi’s recommended SiC JFETs, combo devices, and gate drivers. It introduces useful design tools like the CB-JET Simulator and AC Leakage Calculator to help with device selection and thermal analysis. Whether you're building next-gen EV charging infrastructure or intelligent circuit protection systems, this resource equips you with the components and guidance to accelerate your solid-state breaker design.