Littelfuse manufactures an extensive portfolio of circuit protection devices, including fuses, polymer-based resettable circuit protectors, varistors, and gas discharge tubes. Beyond circuit protection, its product lines feature advanced power control semiconductors, specialized automotive and industrial sensors, electromechanical switches, heavy-duty relays, and microprocessors through its subsidiary Zilog. These mission-critical components protect electronic systems from overcurrent, overvoltage, and electrostatic discharge across diverse end-use applications.