A silicon controlled rectifier (SCR) circuit is configured to shunt electrostatic discharge (ESD) current from a node to a reference voltage. The SCR circuit includes a first bipolar PNP transistor having a first emitter connected to the node, a first base, and a first collector. A second bipolar NPN transistor has a second collector sharing a first region with the first base, a second base sharing a second region with the first collector, and an emitter electrically connected to the reference voltage. A guard region is configured and arranged to delay triggering of the SCR circuit in response to an ESD event by impeding current flow in the second region.

Fin field-effect transistor (FinFET) thyristors for protecting high-speed communication interfaces are provided. In certain embodiments herein, high voltage tolerant FinFET thyristors are provided for handling high stress current and high RF power handling capability while providing low capacitance to allow wide bandwidth operation. Thus, the FinFET thyristors can be used to provide electrical overstress protection for ICs fabricated using FinFET technologies, while addressing tight radio frequency design window and robustness. In certain implementations, the FinFET thyristors include a first thyristor, a FinFET triggering circuitry and a second thyristor that serves to provide bidirectional blocking voltage and overstress protection. The FinFET triggering circuitry also enhances turn-on speed of the thyristor and/or reduces total on-state resistance.

FinFET multi-diode thyristor switches for protecting high data rate communication system interfaces are provided. In certain embodiments herein, high voltage tolerant FinFET thyristors are provided for handling high stress current and high RF power handling capability while providing low capacitance to allow wide bandwidth operation. Thus, the FinFET thyristors can be used to provide electrical overstress protection for ICs fabricated using FinFET technologies, while addressing tight radio frequency design window and robustness. In certain implementations, the FinFET thyristors include a first thyristor, a FinFET triggering circuitry and a second thyristor that serves to provide bidirectional blocking voltage and overstress protection. The FinFET triggering circuitry also enhances turn-on speed of the thyristor and/or reduces total on-state resistance.

The present description concerns a device for switching a load, comprising two power thyristors coupled head-to-tail to each other, and a control thyristor having its anode coupled to the gate of a first one of the two power thyristors and having its cathode coupled to the anode of the first one of the two power thyristors.

A semiconductor relay device includes a conversion circuit configured to receive an input signal from outside and pass a first current to a first node based on the input signal. A zener diode has an anode coupled to a second node and a cathode coupled to the first node. A resistor is coupled between the second node and a third node. A number n of diodes are serially coupled. A thyristor has an anode coupled to the first node, a cathode coupled to the second node, and a control terminal coupled to the third node. A transistor has a gate coupled to the first node. An anode of a diode at a first end of the n diodes is coupled to the first node, and a cathode of a diode at a second end of the n diodes is coupled to a third node.