Circuits, integrated circuits, apparatuses, and methods, such as those for protecting circuits against electrostatic discharge events are disclosed. In an example method, a thyristor is triggered to conduct current from a signal node to a reference voltage node using leakage currents provided by a transistor formed in a semiconductor doped well shared with the base of the thyristor. The leakage currents are responsive to a noise event (e.g., electrostatic discharge (ESD) event) at the signal node, and increase the voltage of the semiconductor doped well to forward bias the base and the collector of the thyristor. The triggered thyristor conducts the current resulting from the ESD event to the reference voltage node.