A trigger circuit detects a transient voltage increase on an integrated circuit. The trigger circuit controls a conductivity state of a clamping device to limit the transient voltage increase. The trigger circuit comprises a common capacitive element having a capacitive value, wherein a first time value and a second time value are dependent upon the capacitive value of the common capacitive element, the first time value applicable to an unpowered state of the integrated circuit and the second time value applicable to a powered state of the integrated circuit. The first time value and the second time value control a trigger circuit parameter which may include a detection range within which a rate of transient voltage increase causes the trigger circuit to become active or an “on” time upon which an active duration of control of the conductivity state of the clamping device depends.