Devices with signal characteristic dependent control circuitry and methods of operation therefor

An embodiment of a device includes a terminal, an active transistor die electrically coupled to the terminal, a detector configured to sense a signal characteristic on the terminal, and control circuitry electrically coupled to the active transistor die and to the detector, wherein the active transistor die, detector, and control circuitry are coupled to a package. The control circuitry may include a control element and a control device. Based on the signal characteristic, the control circuitry controls which of multiple operating states the device operates. A method for controlling the operating state of the device includes sensing, using the detector, a signal characteristic at the terminal, and determining, using the control device, whether the signal characteristic conforms to a pre-set criteria, and when the signal characteristic does not conform to the pre-set criteria, modifying the state of the control element to alter the operating state of the device.