US Patent 7262946 Integrated electronic disconnecting circuits, methods, and systems

Merged devices for transient blocking. A pass transistor is placed so that its body potential drives the gate of a depletion-mode JFET-type blocking transistor. Thus a transient which appears on an external terminal is very rapidly propagated to shut off the blocking transistor, before large numbers of carriers can be injected. Preferably a shunt device is also used to drop high potentials which may appear at the same time. This connection can be particularly useful in power or data input terminals.