Abstract: A variable capacitance semiconductor device (10) such as a varactor diode, is formed to have a plurality of openings (13), such as a plurality of trenches, that cause the depletion regions (16) to overlap. This overlap results in a rapid change of capacitance for a given change of voltage, and allows efficient operation over a small voltage range.

Abstract: A multi-directional optocoupler includes an assembly substrate (11), an emitter (20) coupled to a first region of the assembly substrate (11), a different emitter (21) coupled to a second region of the assembly substrate (11), a detector (23) coupled to a third region of the assembly substrate (11), a different detector (22) coupled to a fourth region of the assembly substrate (11), a light transmissive region (24) coupling the emitter (20) and the detector (23) wherein the emitter (20) and the detector (23) are configured to transmit and receive a first signal in a direction (26), and a different light transmissive region (25) coupling the different emitter (21) and the different detector (22) wherein the different emitter (21) and the different detector (22) are configured to transmit and receive a second signal in a different direction (27).

Abstract: An optical isolator (10) includes an opto-electronic emitter (16) and an opto-electronic detector (17) mounted over offset portions (12, 13) of a leadframe (11). The offset portions (12, 13) form angles (14, 15) with other portions (24, 25) of the leadframe (11). An optically transmissive material (22) encapsulates the opto-electronic emitter (16) and the opto-electronic detector (17), and a reflective material (20) is located above the opto-electronic emitter (16) and the opto-electronic detector (17). An optically insulative packaging material (26) encapsulates the optically transmissive material (22).

Abstract: A transient protection circuit provides protection from high voltage transients appearing along a transmission line by sensing a predetermined threshold of the voltage developed thereon and opening the conduction path through first and second switching circuits in the transmission line. The switching circuits are implemented with first and second serially coupled transistors sharing a common drain and enabled by a control signal during normal operation. The first and second transistors each have a diode oriented to conduct from the source to the drain for bi-directional operation. During high voltage transient conditions, a sensing circuit detect a predetermined threshold of the potential on the transmission line and disables one of the first and second transistors which opens the conduction path through the first and second switching circuits thereby suppressing the surge currents flowing therethrough.