Abstract: A structure and method for guarding a high voltage region at a semiconductor surface from a low voltage region at the semiconductor surface. The structure comprising at least two trenches between the high and low voltage regions to isolate the high voltage region from the low voltage region. The trenches are spaced apart so as to define a sub-region therebetween. To prevent breakdown across the trenches, an intermediate voltage, i.e., of a value between the voltages of the high and low voltage regions, is applied to the sub-region so as to reduce the voltage drop across each trench. Preferably this is achieved by providing an integrated voltage divider circuit that connects between the high and low voltage regions and has an output connected to the sub-region by which the intermediate voltage is applied to the sub-region.

Abstract: An inverter logic circuit includes a bipolar junction transistor and a zener diode. The zener diode is connected between the base of the bipolar junction transistor and ground (or other reference voltage). The zener diode is reverse biased such that a leakage current through the zener diode allows for sufficient current through the emitter-base terminals of the bipolar junction transistor when a voltage is applied across the emitter and base terminals of the bipolar junction transistor to turn the transistor ON in the absence of an external signal to the base. As such the bipolar junction transistor functions as a normally ON bipolar junction transistor.

Abstract: An inverter logic circuit includes a bipolar junction transistor and a zener diode. The zener diode is connected between the base of the bipolar junction transistor and ground (or other reference voltage). The zener diode is reverse biased such that a leakage current through the zener diode allows for sufficient current through the emitter-base terminals of the bipolar junction transistor when a voltage is applied across the emitter and base terminals of the bipolar junction transistor to turn the transistor ON in the absence of an external signal to the base. As such the bipolar junction transistor functions as a normally ON bipolar junction transistor.

Abstract: A circuit including: a transistor, a base of the transistor being switchably connectable to a signal source; and a first diode connected between the base and a reference voltage. The circuit is arranged such that when the signal source is not connected to the base of the transistor, a voltage applied at an emitter of the transistor causes a current flow through the base of the transistor and through the first diode such that the transistor is in an ON state, and when the signal source is connected to the base of the transistor, current flow through the base reduces such that the transistor switches to an OFF state. The circuit includes a second diode, and the signal source is connectable to the base of the transistor through the second diode.

Abstract: A controller adapted to operate a driver circuit of Bipolar Junction Transistors (BJT) such that within each ON-OFF switching cycle of the BJT, the output of the driver circuit is in the floating state for longer than it is in either the ON or OFF state. In the floating state the driver circuit is not drawing power and so power efficiency is improved. The circuit may include a bypass connection between the base and collector terminals of the BJT. The resistance of the bypass connection is selected to decay charge in the drift region whilst the transistor is ON to reduce the switching time of the BJT.

Abstract: A bipolar transistor having a semiconductor structure that includes a channel of semiconductor type that is the same as the collector and emitter regions. The channel is significantly shallower than the base region with which it interfaces. The semiconductor structure provides improved current gain. It also enables the device to operate, when on, selectively either with primarily unipolar conduction or with primarily bipolar conduction by control of the voltage across the emitter and collector terminals of the transistor.

Abstract: A structure and method for guarding a high voltage region at a semiconductor surface from a low voltage region at the semiconductor surface. The structure comprising at least two trenches between the high and low voltage regions to isolate the high voltage region from the low voltage region. The trenches are spaced apart so as to define a sub-region therebetween. To prevent breakdown across the trenches, an intermediate voltage, i.e., of a value between the voltages of the high and low voltage regions, is applied to the sub-region so as to reduce the voltage drop across each trench. Preferably this is achieved by providing an integrated voltage divider circuit that connects between the high and low voltage regions and has an output connected to the sub-region by which the intermediate voltage is applied to the sub-region.

Abstract: A circuit including: a transistor, a base of the transistor being switchably connectable to a signal source; and a first diode connected between the base and a reference voltage. The circuit is arranged such that when the signal source is not connected to the base of the transistor, a voltage applied at an emitter of the transistor causes a current flow through the base of the transistor and through the first diode such that the transistor is in an ON state, and when the signal source is connected to the base of the transistor, current flow through the base reduces such that the transistor switches to an OFF state. The circuit includes a second diode, and the signal source is connectable to the base of the transistor through the second diode.

Abstract: An inverter logic circuit includes a bipolar junction transistor and a zener diode. The zener diode is connected between the base of the bipolar junction transistor and ground (or other reference voltage). The zener diode is reverse biased such that a leakage current through the zener diode allows for sufficient current through the emitter-base terminals of the bipolar junction transistor when a voltage is applied across the emitter and base terminals of the bipolar junction transistor to turn the transistor ON in the absence of an external signal to the base. As such the bipolar junction transistor functions as a normally ON bipolar junction transistor.