General Electric Company

Robert G Hodgins

Hamza Yilmaz

Edward K Howell

Donald L Watrous

Mike F Chang

King Owyang

Robert S Wrathall

Peter J Carlson

The junction temperature rise of a power MOSFET serially connected to a lamp whose resistance nonlinearly increases during turn-on is moderated by the use of control circuitry which initially sets up a relatively low essentially constant current flow through the lamp and transistor and then automatically after the lamp resistance reaches a preselected level, the lamp is allowed to draw significantly more current. The size and therefore cost of the power MOSFET is reduced significantly because the magnitude of the current spike generated by turning on the lamp is significantly reduced the use of the novel control circuitry.

Soft start solid state switch

A process for fabricating a power IC structure which includes the following masking steps:

Method of making a power IC structure with enhancement and/or CMOS logic

A disclosed MOSFET cell has a source region formed at the top surface of a semiconductor substrate. The top surface source region is electrically coupled to a conductive region at a bottom portion of the substrate by means of a vertical conduit which projects through the substrate from the top surface to the conductive region. A current exchanger is provided extending over the top surface of the substrate and coupling a top surface portion of the vertical conduit to the source region. The current exchanger makes ohmic contact with the source region and with the conduit region and shorts the two regions together such that majority carrier current of the conduit region will be 'converted' into majority carrier current of the source region and electrical continuity between the source region and the conductive region of the substrate is established. Respective source regions of multiple MOSFET cells may be interconnected in accordance with this method through a longitudinally extending conductive layer which is typically formed near the bottom surface of semiconductor substrates.

Mosfet structure with substrate coupled source

A pass transistor is coupled serially with an integrated circuit across a DC energy source. The DC source includes a battery coupled in parallel with a charging transformer output and a diode, the negative side being connected to ground. A resistor is coupled across the pass transistor collector and base to assure conduction by the pass transistor when the DC source is operative. A string of zener diodes is connected between the pass transistor base and ground to provide voltage limiting by clamping the transistor base during an overvoltage condition arising, for example, when the battery has a defective cell or an open connection to the remainder of the circuit. Such an arrangement allows reliable operation with monolithic transistors having about 27 volts collector to emitter breakdown voltage rating.

Overvoltage protection for an integrated circuit

An electronic module for ground fault circuit interrupters (GFCI) in both circuit breaker and receptacle configurations includes a signal processor having a plurality of fault signal threshold stages for differentially charging an integrating capacitor in accordance with the magnitude of the fault signal as amplified by a high gain differential amplifier. The accumulated charge on the integrating capacitor controls the generation of a trip signal. The processor also includes a highly stable grounded neutral excitation oscillator and a noise rejection network to combat nuisance tripping.

Growing community of inventors

Raleigh, NC, United States of America

Robert G Hodgins