Abstract: A planar transformer assembly includes an insulative layer, a first spiral winding thereon circumscribing a magnetic flux path, a second spiral winding thereon in non-overlapping relation to the first spiral winding circumscribing the magnetic flux path, and a ferrite core assembly including first and second core sections defining a shallow gap or passage within which the spiral windings are disposed. In one embodiment, a plurality of laminated insulative layers are provided with a primary winding including a plurality of series-connected spiral subwindings and a non-overlapping secondary winding formed on the various insulative layers. The non-overlapping structure and the order of the various windings minimize electric field gradients and thereby minimize electric field coupled noise currents.

Abstract: An integrated circuit photodetector includes a transimpedance amplifier including a differential amplifier stage with PNP emitter-coupled transistors and a PNP input transistor which are biased only by base currents of the emitter-coupled transistors, to achieve low input bias current. Low noise operation is achieved by bypass capacitors coupled between the bases and emitters of the input transistors, respectively. A constant current source supplies a current which develops a small pedestal voltage across a resistor to bias the non-inverting input of the transimpedance amplifier so as to avoid nonlinear amplification of low level light signals. A positively biased N-type guard tub surrounds the photodetector, which is formed in a junction-isolated N region on a P substrate, to collect electrons generated in the substrate by deep-penetrating IR light to prevent them from causing amplification errors.

Abstract: A planar transformer includes a multilayer printed circuit board having a plurality of spiral windings formed by metalization on various surfaces of the printed circuit board. A ferrite core assembly includes first and second core sections disposed on opposite sides of the printed circuit board and completely confining the conductors of the spiral windings. Each core section includes a thin, flat plate. The two flat plates are integral with or abut thin post sections that are thick enough to allow the printed circuit board to be accommodated between the first and second core sections. In one embodiment of the invention, the planar transformer is incorporated on the printed circuit board with other circuitry to form a low noise battery charger which is encapsulated in a male power connector.

Abstract: A square toroid transformer is assembled on a ceramic hybrid integrated circuit substrate. The primary and secondary windings of the transformer are provided on opposite arms of a square toroid ferrite core by providing first and second groups of spaced, parallel metal conductors on the surface of the ceramic substrate and adherent thereto, and an insulative layer over the first and second groups of conductors, leaving their respective end portions exposed. The square toroid ferrite core, coated with dielectric material, is attached to the insulative layer. Wire bonds in planes perpendicular to the longitudinal axes of the opposite arms each are wire bonded, respectively, to an inner end of one of the metal conductors and an outer end of an adjacent one.

Abstract: A vacuum chuck for securely holding integrated circuit hybrid package substrates in fixed relationship to an X/Y table that is subjected to severe repeated lateral acceleration and decceleration forces to prevent appreciable lateral displacement of the package substrate relative to the X/Y table. A plurality of shallow, closed loop grooves are disposed in the chuck. A resilient O ring is disposed in each groove and normally extends a small but precise amount above the surface of the base. A vacuum path opens into each region circumscribed by an O ring. When a package substrate is positioned on an O ring and the vacuum then is applied, the O ring is compressed, causing the sides of the O ring to tightly engage the walls of the groove, preventing the O ring from "rolling" in the groove as a result of lateral acceleration and decceleration forces on the package.

Abstract: A dual cavity semiconductor package containing a high voltage (greater than 1500 volts) isolation amplifier includes a ceramic substrate with tungsten metalization thereon defining die bonding and wire bonding sites and interconnections in the two cavities for input and output circuitry of the isolation amplifier, respectively. The metalization also defines a pair of precisely matched planar fringe capacitors forming a high voltage small signal isolation barrier located between the two cavities. A layer of ceramic having apertures therein defining the two cavities is laminated over the substrate. The assembly is cofired at about 2,000.degree. Centrigrade, causing ceramic to fill the gaps between the conductors of the fringe capacitors, providing very high voltage isolation therebetween. Separate tungsten sealing rings are provided around the peripheries of the cavities on the top surface of the second layer.

Abstract: A square toroid transformer is assembled on a ceramic hybrid integrated circuit substrate. The primary and secondary windings of the transformer are provided on opposite arms of a square toroid ferrite core by providing first and second groups of spaced, parallel metal conductors on the surface of the ceramic substrate and adherent thereto, and an insulative layer over the first and second groups of conductors, leaving their respective end portions exposed. The square toroid ferrite core, coated with dielectric material, is attached to the insulative layer. Wire bonds in planes perpendicular to the longitudinal axes of the opposite arms each are wire bonded, respectively, to an inner end of one of the metal conductors and an outer end of an adjacent one.

Abstract: A single reflective afocal optical module collects and concentrates solar energy onto a receiving surface extending substantially parallel to the focal axis of the optical system and to the central axis of the module. The reflective surface of the collector is shaped to reflect incoming energy and distribute it uniformly over the full surface of the receiver, with the reflective surface preferably consisting of a plurality of discrete reflective surface portions each distributing its portion of reflected energy over the full receiver surface so that the energy portions from the respective reflective surface portions are superimposed on one another on the receiver. The reflector and receiver are housed in a sealed enclosure having a transparent window for admitting incoming energy, and heat extracting means removes excess heat from the enclosure.

Abstract: Modular structures for the collection, concentration and conversion of solar energy to another usable form such as electrical energy. The structures feature three conic section reflective surfaces, two of which focus in front of a receiver element and off the axis of the structure. The third reflective surface is utilized to redirect that energy which would otherwise miss the receiver element to improve overall efficiency.