Abstract: An integrated circuit with a buried layer for increasing the Q of an inductor formed in the integrated circuit. The substrate includes a highly doped buried preserving device and latchup characteristics. The inductor may also include an increased thickness conductive layer in the inductor to further increase Q. The present invention is also directed to a low loss interconnect.

Abstract: A line transformer circuit in which the DC component of magnetization produced in the tip and ring windings by the battery supplying loop current to the telephone set microphone may be neutralized by an oppositely-poled, serially-connected balancing winding is disclosed. One end of the balancing winding is connected to the supply battery and is, therefore, at AC ground. The other end is kept at a point of high AC impedance to ground by the collector of a transistor so that audio frequency voltages induced in the balancing winding cannot load the transformer. The AC currents in the tip and ring windings are provided with a virtual ground return path by means of a differential amplifier controlled Darlington pair in circuit between the tip and ring windings and the balancing winding. The AC components of the Darlington pair collector current are bypassed to ground by a shunt capacitor at the junction of the Darlington pair collector terminal and the third winding.

Abstract: An electronic switch is disclosed comprising a transistor bridge having input and output signaling nodes and bias control nodes. A pair of matched current sources are selectively activated and deactivated in a series arrangement with symmetrical turn-on turn-off circuitry in response to a receipt of instruction signals. The instruction signals control the gating of a constant current to the turn-on/off circuitry for enabling the matched current sources to selectively apply and withdraw matched currents from bias control nodes. Switched turn-off circuitry is employed for reverse biasing the transistor bridge in response to a deactivation of the matched current sources. A pair of voltage reference and antisaturation circuits cooperate with bridge discharge circuits to effect the reverse biasing of the bridge and to discharge rapidly the effective electrical capacitance of that bridge shortly after the receipt of a bridge turn-off instruction.

Abstract: This specification discloses transistor circuitry suitable for use as a switch or as a floating current driver to control the concurrent operation of a pair of utilization devices. The circuitry comprises an NPN and a PNP output transistor which are substantially simultaneously switchable to ON and OFF states by a bias control means. The output transistors each have a collector connectable to a utilization device and a voltage of a prescribed polarity. Emitters of the output transistors are connected together in a floating voltage arrangement via a resistor. The bias control means comprises a pair of NPN transistors and a diode connected PNP transistor illustrated for switching the NPN output transistor and then the PNP output transistor to ON and OFF states. A logic gate switches a constant current to the bias control transistors for controlling the switching operations.