Abstract: A load driver circuit has an output transistor driving the load, with a protective circuit that, when enabled, turns off the output transistor to protect it from high current levels. A delay circuit, which responds to abnormal load conditions after the output transistor has been on for a brief interval, enables the protective circuit to cause turn-off of the output transistor.

Abstract: A technique for detecting misfire due to a fault in the secondary of an automotive ignition system compares the ignition signal developed by the ignition coil, preferably the primary winding thereof, to reference signals. Abnormal results which occur at predetermined times subsequent to the initiation of the ignition signal indicate short circuit and/or open circuit conditions in the ignition system's secondary. In response to such fault conditions, fuel is preferably shut off to the cylinder associated with the misfire.

Abstract: A heat sink assembly for a plurality of transistors includes specially-formed spring clips and a specially-formed heat sink to hold the transistors firmly on the heat sink, and a lead protector that mates with the heat sink to receive and protect the leads of the transistors during handling. The lead protector and the heat sink include integrally-formed fastener/alignment pins for aligning the lead protector with the heat sink, and for aligning the completed heat sink assembly with a circuit board and for holding the assembly securely fastened to the circuit board. A particular feature of the lead protector permits it to mate with heat sink in a first discrete position in which it receives and protects the transistor leads, and to more closely mate with the heat sink in a second discrete position in which the transistor leads pass through the lead protector and into target holes in the circuit board.

Abstract: A solder bonding technique for bonding discrete circuit elements to conductors on an alumina substrate. The conductors are composed of palladium and silver, and atop each conductor at a bonding site, a layer of silver is provided. A layer of solder is disposed over the layer of silver. The compliancy of the silver layer absorbs stresses created by thermal cycles and thereby improves the peel strength of the solder bond.

Abstract: A TAB (Tape Automated Bonding) process uses single-layer tapes to form a semiconductor structure. Beam leads on a metal tape are "inner-lead bonded" to a chip. Each chip site on a specially-formed plastic tape has a central portion and a peripheral portion which are bonded to the chip so that the central portion forms a protective cover over the chip and the peripheral portion acts as a support for the beam leads during probe testing, excising and forming operations, etc. The bottom surface of the chip preferably remains uncovered so that it can, if appropriate, be electrically connected to ground or another potential.

Abstract: The assembly includes a heat-conductive plate onto which a pair of circuit modules are mounted, one module on each side of the plate. A continuous piece of flexible material, such as polyimide, forms the substrate for one circuit module, passes around an edge of the plate, and connects to the other circuit module for which it also forms the substrate. Conductors carried by the flexible material interconnect the modules and also connect the modules to external devices via a connector.

Abstract: An improved semiconductor assembly includes a semiconductor die that is mounted on a carrier, such as a tape or a substrate, by means of an anisotropically electrically conductive adhesive. The adhesive forms an electrically conductive path between electrical conductors on the carrier and other conductors on the die so that the die can be probe tested before the adhesive is cured and before the die is permanently bonded to the carrier.

Abstract: A heat sink has a front side on which a plurality of transistors are situated and a back side in which groooves are formed, each groove being directly opposite a transistor. Two-legged clips each have one leg which holds a transistor against the heat sink and another leg that mates with one of the grooves. A ledge is formed on the front side of the heat sink to form a stop for the bottom edge of each transistor, and each groove terminates in a clip-stop ledge for positioning the leg of a clip. Optionally, a plurality of alignment tabs are formed on the ledge to assist in correctly positioning the transistors.

Abstract: A self-calibrating sensor system is disclosed wherein a processing circuit, normally including an amplifier, receives the output of at least one sensor to develop a processed sensor signal. To compensate for errors (gain error, etc.) in the processing circuit, the preferred embodiment includes a microprocessor which senses certain signals developed by the processing circuit, computes correction factors based on the sensed signals, and then modifies the processed sensor signal so as to substantially eliminate the effect of the errors.

Abstract: Disclosed is an apparatus for pressure sensor compensation. The invention is best suited for pressure sensors of the type which may be mounted about a flexible member such that the resistance of one or more strain gauge resistors mounted thereon changes as pressure is exerted upon the flexible member. The pressure sensing apparatus comprises a bridge resistor arrangement for sensing pressure, and bridge control circuitry, coupled to an input terminal of the bridge, for compensating temperature induced variances in the bridge by controlling the voltage at the input terminal. The bridge has at least a first strain gauge resistor mounted on the flexible member, and at least one output terminal having a voltage which changes as pressure is exerted upon the flexible member. The bridge control circuitry has an additional strain gauge resistor which is used to monitor the temperature of the first strain gauge resistor.

Abstract: Several embodiments for mass airflow sensors are illustrated herein. In each case a sensing element (11) for the mass airflow sensor (10, 34, 50) is provided on a first portion (18) of a thin flexible film substrate (19) while an extension of this substrate provides integral electrical conductive metallizations (24) that connect the sensing element (11) to associated sensor electronic components (21) mounted on a second portion (23) of the film substrate remotely located from the first film portion. This eliminates the need for individual soldered wire connections to connect the sensing element to its associated electronics. In addition, housing portions (12, 13) for the sensor (10, 34, 50) mate together and provide protection for both the sensing element (11) and the sensor electronics (21) thereby providing an integral sensor module including the sensing element and its associated electronics.

Abstract: Inductor coil (13) of a relay (12) used to supply battery power to a power load (11) of a vehicle engine control system (10) is also used to provide a substantially higher than battery voltage (V.sub.Batt) boost voltage (V.sub.Boost) for vehicle control apparatus (20). Microprocessor (21) generates a control signal (V.sub.in) having a 10:1 duty cycle for control of current excitation of the coil (13) during an effective on logic state for the relay (12). During coil current interruptions during the on logic state, energy stored in the inductor (13) is utilized via a rectifier means (26 and 27) to provide the boost voltage. During the on relay state, a movable member (14) of the relay is maintained in its actuated position since current interruptions during the on state are shorter than the relaxation time required for the movable member to assume a nonactuated state.

Abstract: A semiconductor die is mounted on a metal substrate via intermediate layers which permit the die to be readily soldered to the combination while yet reducing thermal stresses. A dielectric layer is formed over the substrate, followed by another layer of a selected metal, either molybdenum or tungsten. Atop the metal layer is another layer comprising a mixture of solder and the selected metal. A layer of only solder is formed over the mixture, and the semiconductor die is bonded thereto by means of the layer of solder.

Abstract: Disclosed is a process which may be used in a communication arrangement between two stations. In at least one of the stations, an MPU is utilized to control an internal operating system and a baud rate generator. The MPU performs periodic self tests to determine how busy it is, and if it is not too busy with internal tasks it calls a baud rate routine to adjust the rate at which the stations are communicating. This periodic testing allows the baud rate to be adjusted according to current environmental conditions. Further, a timer is provided, internal to the MPU, which is used to prevent the baud rate routine from being executed too frequently.

Abstract: A method and apparatus are disclosed for electronically processing a variable frequency input signal and a reference input signal to develop an output signal representative of the frequency difference between the two input signals. The state of the variable frequency signal is sampled upon the occurrence of each leading edge of the reference signal to produce a first output signal. The state of the variable frequency signal is also sampled upon the occurrence of each trailing edge of the reference signal to produce a second output signal. The two output signals are preferably ORed to develop the final output signal.

Abstract: A method and apparatus are described for converting variations in a measured variable (such as pressure) to corresponding variations in an electrical output signal. The preferred method utilizes a capacitive sensor whose capacitance changes to reflect changes in the measured variable. The changes in capacitance are preferably used to vary the gain of a switched-capacitor amplifier whose signal input receives a relatively constant DC reference voltage. The amplifiers' output may be sampled and further amplified to provide an output signal which is indicative of the value of the measured variable.

Abstract: A housing for a circuit board includes a top cover in which a plurality of apertures are formed for receiving wires which are to be bonded to a circuit board located beneath the top cover. Associated with each aperture is a specially formed wire gripper which provides strain relief for the wire which passes through the associated aperture.

Abstract: An electronic circuit is disclosed for detecting a non-operating or fault condition in an alternator. The disclosed embodiment senses the alternator's unrectified output voltage and generates a control signal when the alternator's output voltage fails to exceed a threshold. That threshold is selected to be outside the range of any static voltage the alternator might generate as a result of leakage currents therein. Further circuitry preferably responds to the control signal by generating an indication of a non-operating condition in the alternator.

Abstract: Digital circuitry adaptable for controlling dwell in a spark and dwell ignition control system is disclosed. Maximum advance and reference sensors are utilized to produce pulse transitions which determine positions of maximum and minimum possible advance for spark ignition with respect to the position of the engine crankshaft. For each maximum advance sensor pulse transition a main counter starts a sequential running count of speed independent clock pulses wherein the maximum count obtained by the counter is related to engine crankshaft speed. The running and maximum counts of the main counter are utilized by dwell circuitry to determine the time prior to the next maximum advance pulse at which spark coil excitation should occur.

Abstract: A communication system of the type wherein a central station assigns a limited number of information channels to a requesting one of a plurality of remote stations is disclosed. The requesting station sends its identification signal along with the request signal to the central station on a signal channel. The central station classifies the requesting station in either a priority or a non-priority queue. The priority queue corresponds to those stations which are continuing an on-going interchange, whereas the nonpriority queue contains those stations which wish to initiate an interchange. Stations are prioritized in the queues on a first-in/first-out basis.The central station constantly monitors the information channels and, as channels become available, assigns the channels first to stations in the priority queue, then to nonpriority queue stations.