Delphi Technologies, Inc.

Ashraf Kamal Kamel

Kevin M Gertiser

Larry R Hach

Gregory J Manlove

David D Moller

Robert W Koseluk

Duane Donald Fortune

William W Fultz

Dennis P Griffin

Robert K Constable

Gregory Allen Cobb

Terrell Anderson

Richard Joseph Ravas

Thomas L Voreis

James A Kinley

David Robert Arslain

A sensing circuit for detecting open and short circuit conditions in sensors is provided. The sensing circuit includes switching circuitry, a voltage supply, a test capacitor, and an operational amplifier. The switching circuitry is electrically coupled to the voltage supply, test capacitor, operational amplifier, and a sensor. The sensing circuit is configured to provide for a normal operating mode in which the sensing circuit provides an output indicative of a voltage across the sensor, and a charging mode in which the test capacitor is coupled to the sensor and operational amplifier and charged to a steady state, and in which the output of the operational amplifier is a function of the test capacitor capacitance and the capacitance of the sensor. A method for detecting open and short circuit conditions in sensors is also provided.

Sensing circuit and method for diagnosing open and short circuit conditions of a sensor

A sensor interface filter having adjustable gain and Q is provided. The sensor interface includes a first operational amplifier coupled to gain circuitry, a gain stage, and a resistor. The gain circuitry and gain stage are electrically coupled to each other. The gain stage includes a gain stage switch, and is coupled to control circuitry. The control circuitry controls the state of the gain stage switch to vary the number of feedback current paths providing feedback to the inverting input of the first operational amplifier, altering the gain provided by the first operational amplifier. The sensor interface further includes a second operational amplifier coupled to filter circuitry and feedback switches. The feedback switches are coupled to the control circuitry, which controls the state of the feedback switches to vary the gain provided by the second operational amplifier and the filter Q of the sensor interface. A method is also provided.

Sensor interface circuitry having adjustable gain and Q, and method for adjusting sensor interface circuitry gain and Q

The capacitance of a shielded capacitive load cell is determined so as to minimize the effect of stray or parasitic capacitance between the load cell and other objects including the shield. The load cell conductors are coupled across input and output terminals of an operational amplifier that is tied to a reference voltage. A constant current is applied to the load cell, and the resulting rate of change in voltage at the amplifier output is measured as a representation of the load cell capacitance. In a vehicle seat sensor application including an electromagnetic interference shield between the load cell and the seating surface, the amplifier output is coupled to the load cell electrode furthest from the shield, the amplifier maintains the other load cell electrode at a virtual reference voltage, and the shield is tied to the reference voltage.

Shielded capacitive load cell apparatus responsive to weight applied to a vehicle seat

An oxygen sensor interface circuit is configurable on the fly by an electronic controller such as an engine controller to support oxygen sensors having unique interface requirements, to reliably identify various oxygen sensor faults, and to enable rapid detection of a warmed up sensor. The interface circuit is configurable in a first respect to enable operation with any of a number of different sensors, and in a second respect to enable more reliable fault detection, including measurement of leakage to ground or battery.

Configurable interface circuit for exhaust gas oxygen sensors

A slew rate control system for a circuit includes a temperature sensitive device generates a temperature signal. A temperature dependent current source generates a first current source signal. A slew rate controller activates in response to the temperature signal when the temperature exceeds a first threshold. The slew rate controller then generates a slew rate control signal by adjusting slew rate as a function of the temperature signal. The slew rate controller then activates the temperature dependent current source in response to the slew rate control signal.

Dynamic on chip slew rate control for MOS integrated drivers

A circuit for converting an analog signal to a PWM signal samples an amplitude of the analog signal at first sampling rate and a second slower sampling rate, and produces corresponding first and second signals. A comparison signal defines a first state when the first signal is greater than the second signal, and otherwise defines a second opposite state. The PWM signal switches from a first signal level to a second signal level when the comparison signal switches from the first state to the second state only if the comparison signal thereafter remains in the second state for a specified delay period, and the PWM signal switches from the second signal level to the first signal level when the comparison signal switches from the second state to the first state only if the comparison signal thereafter remains in the first state for the delay period.

Circuit for converting an analog signal to a PWM signal

Thermal management of an electronic switch, that provides power to a load, is achieved by monitoring a switch temperature of the electronic switch. When the switch temperature exceeds a first set temperature, the control signal is modified such that an average power dissipated by the electronic switch is reduced. In one embodiment, the control signal is modified by increasing a slew rate of the control signal when the switch temperature exceeds the first set temperature. In another embodiment, a frequency of the control signal is reduced when the switch temperature exceeds the first set temperature.

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Kokomo, IN, United States of America

Ashraf Kamal Kamel