Abstract: A system current sensor module can accurately sense or measure system current flowing through a sense current resistor by shunting current through a gain-setting resistor and using an amplifier to measure a resulting voltage, with an output transistor controlled by the amplifier controlling current through the gain setting resistor in a manner that tends to keep the amplifier inputs at the same voltage. The resistors can be thermally coupled to maintain similar temperatures when a system current is flowing. The thermal coupling can include conducting heat from a first resistor layer carrying the current sense resistor to a thermal cage layer located beyond a second resistor layer carrying the gain-setting resistor. This preserves accuracy, including during aging.

Abstract: A system current sensor module can accurately sense or measure system current flowing through a sense current resistor by shunting current through a gain-setting resistor and using an amplifier to measure a resulting voltage, with an output transistor controlled by the amplifier controlling current through the gain setting resistor in a manner that tends to keep the amplifier inputs at the same voltage. The resistors can be thermally coupled to maintain similar temperatures when a system current is flowing. The thermal coupling can include conducting heat from a first resistor layer carrying the current sense resistor to a thermal cage layer located beyond a second resistor layer carrying the gain-setting resistor. This preserves accuracy, including during aging.

Abstract: A system current sensor module can accurately sense or measure system current flowing through a sense current resistor by shunting current through a gain-setting resistor and using an amplifier to measure a resulting voltage, with an output transistor controlled by the amplifier controlling current through the gain setting resistor in a manner that tends to keep the amplifier inputs at the same voltage. The resistors can be thermally coupled to maintain similar temperatures when a system current is flowing. The thermal coupling can include conducting heat from a first resistor layer carrying the current sense resistor to a thermal cage layer located beyond a second resistor layer carrying the gain-setting resistor. This preserves accuracy, including during aging.

Abstract: A system current sensor module can accurately sense or measure system current flowing through a sense current resistor by shunting current through a gain-setting resistor and using an amplifier to measure a resulting voltage, with an output transistor controlled by the amplifier controlling current through the gain setting resistor in a manner that tends to keep the amplifier inputs at the same voltage. The resistors can be thermally coupled to maintain similar temperatures when a system current is flowing. The thermal coupling can include conducting heat from a first resistor layer carrying the current sense resistor to a thermal cage layer located beyond a second resistor layer carrying the gain-setting resistor. This preserves accuracy, including during aging.

Abstract: A switching regulator is configured to provide a regulated voltage to a load while maintaining a substantially maximum output current limit, the switching regulator having a loop gain. In accordance with one aspect the switching regulator comprises: a circuit for adjusting the maximum output current limit in response to a programmable signal independently of the loop gain. In accordance with another aspect, the switching regulator comprises: a resistance sensing element for providing the current output of the regulator, and having a resistance which varies with temperature; and a circuit for maintaining the output current limit at a level independent of the temperature of the sensing element. In addition, in accordance with one aspect, a method of providing a regulated voltage to a load is disclosed in which a substantially maximum output current limit of a switching regulator is maintained.

Abstract: A switching regulator is configured to provide a regulated voltage to a load while maintaining a substantially maximum output current limit, the switching regulator having a loop gain. In accordance with one aspect the switching regulator comprises: a circuit for adjusting the maximum output current limit in response to a programmable signal independently of the loop gain. In accordance with another aspect, the switching regulator comprises: a resistance sensing element for providing the current output of the regulator, and having a resistance which varies with temperature; and a circuit for maintaining the output current limit at a level independent of the temperature of the sensing element. In addition, in accordance with one aspect, a method of providing a regulated voltage to a load is disclosed in which a substantially maximum output current limit of a switching regulator is maintained.

Abstract: A sensor module is provided having a compact housing containing a sensor. A low temperature co-fired ceramic substrate is located on the housing. The sensor and signal processing circuitry are located on the low temperature co-fired ceramic substrate. The sensor module further includes a metal shield substantially encapsulating the sensor.

Abstract: A transceiver for transmitting and receiving satellite RF signals is provided. The transceiver includes RF front-end receiver circuitry capable of receiving FM radio broadcast RF signals and converting the FM radio broadcast RF signals to an intermediate frequency. The RF front-end receiver circuitry is configured to receive RF signals at greater than 108 MHz and convert the RF signals to an intermediate frequency. The transceiver also includes signal processing circuitry including at least one DSP core for demodulating intermediate frequency signals provided by the front-end circuitry and for modulating data to be transmitted into baseband modulated data signals, and at least one audio output. The transceiver further includes RF transmitter circuitry configured to convert the baseband modulated data signals provided by the at least one DSP core into modulated transmit signals having a frequency greater than 108 MHz for transmission and transmit the modulated transmit signals.

Abstract: 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.

Abstract: A pressure sensor module is provided with an isolation platform which isolates stress. The pressure sensor module includes a base structure and a cantilever member formed in the base structure by an isolation gap. A pressure sensing element is located on the cantilever member such that the cantilever member provides stress isolation to the pressure sensing element.

Abstract: Analog signal conditioning circuitry is provided for processing an analog signal generated by a sensor to remove DC offset. The signal conditioning circuitry includes an amplifier having the first input receiving an analog input signal and a second input receiving a reference signal. The amplifier includes an output providing an analog output signal defined by an amplified representation of the analog input signal and the reference signal. The circuitry includes a feedback circuit having an input coupled to the amplifier output and an output coupled to the first input of the amplifier for providing an analog feedback signal. The feedback circuit includes an analog-to-digital converter for converting the analog amplifier output to a digital signal, a digital controller for processing the digital signal, and a digital to analog converter for converting the processed digital signal to an analog feedback signal.

Abstract: 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.

Abstract: Analog signal conditioning circuitry is provided for processing an analog signal generated by a sensor to remove DC offset. The signal conditioning circuitry includes an amplifier having the first input receiving an analog input signal and a second input receiving a reference signal. The amplifier includes an output providing an analog output signal defined by an amplified representation of the analog input signal and the reference signal. The circuitry includes a feedback circuit having an input coupled to the amplifier output and an output coupled to the first input of the amplifier for providing an analog feedback signal. The feedback circuit includes an analog-to-digital converter for converting the analog amplifier output to a digital signal, a digital controller for processing the digital signal, and a digital to analog converter for converting the processed digital signal to an analog feedback signal.

Abstract: 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.

Abstract: A variable reluctance sensor interface module having a variable attenuation circuit and a rectifier and differential to single-ended conversion circuit for operating in a current mode to attenuate a differential input voltage. The variable attenuation circuit receives an input differential voltage from a magnetic sensor, converts the differential voltage to current, and variably attenuates the current. The rectifier and differential to single-ended conversion circuit converts the variably attenuated current to a voltage output. The input circuit includes an RC filter that attenuates high frequency signals. An initial threshold circuit generates an initial threshold voltage that compensates for internal resistance variations.

Abstract: A variable reluctance sensor interface module having a variable attenuation circuit and a rectifier and differential to single-ended conversion circuit for operating in a current mode to attenuate a differential input voltage. The variable attenuation circuit receives an input differential voltage from a magnetic sensor, converts the differential voltage to current, and variably attenuates the current. The rectifier and differential to single-ended conversion circuit converts the variably attenuated current to a voltage output. The input circuit includes an RC filter that attenuates high frequency signals. An initial threshold circuit generates an initial threshold voltage that compensates for internal resistance variations.

Abstract: A non-linear temperature compensation circuit (10) is provided for generating at least dual-slope characteristics responsive to changes in operating temperature of the compensation circuit. The compensation circuit includes a temperature dependent current generator circuit (11) for generating at least one output (I4) substantially proportional to changes in the temperature of the circuit, a current-based dual-slope drift generator (12) for generating a current proportional to absolute temperature, and a summing means (14) for summing both current outputs and generating a compensation drift voltage. The temperature dependent current generator includes a sub-circuit having a first current generator that generates a current (I2) that is relatively independent of temperature, and a second current generator that generates a second current (I3) that decreases with increases in temperature.

Abstract: An error detection circuit for an airbag deployment control system includes a delay circuit receiving an analog acceleration signal, a difference circuit producing a difference signal based on a time difference between the original and delayed acceleration signals, and a first comparator circuit comparing the difference signal to first and second threshold signals. If the difference signal falls within an error region defined between the first and second threshold values, a decision circuit inhibits an otherwise pending airbag deployment event. If, on the other hand, the difference signal falls outside of the error region, the decision circuit allows airbag deployment with minimal delay.

Abstract: An adjustable voltage controlled oscillator has an input for receiving a voltage signal and an integrator coupled to the input for generating a ramp signal. The circuit also includes an adjustable current supply coupled to an output of the integrator for supplying an adjustable amount of current. A comparator compares the ramp signal with a predetermined voltage. The circuit further includes an output for generating a frequency output as a function of the comparison, wherein the circuit is calibratible by adjusting current generated by the adjustable current supply.

Abstract: An error detection circuit for an airbag deployment control system includes a delay circuit receiving an analog acceleration signal, a difference circuit producing a difference signal based on a time difference between the original and delayed acceleration signals, and a first comparator circuit comparing the difference signal to first and second threshold signals. If the difference signal falls within an error region defined between the first and second threshold values, a decision circuit inhibits an otherwise pending airbag deployment event. If, on the other hand, the difference signal falls outside of the error region, the decision circuit allows airbag deployment with minimal delay.