Texas Instruments Corporation

Other

Thomas Richard Maher

Keith W Kawate

David L Corkum

Norman E LeComte

Sepideh H Nott

Eric K Larson

Alexander Noam Teutsch

Timothy John Legat

Ross Elliot Teggatz

Peter A Weise

Dale R Sogge

Paulus Thomas Johannes Gennissen

Douglas B Strott

Thomas J Charboneau

Marc Gerard Johan Borgers

Timothy M McBride

John J Chrupcala

John A Powning

Morgan Maher

Charlie Centofante

Larry Maher

Jim Jacques

Chris D Wagner

A semiconductor device suitable for use in a pressure sensor is disclosed. A uniformly thin die is provided by chemically etching a back side of a wafer. Piezoelectric elements formed integrally within the die generate electrical signals in response to flexing the die. Conductive leads formed integrally within the die electrically communicate the generated electrical signals to support circuitry formed integrally within the die proximate the piezoelectric elements. In an example embodiment, the piezoresistive elements take the form of silicon resistors formed integrally via doping and diffusion in a Wheatstone bridge configuration. In one application, the die serves as a deformable diaphragm, seated atop an aperture of a threaded pressure sensor housing.

Semiconductor device with integrated piezoelectric elements and support circuitry

The formation of a semiconductor sensing device is disclosed, where the device can be used to sense pressure, for example. The device is formed by etching the entire backside of a semiconductor substrate or wafer. This streamlines the fabrication process by omitting a number of steps that would otherwise be required to selectively etch certain locations of the substrate. This also improves device performance and compactness by allowing associated support circuitry to be formed closer to a sensing region, and more particularly piezoelectric elements of the sensing region.

Full backside etching for pressure sensing silicon

A memory chip and embedded microprocessor ('smart memory card') with a sputtered memory ring for additional memory capacity. The card configuration allows use with ISO 7816 compliant readers. The smart memory card has a spring bolt-hole which allows use of the smart memory card on an adaptor with compact disc and digital video disc drives. The memory chip and sputtered memory ring have sufficient capacity for high-density memory applications such as high-level encrypted security systems, biometric identification systems, and combination access systems. The processor configuration may include a wireless transceiver for 802.11 series, Bluetooth&#x2122; and other wireless systems.

CruzCard

Signal conditioning of multiple sense elements is shown for providing information to a system requiring high accuracy and robust fault coverage. A first signal conditioning ASIC () pre-conditions the sense element data and a second system control ASIC () mathematically solves predetermined compensation relations based on the output of ASIC () and stored compensation data to fully condition the sensor output signal(s). The sense elements () are each formed by two half bridges whose inputs are pre-conditioned by separate, identical signal conditioning paths to provide highly accurate sense and diagnostic information.

Variable condition responsive sense system and method

A multi-channel pressure sensor module () for integration in a hydraulic/electrical control unit of a vehicular braking system is shown. A body or manifold () mounts a plurality of strain gauge sense element assemblies () each having a port for connection to a fluid pressure source to be monitored. An electronic module assembly () has a contact printed circuit board () and a sense element printed circuit board () sandwiching a spacer/support member () and electrically coupled together by a flexible circuit board (). The spacer/support member () is formed with pockets () for receipt of discrete electronic components and to provide access to wire bond pads () and sense element openings (). First and second sets of guide posts () extend from the spacer/support member for alignment of the circuit boards as well as the electronic module assembly on the base. A cover () is received on the base over the electronic module assembly and provides access to contact pads of the contact printed circuit board through a shroud ().

Multi-channel pressure sensing apparatus

An ASIC ( ) conditions two independent outputs (VINM, VINP) of a full Wheatstone piezoresistive bridge ( ) in separate conditioning paths. Each path is provided with a bridge supply voltage (VHB , VHB ) which can serve as a temperature related input signal to respective offset and gain compensation control circuits. The half bridge outputs are inputted to respective amplifiers (U , U ) along with a selected percentage of the temperature dependent bridge supply voltage. The outputs of the amplifiers provide a signal proportional to respective half bridge output voltage. In one embodiment, the output of the amplifier (U ) in one conditioning path of one half bridge is connected to the input of an amplifier (U ) in the other conditioning path to provide a signal in the one path proportional to the Wheatstone bridge differential output voltage and in the other path a signal proportional to the Wheatstone half bridge output voltage. In another embodiment, the temperature dependent bridge supply voltage is multiplexed for a selected time upon power-up to an amplifier (U ) which normally receives an input from one of the bridge outputs.

Low cost asic architecture for safety critical applications monitoring an applied stimulus

A port fitting ( ) is formed with a closed, pedestal end forming a diaphragm ( ) on which a strain gauge sensor is mounted. A support member ( ) is received on the pedestal end and is formed with a flat end wall ( ) having an aperture ( ) aligned with the sensor. A circuit assembly ( ) is bonded to the flat end wall and the sensor wire bonded to the electronic circuit. A cover member ( ) placed on the support member, is provided with a cavity for a metal shield member ( ) fitted inside the cover member before assembly. The shield member is formed with spring members ( ) extending outside the perimeter of the cover member. The cover member is formed with circular cavities ( ) extending in an axial direction to provide seating for contact spring members ( ), making electronic contact to the sensor electronics and protruding beyond the body of the cover member. The cover member is also fitted with a circular elastomer gasket member ( ), providing an environmental seal. A connector member ( ), comprised of an integrally formed metal housing member ( ) and bent terminals ( ), is then placed over the cover member in such a manner that the terminals are aligned with the spring contact members, making electrical contact with the spring members. The bottom portion ( ) of the metal housing is welded to a support flange ( ) of the port fitting while its top portion ( ) places a selected load on the elastomer seal member seated on the cover member of the transducer.

Hermetic pressure transducer

An application specific integrated circuit or ASIC (MSC) is connected to a plurality of bridge type sense elements ( ) for analog multiplexing ( ) the outputs from a selected sense element to a common signal conditioning path ( ). The bridge type sense elements are biased through an electronically programmable resistor ( ) to derive a temperature signal. The signal conditioning path provides electronically programmable correction for offset and gain proportional to the sensed condition, e.g., fluid pressure. Complete sensor characterization data provided at the time of manufacture is stored in non-volatile memory ( ) which is downloaded to a host controller ( ) on command. The ASIC also includes diagnostic test bridges (BR BR ) for diagnosing ASIC faults and a signal diagnostic path ( ) for diagnosing sense element and sense element connection faults. Characterization data downloaded to the host controller enables the controller to mathematically correct remaining temperature, condition (e.g., pressure) and diagnostic signal errors,

Condition responsive sense system and method

A full Wheatstone bridge sensor has conditioning electronics of an ASIC connected thereto. Two independently controlled diagnostic switches (S1, S2) in the ASIC are commonly connected to one of the bridge output nodes. The first diagnostic switch connects first resistor between the bridge output node and bridge supply voltage and the second diagnostic switch connects a second resistor between the bridge output and bridge ground. The first diagnostic switch closes during a first diagnostic waveform phase and opens during all other phases of operation. The second diagnostic switch closes during a second and third waveform phase and opens during all other phases of operation. The diagnostic waveforms are used to test major signal conditioning and fault reporting paths of the ASIC.

Method and apparatus for fault detection in a resistive bridge sensor

Detection of excessive negative offset of a condition responsive sensor such as a pressure responsive full Wheatstone bridge element ( ) and circuitry associated therewith is obtained by taking the sensor's output signal, preferably after the signal has been compensated for both gain and offset and comparing (Q ) the signal (V ) with a reference voltage (V ) selected to reflect an unobtainable stimulus input condition and driving the compensated signal to a fault level when the compensated signal exceeds the reference voltage.

Method and apparatus for providing detection of excessive negative offset of a sensor

A port fitting ( ) is formed with a closed, pedestal end forming a diaphragm ( ) on which a strain gauge sensor ( ) is mounted. A support member ( ) is received on the pedestal end and is formed with a flat end wall ( ) having an aperture ( ) aligned with the sensor. A portion of a flexible circuit assembly ( ) is bonded to the flat end wall. An electronics chamber is formed in a connector ( ) which is inverted and maintained at a selected height adjacent to the flat end wall of the support member to facilitate soldering of the flexible circuit to terminals ( ) in the connector and electronic components to the flexible circuit. The port fitting, when assembled to the support member, is also maintained at the selected height adjacent to the inverted connector to facilitate wire bonding the sensor to the bonded portion of the flexible circuit. The connector ( ) is then turned over, bending the flexible circuit assembly ( ) into a generally U-configuration, and attached to the support member. In one embodiment, as a last step in assembling the transducer, a tubular outer housing ( ) is fitted over the connector/support member sub-assembly and its bottom portion is welded to a support flange of the port fitting while its top portion places a selected load on an O-ring ( ) received about the connector as well as internal components of the transducer.

An in-range fault detection system for a full wheatstone bridge element ( ) having piezoresistive elements (R , R , R , R ) has bridge outputs (INP, INM) connected to measuring means in the form of a first circuit portion ( ) to provide a common mode voltage (V ). A second circuit portion ( ) is used to provide a centering voltage (C*V ) equal to the common mode voltage at the time of sensor calibration and a third circuit portion ( ) is used to provide a small window voltage (W*V ) which is a fraction of bridge voltage. The value (W*V ) is subtracted from (C*V ) at a first summing circuit (SUM ) and added to (C*V ) at a second summing circuit (SUM ) and the results are each compared to the common mode voltage by comparators (Q , Q ) which are then determined to be within or without a window of valid values by an OR gate (Q ).

Method and apparatus for in-range fault detection of condition responsive sensor

A solid state power controller for switching power on and off to an electrical load which also serves as a circuit protection device protecting the load and/or the wire connected between the load output terminal of the controller and ground from thermal damage due to current overload is shown. Upon current overload the controller interrupts current to the load in a time inversely proportional to the square of the magnitude of the overload. The controller also limits the load current to a selected maximum level by controlling the drain-source resistance of power MOSFETs (PS1-7) used for switching power. A secondary interrupt is provided in the event that the junction temperature of the MOSFETs has risen to a selected maximum level. A thermal memory feature is included for both interrupt signals. The controller is controlled by a single on/off input line (COMMAND) and provides both a status (STATUS) and trip (TRIP) output line. The status can be configured to monitor load voltage or load current flow. The controller also can be configured to default to either an on or off state in the event the input line is disconnected. The controller is made so that it is externally programmable by providing selected external connection points (MPA, DTA, CLA1, CLA2) and choosing values of certain components (R.sub.cl1i, R.sub.cl2i, R.sub.ii, C.sub.ii, R.sub.mpi, C.sub.mpi) contained within the sealed controller package which results in a selected default condition.

Externally programmable solid state power controller with power switch

A variable differential transformer system (10), both linear and rotary (L/RVDT) includes a primary coil (12) drive by a primary drive (20) having a triangle wave generator whose frequency is set by an external frequency control (R.sub.osc and C.sub.osc) which includes compensation for gain temperature error. Secondary coils (14, 16) have a common connection for balanced loading with an input stage arrangement (R7, R8, R9, R10) providing low common mode range and a way to differentiate between normal operation and coil faults detected by a fault detection network (28). Synchronous demodulation (22) extracts both magnitude and direction from the secondary coil signals. Electronic calibration (24) is shown which compensates for sensor offset and gain. Sensor offset calibration is accomplished by adding a percentage of the synchronous demodulation reference wave form to the differential secondary signal. A filter network (26) averages the synchronous demodulated signal in order to extract the DC component of the wave form. A dual function output amplifier (30) provides a means of reporting the analog sensor output and the occurrence of a sensing element fault with sufficient drive current to interface with external loads. A variable rotary core assembly (18) and a variable linear core assembly (18') are shown which allow axial adjustment of the core relative to the coils to provide offset temperature error compensation.

Variable differential transformer system and method providing improved

A variable differential transformer system (10), both linear and rotary (L/RVDT) includes a primary coil (12) drive by a primary drive (20) having a triangle wave generator whose frequency is set by an external frequency control (R.sub.osc and C.sub.osc) which provides compensation for gain temperature error. Secondary coils (14, 16) have a common connection for balanced loading with an input stage arrangement (R7, R8, R9, R10) providing low common mode range and a way to differentiate between normal operation and coil faults detected by a fault detection network (28). Synchronous demodulation (22) extracts both magnitude and direction from the secondary coil signals. Electronic calibration (24) compensates for sensor offset and adjust circuit gain by adding a percentage of the synchronous demodulation reference waveform to the secondary differential voltage. A filter network (26) averages the synchronous demodulated signal in order to extract the DC component of the waveform which is amplified (30) to provide drive current to interface with external loads. A variable rotary core assembly (18) and a variable linear core assembly (18') are shown which allow axial adjustment of the core relative to the coils to provide balancing of the out-of-phase component of the secondary voltage waveform to provide offset temperature error compensation without significantly affecting the in-phase component of the secondary waveform.

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Rehoboth, MA, United States of America

Thomas Richard Maher