Texas Instruments Corporation

Timothy John Legat

David John Baldwin

Thomas Richard Maher

Alexander Noam Teutsch

Sanmukh Makan Patel

Ross Elliot Teggatz

Ross Eliot Teggatz

Joseph A Devore

Timothy Patrick Pauletti

William E Grose

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 reverse battery protection circuits that provides an integrated reverse battery condition solution for protection of external NMOS switches during the reverse battery condition is disclosed herein. This reverse battery protection circuit minimizes power consumption during a reverse battery event wherein there is no need for mechanical adjustments such as heat sinking and clamping to extract the heat away from the silicon and not destroy the device. Specifically, the reverse battery protection circuit includes a push-pull gate drive circuit coupled between the first and second power supply rail. A protection subcircuit portion connects between a first output node and the second power supply rail to turn the external FET 'on' during the reverse battery condition. In particular, the protection subcircuit portion connects to the external FET device and includes a p-channel device connected between a second output node that biases the external FET device and a first diode. A resistor connects between a first output node of the reverse battery protection circuit to provide a voltage drop between the drain terminal and the gate of the p-channel device. A second diode connects between the gate and the source of the p-channel device. In addition, a clamping circuit connects between the second output node and the third output node to provide clamping in the instance where the voltage at the second output node momentarily rises too high.

Integrated reverse battery protection circuit for an external MOSFET switch

A control circuit ( ) for a switch mode power converter having precise control of amplitude and frequency that does not exhibit overshoot error nor undershoot error during a fast charge cycle nor a fast discharge cycle, respectively. In a first embodiment, the control circuit ( ) does not exhibit undershoot error during a fast discharge cycle. The control circuit ( ) comprises an oscillator ( ) for providing a periodic carrier signal comprising a sawtooth wave output signal (V ). The oscillator ( ) includes a capacitor (C ) charged and discharged to the power supply voltage (V ) to provide the sawtooth wave output signal (V ). In addition, the oscillator ( ) includes a switching circuit ( ) coupled to the reference voltage level (V ). The control circuit ( ) further includes a gain circuit ( ) having a reference voltage input (V ), voltage input (V ) and an output (Out). The reference voltage input (V ) receives the reference voltage(V ). The voltage input (V ) connects to the capacitor (C ). The output (Out) of the gain circuit ( ) connects to the switching circuit ( ) to provide feedback proportional to the analog error signal related to the difference between the sawtooth wave output signal (V ) and the predetermined reference voltage level (V ).

Pulse width modulation regulator control circuit having precise frequency and amplitude control

A controlled area network (CAN) driver provides improved symmetry between its differential output signals CAN-H and CAN-L, and provides protection for its low voltage devices from voltage transients occurring on its output lines. A plurality of CAN drivers,are serially interconnected to form a driver system, wherein each downstream driver stage receives a time-delayed form of the digital input signal TxD, each stage providing a time-delayed contribution to the differential output signals of the overall driver system.

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McKinney, TX, United States of America

Timothy John Legat