Texas Instruments Corporation

James N Murdock

Per Torstein Roine

Danielle Griffith

Kunhee Cho

Rajat Chauhan

Bernhard Ruck

Baher S Haroun

Srinath Mathur Ramaswamy

Brian Paul Ginsburg

Vijay B Rentala

Eunyoung Seok

Ryan Alexander Smith

One example relates to a monitoring circuit that includes a capacitive digital-to-analog converter that receives a binary code, a reference voltage, a monitored voltage, and a ground reference, the capacitive digital-to-analog converter outputting an analog signal based on the binary code, the reference voltage, the monitored voltage, and the ground reference. The monitoring circuit further includes a comparator including a first input coupled to receive the analog signal and a second input coupled to the reference voltage, the comparator comparing the analog signal to the reference voltage and outputting a comparator signal based on the comparison. The monitoring circuit yet further includes a binary code generator that generates the binary code based on the comparator signal, the binary code approximating a magnitude of the monitored voltage.

Voltage monitor using a capacitive digital-to-analog converter

A reference generator provides a reference output voltage that is continuously available while providing certain efficiencies of a duty-cycled voltage regulator. The reference output voltage is generated by a sample-and-hold circuit that is coupled to a voltage regulator. On command, the sample-and-hold circuit samples a low dropout voltage regulator that may be referenced by a bandgap circuit. During hold periods of the sample-and-hold circuit, the voltage regulator, in particular the bandgap circuit, may be disabled in order to conserve power. A sample cycle by the sample-and-hold circuit may be triggered by a signal received from a configurable finite state machine. The reference generator is effectively duty cycled in a manner that conserves available battery power, while still providing a constant reference output that is always available. The reference generator is especially suited for low-power, battery operated applications.

Circuit and method for generating a reference voltage with a voltage regulator and a sample and hold circuit

A circuit includes an oscillator having a driver and a resonator. The driver receives a supply voltage at a supply input and provides a drive output to drive the resonator to generate an oscillator output signal. A power converter receives an input voltage and generates the supply voltage to the supply input of the driver. A temperature tracking device in the power converter controls the voltage level of the supply voltage to the supply input of the driver based on temperature such that the supply voltage varies inversely to the temperature of the circuit.

Temperature compensated oscillator driver

A circuit includes an oscillator having a driver and a resonator. The driver receives a supply voltage at a supply input and provides a drive output to drive the resonator to generate an oscillator output signal. A power converter receives an input voltage and generates the supply voltage to the supply input of the driver. The power converter varies the supply voltage based on an adjust command supplied to a command input of the power converter. A detector monitors a voltage level of the oscillator output signal. A controller sets the adjust command to the power converter to control the supply voltage to the supply input of the driver such that the voltage level of the oscillator output signal is set at or above a predetermined threshold voltage.

Set point adjuster for oscillator driver

A circuit includes a crystal oscillator to generate an output frequency for a circuit. A driving oscillator generates a startup signal having a driving frequency that is provided to activate the crystal oscillator. The driving frequency of the startup signal is varied over a range of frequencies that encompass the operating frequency of the crystal oscillator to facilitate startup of the crystal oscillator.

Driving crystal oscillator startup at above, below and operating frequency

An apparatus for emitting radiation is provided. The apparatus comprises an antenna formed on a substrate, and a high impedance surface (HIS). The HIS has a plurality of cells formed on the substrate that are arranged to form an array that substantially surrounds at least a portion of the antenna. Each cell generally includes a ground plane, first plate, second plate, and an interconnect. The ground plane is formed on the substrate, while the first plate (which is substantially rectangular) is formed over and coupled to the ground plane. The first plate for each cell is also arranged so as to form a first checkered pattern for the array. The second plate (which is substantially rectangular) is formed over and is substantially parallel to the first plate. The first and second plates are also substantially aligned with a central axis that extends generally perpendicular to the first and second plates hand have a interconnect formed therebetween. The second plate for each cell is also arranged so as to form a second checkered pattern for the array.

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James N Murdock