Semiconductor Components Industries, LLC

Alps Alpine Co., Ltd.

Ami Semiconductor, Inc.

David Willis

Jose Marcos Laraia

Matthew Austin Tyler

Justin Mark Gedge

Brent Quist

Mark R Whitaker

A system for generating an offset signal for a capacitive sensor includes a waveform generator configured to generate a waveform, an R-2R ladder circuit having a constant output resistance that is coupled to an output of the waveform generator and is configured to generate the offset signal based on the waveform, and an adjustable capacitor that is connected between an output of the R-2R ladder circuit and a reference voltage. The capacitive sensor includes one or more sensing electrodes coupled to the waveform generator through a capacitance and is configured to generate a sensed signal by sensing an object. The R-2R ladder circuit and the adjustable capacitor are configured to adjust amplitude and phase of the offset signal such that the amplitude and the phase of the offset signal respectively coincide with an amplitude and a phase of the sensed signal when the sensing electrodes do not sense the object.

Method to control amplitude and phase of a signal

A system for generating a control signal for a capacitive sensor includes a waveform generator configured to generate a digital waveform, a first sigma-delta modulator (SDM) configured to generate a first output corresponding to the control signal based on the digital waveform and first adjustment data and a second SDM configured to generate a second output corresponding to an offset signal based on the digital waveform and second adjustment data. The first SDM is configured to selectively adjust a phase and an amplitude of the control signal and the second SDM is configured to selectively adjust a phase and an amplitude of the offset signal.

Systems and methods to create offset signal using sinewave generator with programmable amplitude and phase

Pade Approximant function emulators are used to model the nonlinear offset and/or nonlinear sensitivity behaviors of a sensor relative to temperature sub-ranges and to produce temperature compensating corrections for both offset and sensitivity as desired. In order to avoid use of brute force division for generating the Pade Approximant function signals, in one set of embodiments, feedback is used to provide a corresponding effect. In order to minimize the number of coefficients that are to be resolved and stored, in one set of embodiments, first or higher order Pade Approximants with normalized denominators are used so that each function can be defined with just three coefficients. Embodiments that are more analog in nature or more digital in nature are disclosed. Methods for resolving the Pade Approximant coefficients and calibrating each sensor unit on a mass production basis are also disclosed.

Providing nonlinear temperature compensation for sensing means by use of pad&#xe9; approximant function emulators

A circuit that includes a controller and at least one control I/O pin. When the controller is placed into an initial state, the controller initializes the circuit into an initial operation mode. Depending on whether or not signal(s) satisfying predetermined criteria are applied to at least one of the control I/O pins, the controller will cause the circuit to enter one of two or more post-initial operation modes. Accordingly, by initializing the controller, and by controlling a signal on the control I/O pin(s), the operating mode of the circuit may be controlled. In one embodiment, a given control pin might be configurable to be both analog and digital, depending on the circuit's operation mode.

Initial decision-point circuit operation mode

Sensors and/or transducers can exhibit nonlinear response to temperature changes in terms of offset and also in terms of sensitivity to variations in a sensed physical attribute (pressure, strain, displacement, etc.). Pad&#xe9; Approximant function emulators are used to model the nonlinear offset and/or nonlinear sensitivity behaviors of a given sensing device relative to one or more temperature sub-ranges and to produce temperature compensating corrections for offset and/or sensitivity as may be desired.

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Murray, UT, United States of America

David Willis