Abstract: A position detecting system detects and responds to the movement of a target through a sensing domain area of a plane. The movement causes the amount of the target that lies within a sensing domain area to change. A portion of the target always lies within at least one of the sensing domain areas of the plane.

Abstract: A position detecting system detects and responds to the movement of a target through a sensing domain area of a plane. The movement causes the amount of the target that lies within a sensing domain area to change. A portion of the target always lies within at least one of the sensing domain areas of the plane.

Abstract: A position detecting system detects and responds to the movement of a target through a sensing domain area of a plane. The movement causes the amount of the target that lies within a sensing domain area to change. A portion of the target always lies within at least one of the sensing domain areas of the plane.

Abstract: A position detecting system detects and responds to the movement of a target through a sensing domain area of a plane. The movement causes the amount of the target that lies within a sensing domain area to change. A portion of the target always lies within at least one of the sensing domain areas of the plane.

Abstract: A method for calibrating an analog-to-digital converter includes sampling an analog input signal and generating input samples, reversing the polarity of at least one input sample, averaging the digital output codes associated with a first pair of input samples where the first pair of input samples has opposite polarities, and generating an offset correction value being the average of the digital output codes associated with the first pair of input samples. In another embodiment, a method for calibrating an ADC includes sampling the analog input signal and generating input samples, introducing an incremental value to modify the magnitude of at least one input sample, computing an actual gain value using the digital output codes associated with a first input sample and a second input sample having the modified magnitude, and generating a gain correction value being the ratio of an ideal gain of the ADC to the actual gain.

Abstract: A method for removing component mismatch errors for a system parameter being set by a ratio of two or more physical, electrical components (“components”) of the same kind on an integrated circuit including providing an array of component units having the same component value, determining the actual component values of each component unit in the array, selecting component units based on the actual component values to form pairs of component units where the pairs have approximately the same total component values, ordering the component unit pairs, assigning alternate component unit pairs to be associated with each of the two or more components, rotating at a first frequency the assignment of the component unit pairs. At each rotation, the component unit pairs to be associated with each component are shifted so that each component unit pair is associated with a different one of the two or more components in turn.

Abstract: A method and apparatus improves the accuracy of temperature measurements by sampling measurements from a remote sensor, where currents of different current densities are applied to the remote sensor in a time-interleaved fashion. The remote sensor includes at least one PN junction that produces a voltage corresponding to the applied current at each instance of time, and related to the temperature of the remote sensor. By applying time-interleaved current densities to the remote sensor, adverse effects from temperature variations during the measurement are minimized. Sequences of current biases having differing current densities in a forward order are applied to the remote sensor, followed by the same sequence being applied to the remote sensor in a reverse order. Similarly, a random or pseudo-random sequence may be employed in a forward and reverse order. The application of forward and reverse sequences is utilized to minimize errors in the temperature measurement.

Abstract: A circuit is arranged to limit the rate of change in fan speed control signals. The control system includes a controller that produces a nonlinear (or piecewise linear approximation of a nonlinear function) fan speed control signal. The nonlinear fan speed control signal can reduce unnecessarily large changes in the fan speed and provide a greater degree of control at higher temperatures. Linear changes in the speed of a fan often result in audible noises that are undesirably distracting. Controlling the fan by using nonlinear exponential step sizes advantageously reduces the apparent fan noise by linearly varying the amount of fan noise in approximately equal percentages between each programmed fan speed. The step sizes are nonlinear with respect to temperature change and are linear with respect to fan noise.

Abstract: A circuit is arranged control the acceleration of a fan by limiting the rate of change in fan speed control signals. The control system includes an acceleration controller that low pass filters a target fan speed control signal. The low pass filtering signal minimizes abrupt changes in the fan speed. A sudden change in the speed of the fan often results in an audible noise that is undesirably distracting. Filtering the fan speed control signal advantageously slows the rate of the fan speed changes without having to change device drivers for controlling the fan.

Abstract: A data acquisition system for sampling a temperature signal from a temperature sensor includes: a programmable current source, a buffer with a constant offset, and an analog-to-digital converter (ADC). The programmable current source selectively provides bias currents to the temperature sensor, which produces response voltages in response to the applied bias current. The buffer receives the response voltages and produces buffered response voltages that include a constant offset. The ADC is arranged to produce digital codes in response to the buffered response voltages. The digital codes are used to determine a temperature associated with the temperature sensor. The buffer isolates the temperature sensor from the ADC such that loading effects are minimized and set-up times for the conversion are minimized.