Cypress Semiconductor Corporation

Infineon Technologies Ag

Infineon Technologies Austria Ag

Kofi Makinwa

Paul M Walsh

Dermot MacSweeney

Mario Motz

Dennis Raymond Seguine

Daniel O'Keeffe

Çagri Gürleyük

Amirhossein Jouyaeian

Said Hussaini

Hui Jiang

Matheus Pimenta

Dieter Draxelmayr

Kaveh Hosseini

Dermot Macsweeney

Saleh Heidary Shalmany

Rishi Raghav Bacchu

Qinwen Fan

Front-end circuits that combine inductive and capacitive sensing are described. In one embodiment, an apparatus includes a plurality of inductive elements, an inductive measurement circuit, and a frequency divider circuit. The inductive measurement circuit is to output a first signal with a first frequency. The first signal is associated with an inductance change of one of the inductive elements. A feedback circuit can maintain the sinusoidal operation of the first signal. The frequency divider circuit can generate a second signal with a second frequency that is lower than the first frequency.

High performance inductive sensing all digital phase locked loop

An asynchronous capacitance-to-digital conversion is described that allows for very low-power operation when during inactive periods (when no conductive object is in contact or proximity to the sensing electrodes). Asynchronous operation of a capacitance-to-digital converter (CDC) provides for capacitance-to-digital conversion without the use of system resources and more power intensive circuit elements.

Nano-power capacitance-to-digital converter

The described techniques address issues associated with hybrid current or magnetic field sensors used to detect both low- and high-frequency magnetic field components. The hybrid sensor implements a DC component rejection path in the high-frequency magnetic field component path. Both digital and analog implementations are provided, each functioning to generate a DC component cancellation signal to at least partially cancel a DC component of a current signal generated via the high-frequency magnetic field component path. The hybrid sensor provides a high-bandwidth, high-accuracy, and low DC offset hybrid current solution that also eliminates the need for DC decoupling capacitors in the high-frequency path. A modification is also described for implementing a Sigma-Delta (ΣΔ) quantization noise reduction path to reduce the quantization noise and to improve accuracy.

Hybrid high-bandwidth magnetic field sensor

The described techniques address issues associated with hybrid current or magnetic field sensors used to detect both low- and high-frequency magnetic field components. The hybrid sensor implements a DC component rejection path in the high-frequency magnetic field component path. Both digital and analog implementations are provided, each functioning to generate a DC component cancellation signal to at least partially cancel a DC component of a current signal generated via the high-frequency magnetic field component path. The hybrid sensor provides a high-bandwidth, high-accuracy, and low DC offset hybrid current solution that also eliminates the need for DC decoupling capacitors in the high-frequency path. A modification is also described for implementing a Sigma-Delta (&#x3a3;&#x394;) quantization noise reduction path to reduce the quantization noise and to improve accuracy.

The present disclosure relates to a magnetic field sensor circuit including at least one coil for measuring a magnetic field, a first stage amplifier circuit coupled to the coil and having a first transfer function with a pole at a first frequency, and a second stage amplifier circuit coupled to an output of the first stage amplifier circuit and having a second transfer function with a zero at the first frequency. In some embodiments, a temperature dependent frequency drift of the pole of the first transfer function corresponds to a temperature dependent frequency drift of the zero of the second transfer function.

Apparatuses and methods for electrical current sensing

One inductive sensor is configured to maintain a fixed frequency in a resonant circuit. One apparatus includes an inductance-to-digital converter (LDC). The LDC includes a digital filter to measure an inductance change of a sensor and convert the inductance change to a digital value. The LDC further includes a digital control loop to maintain a fixed frequency in the sensor. The sensor forms an oscillator in the digital control loop. An output of the digital control loop is representative of the inductance change of the sensor.

An asynchronous capacitance-to-digital converter (CDC) is described that allows for very low-power operation when during inactive periods (when no conductive object is in contact or proximity to the sensing electrodes). Asynchronous operation of the CDC provides for capacitance-to-digital conversion without the use of system resources and more power intensive circuit elements.

In one embodiment, a shunt resistor is provided, comprising two terminals, a semiconductor substrate embodying at least one temperature sensor comprising at least a temperature sensitive element comprising at least one pn-junction, and at least two metal layers above the semiconductor substrate, at least the upper of the metal layer comprising a path that electrically connects the two terminals, whereby the temperature sensor is below and within the periphery of the upper metal layer.

Metal shunt resistor

A circuit, system, and method for measuring capacitance are described. A current may be received at an input of a conversion circuit. The current may be converted to a voltage signal which may be used to create a negative feedback current to the input of the conversion circuit and which may be demodulated digitally to provide a static digital output representative of a capacitance.

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San Jose, CA, United States of America

Kofi Makinwa