Synaptics Corporation

Lsi Logic Corporation

Intrinsix Corporation

Integre Technologies, Inc.

Raum Technology Corp.

Clyde Washburn

Kirk Hargreaves

Eric Scott Bohannon

Jeffrey Alan Small

Imre Knausz

Joseph Kurth Reynolds

Adam L Schwartz

Eugene Michael Petilli

Brian Kirk Jadus

Robert J Bowman

Brian Mott

John Alvermann

A subsystem, system and method for sensing an input object relative to a sensing region of an ultrasound sensor device are disclosed herein. In one embodiment, a subsystem for sensing an input object relative to a sensing region of an ultrasound sensor device includes a circuit, a switch coupled to an output of the circuit, and an integrating capacitor coupled to the output of the circuit. The circuit has an input for receiving a resulting signal comprising positive and negative polarities, the resulting signal having effects indicative of the input object relative to the sensing region. The integrating capacitor is also coupled to a substantially constant voltage source and to the switch. The circuit is operable to output a rectified signal to the first integrating capacitor indicative of the input object relative to a sensing region.

Method and apparatus for sensing an input object relative to a sensing region of an ultrasound sensor device

An input device processing system comprises a sensor module that transmits a first transmitter signal with a transmitter electrode and receives a resulting signal with a receiver electrode. The first transmitter signal comprises a first transmitter frequency, and the resulting signal comprises effects corresponding to the first transmitter signal. A demodulation module demodulates the resulting signal to produce a first signal (e.g., an upper sideband signal) and a second signal (a lower sideband signal), selectably determines a first measurement of a change in capacitive coupling between the transmitter electrode and the receiver electrode based on at least one of the first and second signals, and determines positional information for an input object based on the first measurement.

Systems and methods for signaling and interference detection in sensor devices

Embodiments of the invention generally provide generating a ZTC current using resistors that may be integrated into an IC, even if these resistors vary with temperature. Specifically, instead of applying a bandgap voltage across a ZTC resistor, the bandgap voltage may be applied to a temperature-dependent resistor to generate a first current that varies (either proportionally or complementary) with temperature. Additionally, a second current may be generated which compensates for the temperature variance of the first current. If the two currents change in the same manner relative to temperature (i.e., the respective slopes of the currents are the same when the underlying circuit elements are exposed to the same temperature variations), the difference between the currents remains constant. Thus, subtracting the two currents, regardless of the current temperature, results in a ZTC current&#x2014;i.e., a current that is independent of temperature variations.

On-chip zero-temperature coefficient current generator

A processing system includes transmitter module, receiver module, and a demodulating module. The transmitter module comprises transmitter circuitry and is configured to simultaneously transmit a first transmitter signal with a first transmitter electrode and a second transmitter signal with a second transmitter electrode. The first transmitter signal includes a combination of a first heterodyne frequency and a carrier frequency. The second transmitter signal comprises a combination of a second heterodyne frequency and the carrier frequency. The receiver module comprise receiver circuitry and is configured to receive a first resulting signal with a receiver electrode, wherein the first resulting signal comprises first effects corresponding to the first transmitter signal and second effects corresponding to the second transmitter signal. The demodulating module is configured to demodulate the first resulting signal to produce a plurality of demodulation signals, wherein the demodulating module comprises a first mixer, a second mixer, a third mixer, a first filter, a second filter and a third filter. The first mixer includes a mixing frequency corresponding to the carrier frequency, the second mixer includes a mixing frequency corresponding to the first heterodyne frequency, and the third mixer includes a mixing frequency corresponding to the second heterodyne frequency.

System and method for signaling in sensor devices

A method and apparatus by which ATSC-receiver-compatible digital TV signals may be generated without most of the discrete and/or high-complexity components required by the ATSC specification, through the use of a precomputation of digital filter coefficients that consolidates multiple functions into a single step, and through the derivation of multiple required carrier frequencies using a single oscillator circuit. The resulting design meets all requirements of the ATSC specification, reducing significantly the cost of the necessary signal-processing functions, and in a manner compatible with the VLSI (very-large-scale-integrated) circuit technologies of the field.

Low-cost ATSC-receiver-compatible digital TV modulator

Disclosed are hybrid heterodyne transmitters and receivers for use in communications systems, or other systems, and the corresponding methods for hybrid heterodyne transmitting and receiving. A heterodyne receiver for converting a continuous time modulated signal to a discrete time digital baseband signal includes a sigma-delta modulator. The sigma-delta modulator is a sigma-delta analog-to-digital converter constructed and arranged to receive a modulated signal at an RF carrier frequency and provide a quantized output at a first intermediate frequency. The heterodyne receiver may also include a digital mixer constructed and arranged to receive a data stream quantized by the sigma-delta analog-to-digital converter and receive a signal at a second mixing frequency. The digital mixer then provides digital signals representative of a baseband signal suitable for digital signal processing.

Hybrid heterodyne transmitters and receivers

A bandgap reference voltage generating circuit includes a proportional to absolute temperature (PTAT) voltage generating means generating a PTAT voltage. A complementary to absolute temperature (CTAT) voltage generating means generates a CTAT voltage. A temperature coefficient determining means interconnects the PTAT voltage generating means and the CTAT voltage generating means.

Low-voltage bandgap voltage reference circuit

A circuit and method are disclosed herein for a crystal oscillator, wherein the Q of the resonant network is not reduced through the loading effects of the oscillator's resistive bias network. The oscillator is configured as an operational transconductance amplifier (OTA) coupled to the resonant network. The OTA creates a negative resistance, which compensates for energy lost to resistance within the resonant network, thereby sustaining oscillation at the resonant frequency. Instead of using bias resistors to set and maintain the operating point of the oscillator, another OTA (with a high output impedance) injects a current into the resonant network to bias the oscillator. Advantageously, this technique avoids the reduction in Q that occurs when bias resistors are connected across the high effective parallel resistance of the resonant crystal. The higher Q benefits frequency stability and phase jitter characteristics of the oscillator.

Crystal oscillator with minimized Q reduction

An oscillator provides output signals over a range of oscillating frequencies includes an resonant circuit, at least one active circuit device operatively coupled to the resonant circuit to supply energy to the resonant circuit, and at least one unidirectional device coupled to the active circuit device. The unidirectional device permits current to flow between the active circuit device and the resonant circuit when the active circuit device adds energy to the resonant circuit, and impedes a drain of energy from the resonant circuit due to increased output signal amplitude.

Oscillator having unidirectional current flow between resonant circuit and active devices

A deice maximizes the allowable granularity of adjustment of a bus driver line characteristics by compensating for temperature variations by selecting components that have an opposite and approximately equal thermal coefficient. In the first aspect, component parts may be made smaller because their tolerances need not be made so precise. In the second aspect, duplicating the circuitry with matching characteristics allows one circuit to be operational while the other circuit is tested or dormant. Switching between the two circuits is performed seamlessly with no interruption of device operation.

Method and apparatus for improving the tolerance of integrated resistors

A method and apparatus for controlling amplifier operating angle provides a corresponding increase in amplifier efficiency through a continual adjustment of operating angle from Class A, through Class AB, to Class B, an improved bandwidth in the output stage by preventing the output stage from reaching cutoff and the ability to adjust the high frequency content of the drive waveform to match that of the output stage thereby attaining the highest efficiency consistent with required distortion levels. A push-pull amplifier is coupled to a differential pushpull current drive source with out of phase drive signals and a preprocessing circuit with a first set of current sources which mirror one drive signal and a second set of current sources which mirror the other drive signal. The preprocessing circuit provides a full-wave rectified signal substantially representing the combined lower halves of the out of phase drive signals to be summed with the drive signals as composite input waveforms for the push-pull amplifier. The rectified signal is common-mode to both sides of the amplifier and gives instantaneous control of the bias point such that it is always just large enough to support the instantaneous amplitude of the signals as it adjusts the operating angle of the push-pull amplifier from Class A through Class B. A transformer is coupled to the output stages of the push-pull amplifier for summing the output signals.

Circuit and method for control of amplifier operating angle

A method and apparatus for mirroring currents in application specific integrated circuits provides higher current mirroring accuracy than previously obtainable with matched active devices by using small groups of resistors with local matching to create a summing node which represents the average voltage across the source resistors of the active output devices and by forming a reference resistor through the combination of resistors from the local resistor groups such that the reference resistor has properties which will largely cause cancellation of location gradients and initial value variation in the resistor groups. An error amplifier compares the voltage at the summing junction with the voltage across the reference resistor and adjusts its output voltage to drive the paralleled gates of each active mirror output device such that the summing junction and reference resistor voltages remain equal. The number of active devices forming an output array is typically an integer squared, and a local resistor group of three matched resistors is provided for each active mirror device. The error amplifier output voltage driving the gates of the active output devices causes the current flowing through each device to mirror the reference input current flowing through the reference resistor. The result is that the current flowing from the output array of active devices is closely equal to the integer squared times the reference input current flowing in the reference resistor.

Growing community of inventors

Victor, NY, United States of America

Clyde Washburn