Invensense, Inc.

Zerog Wireless, Inc.

Other

Microchip Technology Inc.

Stanley Wang

Thomas H Lee

Derek Keith Shaeffer

Bendik Kleveland

A round-robin sensing device is disclosed. The round-robin sensing device comprises a MEMS device, wherein the MEMS device includes first and second sense electrodes. The round-robin sensing device also comprises a multiplexer coupled to the first and second sense electrodes, at least one sense amplifier coupled to the multiplexer, a demodulator coupled to the at least one sense amplifier, and an integrate and dump circuit coupled to the demodulator. Finally, the round-robin sensing device comprises an analog-to-digital converter (ADC) coupled to the de-multiplexer, wherein the multiplexer, the at least one sense amplifier and the demodulator provide a continuous time sense path during amplification that is resettable and wherein the integrate and dump circuit and the ADC provide a discrete time processing path.

Round robin sensing device and method of use

A gyroscope system comprises a MEMS gyroscope coupled to a drive system and a sense system. The drive system maintains the MEMS gyroscope in a state of oscillation and the sense system for receiving, amplifying, and demodulating an output signal of the MEMS gyroscope that is indicative of the rate of rotation. The gyroscope system further includes a phase-locked look (PLL) which receives a reference clock (REFCLK) from the drive system and produces a system clock (CLK). Finally, the gyroscope system includes a controller operating on the system clock sets an operating state of the drive system and the sense system and also controls a state of the PLL. One or more system state variables are maintained in a substantially fixed state during a protect mode thereby enabling rapid transitions between a low-power mode and a normal operating mode of the gyroscope system.

Duty-cycled gyroscope

A pressure sensor is provided which produces a measurement of the displacement and a measurement of a natural frequency of the diaphragm which are then combined to produce a compensated measurement of the displacement of the diaphragm, thereby substantially eliminating the dependence of the compensated displacement measurement on strain.

Pressure sensor stabilization

Round-robin sensing device and method of use

A calibration circuit () and method () for calibrating the bias current of a VCO () to minimize phase noise. The calibration circuit () monitors the average voltage at the common-mode node of the VCO () while varying the bias current over a predetermined range. The calibration circuit () identifies the bias current associated with the minimum average common-mode voltage and utilizes this bias current for calibrating the biasing transistor of the VCO ().

Calibration of voltage controlled oscillators

A frequency synthesizer () including an edge-detection circuit () for disabling elements of the frequency synthesizer () prior to start-up. The edge-detection circuit detects a transition edge of a reference-clock signal (ref_clk) of the frequency synthesizer () and enables elements of the frequency synthesizer () upon the detection of the transition edge.

Edge alignment for frequency synthesizers

A calibration circuit () for calibrating a frequency synthesizer () having a voltage-controlled oscillator (VCO) () with a plurality of switched-capacitor arrays (CA-CAn). The calibration circuit () counts a predetermined number of periods of the reference-clock signal (ref_clk) and divide-clock signal (div_clk) of the frequency synthesizer using a fast clock signal (fastclk). The fast-clock signal (fastclk) has a frequency greater than either the reference-clock signal (ref_clk) or the divide-clock signal (div_clk), enabling significantly faster calibration of the frequency synthesizer () than would be possible using the reference-clock signal (ref_clk). The calibration circuit () compares the count of the periods of the reference-clock signal (ref_clk) and the divide-clock signal (div_clk) and varies the tank signal of the VCO (VCO_tank_setting) until the count of the periods is substantially equal.

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Cupertino, CA, United States of America

Stanley Wang