Patent application number | Description | Published |
20110267018 | AC COUPLED HYSTERETIC PWM CONTROLLER - This document discusses, among other things, an apparatus and method for a hysteretic controller for an inductor based power converter. The hysteretic controller can include a coupling circuit configured to provide feedback information to a hysteretic comparator, the feedback information including a DC component of a feedback voltage and an AC component of the signal indicative of current flow through the inductor, wherein the feedback voltage is a scaled representation of load voltage. | 11-03-2011 |
20120092046 | LOW POWER POWER-ON-RESET (POR) CIRCUIT - In one general aspect, an apparatus can include a first voltage detect circuit configured to produce an output signal at a first power supply voltage, and configured to be in a non-monitoring state at a second power supply voltage greater than the first power supply voltage. The apparatus can include a second voltage detect circuit configured to change from a non-monitoring state to a monitoring state and configured to produce an output signal at a third power supply voltage between the first power supply voltage and the second power supply voltage. The apparatus can also include a combination circuit configured to produce a power-on-reset signal based on a logical combination of the output signal produced by the first voltage detect circuit and the output signal produced by the second voltage detect circuit. | 04-19-2012 |
20120092059 | LOW SUPPLY NOISE POWER STAGE ARRANGEMENT FOR A SWITCH REGULATOR - In a general aspect, an apparatus can include a first switch configured to be coupled to a power source and configured to switch in response to an edge of a control signal. The apparatus can include delay circuit can be configured to produce a delay signal that has an edge corresponding to the edge of the control signal, the edge of the delay signal being offset from the edge of the control signal. The apparatus can also include a second switch can be configured to be coupled to the power source in parallel with the first switch and configured to switch in response to the edge of the delay signal, the second switch having a size smaller than a size of the first switch. | 04-19-2012 |
20120134407 | ADAPTIVE EQUALIZATION WITH GROUP DELAY - Methods, apparatuses, and systems are presented for performing adaptive equalization involving receiving a signal originating from a channel associated with inter-symbol interference, filtering the signal using a filter having a plurality of adjustable tap weights to produce a filtered signal, and adaptively updating each of the plurality of adjustable tap weights to a new value to reduce effects of inter-symbol interference, wherein each of the plurality of adjustable tap weights is adaptively updated to take into account a constraint relating to a measure of error in the filtered signal and a constraint relating to group delay associated with the filter. Each of the plurality of adjustable tap weights may be adaptively updated to drive group delay associated with the filter toward a target group delay. | 05-31-2012 |
20130263665 | MEMS DEVICE FRONT-END CHARGE AMPLIFIER - This document discusses, among other things, apparatus and methods for a front-end charge amplifier. In certain examples, a front-end charge amplifier for a microelectromechanical system (MEMS) device can include a charge amplifier configured to couple to the MEMS device and to provide sense information of a proof mass of the MEMS device, a feedback circuit configured to receive the sense information and to provide feedback to an input of the charge amplifier, and wherein the charge amplifier includes a transfer function having a first pole at a first frequency, a second pole at a second frequency, and one zero at a third frequency. | 10-10-2013 |
20130268227 | MEMS DEVICE AUTOMATIC-GAIN CONTROL LOOP FOR MECHANICAL AMPLITUDE DRIVE - This document discusses, among other things, apparatus and methods for digital automatic gain control for driving a MEMS device, such as a proof mass. In an example, an apparatus can include a driver configured to oscillate a proof mass of a MEMS device, a charge-to-voltage (C2V) converter configured to provide oscillation information of the proof mass, an analog-to-digital converter (ADC) configured to provide a digital representation of the oscillation information, and a digital, automatic gain control circuit to provide oscillation amplitude error information using a comparison of the oscillation information to target amplitude information, and to provide a digital drive command signal using an amplified representation of the oscillation amplitude error information. | 10-10-2013 |
20130268228 | MEMS DEVICE QUADRATURE SHIFT CANCELLATION - This document discusses, among other things, apparatus and methods quadrature cancelation of sense information from a micro-electromechanical system (MEMS) device, such as a MEMS gyroscope. In certain examples, a quadrature correction apparatus can include a drive charge-to-voltage (C2V) converter configured to provide drive information of a proof mass of a MEMS gyroscope, a sense C2V converter configured to provide sense information of the proof mass, a phase-shift module configured to provide phase shift information of the drive information, a drive demodulator configured to receive the drive information and the phase shift information and to provide demodulated drive information, a sense demodulator configured to receive the sense information and the phase shift information and to provide demodulated sense information, and wherein the quadrature correction apparatus is configured to provide corrected sense information using the demodulated drive information and the demodulated sense information. | 10-10-2013 |
20130269413 | MEMS QUADRATURE CANCELLATION AND SIGNAL DEMODULATION - In certain examples, a quadrature cancellation apparatus can include a drive charge amplifier configured to couple to a proof mass of a MEMS device and to provide oscillation motion information, a first sense charge amplifier configured to couple to the proof mass and to provide first sense information of a first movement of the MEMS device, a first programmable amplifier configured to receive the oscillation motion information and provide amplified oscillation motion information, a first summer configured to cancel quadrature error of the first sense information using the first sense information and the amplified oscillation motion information to provide quadrature-corrected first sense information, a phase shifter configured to receive the oscillation motion information and to provide carrier information, and a first multiplier configured to provide demodulated first sense information using the quadrature-corrected first sense information and the carrier information. | 10-17-2013 |
20130271228 | MICRO-ELECTRO-MECHANICAL-SYSTEM (MEMS) DRIVER - In an example, a driver for a micro-electro-mechanical-system (MEMS) device can include a first input configured to receive a first command signal including an oscillatory command signal, a second input configured to receive a second command signal including a bias command signal, and an amplifier configured to receive a high voltage supply, to provide, to the MEMS device, a closed-loop output signal responsive to both the first command signal and the second command signal in a first state, and to provide an open loop output signal configured to substantially span a voltage range of the high voltage supply in a second state. | 10-17-2013 |