Abstract: A dual backplate MEMS microphone system including a flexible diaphragm sandwiched between two single-crystal silicon backplates may be formed by fabricating each backplate in a separate wafer, and then transferring one backplate from its wafer to the other wafer, to form two separate capacitors with the diaphragm.

Abstract: A method and a corresponding device for calibrating an interleaved analog-to-digital converter (ADC) involve injecting a pulsed, substantially-random signal into a plurality of channels in the ADC. After the substantially-random signal is injected, a gain correlation value is determined for each channel, which value indicates a degree of correlation between the injected substantially-random signal and an output of the respective channel. The gain correlation values are then compared to determine a degree of mismatch between the channels. At least one of the channels is calibrated as a function of the determined degree of mismatch.

Abstract: DC-DC voltage converter systems are provided in which a switching voltage converter is arranged with an inductor to switch first and second currents with duty cycles D and D? determined by an error voltage Verr to thereby maintain an output voltage Vout. A transconductance amplifier having an amplifier output provides the error voltage Verr in response to the output voltage and a reference voltage Vref. A ripple current Irpl is provided to the amplifier output in response to the difference between the error voltage Verr and a clamp voltage Vclmp. Finally, a current comparator generates a skip signal to turn off the first and second currents in response to a selected threshold of the ripple current. In this process, the ripple current Irpl substantially clamps the error voltage Verr to the clamp voltage Vclmp.

Abstract: An apparatus and method for determining characterizing attributes of an actuator is provided. An actuator may be moved to a maximum capacitance position. At the maximum capacitance position, an initial measurement of the actuator capacitance is made. The actuator is moved a predetermined increment toward a first extreme position, and the actuator capacitance is again measured. If the capacitance changed by a threshold amount, the signal preceding the signal that caused the actuator to move is recorded as an approximate response curve end point, or the first extreme position. The actuator is again moved a predetermined increment toward a second extreme position. After each move, the capacitance is measured. If it is determined the capacitance did change by a threshold amount from the previously measured capacitance, the signal related to the previously measured capacitance is recorded as an approximate response curve end point, or the second extreme position.

Abstract: Apparatus and methods for electronic circuit protection are disclosed. In one embodiment, an actively-controlled protection circuit includes a detector, a timer, a current source and a latch. The detector is configured to generate a detection signal when the detector determines that a transient signal satisfies a first signaling condition. The timer is configured to receive the detection signal, and to generate a current control signal. The current control signal is provided to a current source, which produces a trigger current at least partly in response to the control signal. The trigger current is provided to a node of the latch, thereby enhancing the conductivity modulation of the latch and selectively controlling the activation voltage of the latch.

Abstract: The invention is directed to a digital isolation system including an isolation barrier, a transmitter circuit receiving an input signal and transmitting a positive pulse upon detecting a first type of edge in the input signal and transmitting a negative pulse upon receipt of a second type of edge in the input signal and a receiver circuit receiving the transmitted signals, removing noise in the received signal and reconstructing the input signal using a differential comparator.

Abstract: An adaptive phase offset controller for use with a switching power converter having first and second channels. The controller includes a discriminator which detects a ‘critical condition’ in which a switching signal for the first channel transitions during a critical time interval so as to give rise to crosstalk that can corrupt the operation of the second channel's control circuit. When the discriminator detects a critical condition, a phase offset circuit offsets the phase of the first channel's switching signals, such that subsequent transitions occur outside of the critical time interval. A second discriminator and phase offset circuit are preferably employed to detect critical conditions which can give rise to crosstalk that can corrupt the operation of the first channel's control circuit.

Abstract: A negative resistance device for a multiphase oscillator is disclosed. The negative resistance device is coupled to taps of the multiphase oscillator so that it injects no energy into the oscillator when the oscillator is most sensitive to noise, thereby decreasing the phase noise of the oscillator. The negative resistance device also guarantees the direction of movement of a traveling wave past the taps of the multiphase oscillator.

Abstract: Embodiments of the present invention provide a sample and hold amplifier that provides a preamplifier with a multi-stage zeroing architecture. The multi-stage architecture reduces effects of parasitic capacitance exponentially over prior attempts, which yields increased accuracy.

Abstract: Microelectromechanical systems (MEMS) microphone devices and methods for packaging the same include a package housing, an interior lid, and an integrated MEMS microphone die. The package housing includes a sound port therethrough for communicating sound from outside the package housing to an interior of the package housing. The interior lid is mounted to an interior surface of the package housing to define an interior lid cavity, and includes a back volume port therethrough. The MEMS microphone die is mounted on the interior lid over the back volume port, and includes a movable membrane. The back volume port is configured to allow the interior lid cavity and the MEMS movable membrane to communicate, thereby increasing the back volume of the MEMS microphone die and enhancing the sound performance of the packaged MEMS microphone device.

Abstract: A switching power supply control system may include logic to generate a greater number of second switching control signals in response to a first number of original switching control signals. For example, the logic may increase the number of phases that may be controlled by an existing switching power supply controller. The logic may be configured to steer feedback signals from the increased number of phases back to original feedback inputs on the controller.

Abstract: A circuit includes a signal processing circuit for accepting an input and for generating a set of outputs. The input is provided in an input range that has a set of representative values, and each output represents a measure of an association of the input with one or more of the representative values. The signal processing circuit includes a group of output sections, each output section being responsive to the input of the signal processing circuit. Each output section includes one or more sigmoid generators. Each sigmoid generator is responsive to an input of the output section to generate an output that represents a sigmoid function of the input of the output section. Each output section also includes a circuitry for combining the outputs of the one or more sigmoid generators to form one of the set of outputs of the signal processing circuit. An input transformation circuit is coupled to the plurality of output sections.

Abstract: Apparatus and methods of manufacture for a wideband RF mixer are provided. The RF mixer includes an input, an LO input, and an output. A variable impedance tuner is disposed in an input signal path between the input port and the RF mixer, and a variable impedance tuner is disposed in an output signal path between the output and the RF mixer. The impedances of the variable impedance tuners are controllable for a particular frequency of operation with one or more digital or analog control signals.

Abstract: Embodiments of the present invention provide an integrated circuit system including a first active layer fabricated on a front side of a semiconductor die and a second pre-fabricated layer on a back side of the semiconductor die and having electrical components embodied therein, wherein the electrical components include at least one discrete passive component. The integrated circuit system also includes at least one electrical path coupling the first active layer and the second pre-fabricated layer.

Abstract: Embodiments of the present invention may provide a system with a first and second circuit system separated by an electrical isolation barrier but provided in communication by at least one isolator device that bridges the isolation barrier. The first circuit system may include a communication system to transmit data across a common isolator device as a series of pulses, and the second circuit system may receive the series of pulses corresponding to the data. The second circuit system may include a detector coupled to the common isolator device to detect the received pulses, a oneshot to frame the received pulse(s), and a controller to reconstruct the data based on accumulated framed pulse(s). Therefore, noise induced spurious pulses outside the oneshot intervals may be ignored by the second circuit system providing improved noise immunity.

Abstract: Embodiments of the present invention may provide an improved apparatus and method for reducing distortion in analog circuits. A circuit in accordance with the present invention may include a main path comprising an analog circuit with an input impedance, a source impedance representing the impedance of an input network driving the analog circuit, and a cancellation path. The cancellation path may be in parallel to the main path and may generate a cancelling non-linear current to substantially cancel a non-linear current drawn to the input impedance, resulting in a decrease of non-liner current flowing through the source impedance.

Abstract: An isolator system is disclosed in which a pair of circuit systems is separated by an isolation barrier but engage in mutual communication by an isolator device that bridges the isolation barrier. A first circuit system may include a measurement system generating measurement data and status monitor generating status data. The first circuit system also may include a communication system that multiplexes the measurement data and the status data for transmission across a common isolator device. In this manner, the number of isolator devices may be reduced over conventional designs.

Abstract: Techniques to reduce correlated errors in a multi-channel sampling system. A plurality of clock signals may be generated from a master clock signal, each with edges offset from each other. The offset clock signals may be distributed to a plurality of sampling devices. Each sampling device may capture a respective input signal according to its offset clock. In this manner, the sampling units may sample their inputs signals over a distributed window of time rather than sampling in response to a common clock edge. By distributing the switching operations performed by the sampling units, noise effects are likely to be reduced.

Abstract: A USB-based isolator system conveys USB signals between a pair of galvanically isolated circuit systems and supports controlled enumeration by a downstream device on upstream USB signal lines. The isolator system provides a multi-mode voltage regulator to support multiple voltage supply configurations. The isolator system further provides control systems for each of the isolated circuit systems and provides robust control in a variety of start up conditions. Additionally, the isolator system includes refresh timers and watchdog mechanisms to support persistent operation but manage possible communication errors that can arise between the isolated circuit systems.

Abstract: Metal oxide semiconductor (MOS) protection circuits and methods of forming the same are disclosed. In one embodiment, an integrated circuit includes a pad, a p-type MOS (PMOS) transistor, and first and second n-type MOS (NMOS) transistors. The first NMOS transistor includes a drain, a source and a gate electrically connected to the pad, a first supply voltage, and a drain of the PMOS transistor, respectively. The second NMOS transistor includes a gate, a drain, and a source electrically connected to a bias node, a second supply voltage, and a source of the PMOS transistor, respectively. The source of the second NMOS transistor is further electrically connected to a body of the PMOS transistor so as to prevent a current flowing from the drain of the PMOS transistor to the second supply voltage through the body of PMOS transistor when a transient signal event is received on the pad.