Abstract: A micro-machined switching system for equalizing an electrical property, such as charge due to parasitic capacitance formed at an input and an output of a micro-machined switching device. The micro-machined switching device may be a MEMS relay or a MEMS switch. In addition to the micro-machined switching device, the switching system also includes a balancing module for equalizing the electrical property between the input and the output of the micro-machined switching device. In certain embodiments, the balancing module includes a switch operable in a first state causing charge due to the parasitic capacitance on the input and the output of the micro-machined switching device to substantially balance. The switch is also operable in a second state wherein parasitic capacitance can separately accumulate at the input and the output of the micro-machined switching device.

Abstract: A DC to DC converter comprising: an inductor; a plurality of switches for controlling current flow in the inductor such that the inductor is connected to a supply in a first phase of operation such that the inductor receives energy from the supply, and such that the inductor is connected to an output in a second phase of operation in order to deliver energy to the output; and a controller arranged to monitor the current flow in the inductor at the end of the second phase of operation and to modify the relative duration of the second phase compared to the first phase as a function of the current flow.

Abstract: To compensate for changes in temperature, a pair of bipolar transistors is connected to a voltage divider and receives a differential voltage that varies with temperature. The voltage divider includes a set of resistors placed in parallel. The set of resistors has a resistance that changes with temperature. As the resistance changes with temperature, the differential voltage provided by the voltage divider changes in proportion to a change in thermal voltage.

Abstract: The invention provides a sensor including a first sensor element formed in a first substrate and at least one optical element formed in a second substrate, the first and second substrates being configured relative to one another such that the second substrate forms a cap over the first sensor element. The cap includes a diffractive optical element and an aperture stop which collectively determine the wavelength of incident radiation that is allowed through the cap and onto the at least one optical element.

Abstract: The intercept of a logarithmic amplifier is temperature stabilized by generating a signal having the form H log H where H is a function of temperature such as T/T0. The first H factor is cancelled, thereby generating a correction signal having the form Y log H. The cancellation may be implemented with a transconductance cell having a hyperbolic tangent function. The H log H function may be generated by a pair of junctions biased by one temperature-stable current and one temperature-dependent current. The pair of junctions and the transconductance cell may be coupled together in a translinear loop. A user-accessible terminal may allow adjustment of the correction signal for different operating frequencies.

Abstract: A MEMS device has a mass supported at least in part by a spring. Among other things, the spring has first and second layers, and first and a second electrodes. The first and second layers are between the first and second electrodes, and the first and second layers, which are oppositely polarized, form a bimorph.

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: The invention is directed to a multi-bit digital signal isolation system including a plurality of micro-transformers, each having a primary winding and a secondary winding, a transmitter circuit receiving a multi-bit signal and transmitting an encoded logic signal across the plurality of micro-transformers corresponding to the multi-bit signal, the primary winding of each micro-transformer receiving a signal corresponding to one of at least three possible states, and a receiver circuit receiving the encoded logic signal from the secondary windings of the plurality of transformers, decoding the encoded logic signal and reconstructing the received multi-bit signal based upon the decoded signal.

Abstract: A digital waveform synthesiser (1) is implemented as a single chip integrated circuit on a single chip (2) and comprises a direct digital synthesiser (10) which produces a synthesised output signal waveform on an output terminal (4) which is substantially phase and frequency locked to the phase and frequency of an externally generated input signal applied to an input terminal (5).

Abstract: A radio frequency output power control system is disclosed for use in communication systems that use a modulation scheme having a non-constant amplitude envelope. The system includes a power amplifier having a radio frequency input node for receiving a radio frequency input signal, a power control node for receiving a filtered power control signal, and an output for providing an amplified output signal. The system also includes a variable filter that receives a power control signal at a power control input and a receives a trigger signal at a trigger input, and provides a filtered power control signal to the power control node of the power amplifier responsive to the power control signal and the trigger signal.

Abstract: An input stage receives a differential input signal at first and second input nodes and provides a differential output current at first and second output nodes. The differential output current includes a component taken from the input nodes through first and second impedances, and an additional component generated in response to a sample of the voltage of the differential input signal. A transconductance cell having cross-coupled inputs may generate the additional component of the output current.

Abstract: An amplifier system with digital adaptive power boost includes a charge pump for providing a power supply to an amplifier. The charge pump may switch between a fixed input DC voltage and a boosted value for a certain period of time in response to an increase in an input signal to the amplifier. The charge pump may use a switching transistor which is switched on only when the input signal to the amplifier exceeds a threshold. The amplifier system may be used for envelope tracking, especially for envelope tracking of low duty cycle signals, e.g., xDSL or vDSL.

Abstract: A low-power, low-voltage feedback class AB operational amplifier is disclosed. The minimum supply voltage is one gate-source voltage and two saturation voltages. Currents on the output p-type and n-type transistors are monitored as part of the feedback loop control. Accurate monitoring is achieved by connecting current monitors directly to the corresponding voltage rail. Additional output stages may be selectively connected to the primary output stage to dynamically adjust to changes source conditions. Thus by connecting the appropriate number and type of additional output stages, continuous time adaptive power supply compensation is achieved. Both single ended and differential topologies are described.

Abstract: A transconductance cell includes a positive rail for providing a positive power supply voltage and a negative rail for providing a negative power supply voltage. A pair of voltage inputs, one inverting and one non-inverting, develop a differential voltage input signal having a common mode voltage range from one of the rail voltages to within a volt or less of the other rail voltage. And a pair of cross-coupled transconductor circuits each have: (i.) a source voltage follower responsive to one of the voltage inputs for sourcing relatively unbounded output current at unity voltage gain, (ii.) a sink voltage follower responsive to the other voltage input for sinking unbounded output current to a current output terminal, and (iii) a transconductance resistor connected between the source voltage follower and the sink voltage follower for developing a differential output current proportional to the differential voltage input signal.

Abstract: A signal conditioning circuit dynamically adjusts a compression ratio, so as to compress a signal and avoid limiting to the extent possible, thereby avoiding distorting the signal by clipping. An input signal is applied to the input of a programmed gain amplifier (PGA) or other amplifier whose gain can be controlled by a gain control signal. The input or the output of the PGA is sampled by a level detector to produce a level signal that represents the level of the signal. A variable source produces a variable threshold signal. A comparator compares the level signal to the variable threshold signal to produce a difference signal. Control logic generates the gain control signal from the difference signal. When the level signal exceeds the threshold signal, the control logic alters the gain control signal to reduce the gain of the PGA, and when the level signal is less than the threshold signal, the control logic alters the gain control signal to increase the gain of the PGA.

Abstract: Methods and devices for a remote control device for a display device are disclosed. In one embodiment, the remote control device may comprise a plurality of light sources that each has a light profile angled in a predetermined degree different from other light sources. In another embodiment, the remote control device may comprise a controller; and a plurality of optical detectors coupled to the controller. Each optical detector may generate a pair of electrical signals in response to incident light from a plurality of light sources located on a display device and the controller may calculate the position of the remote control device based on the electrical signals.

Abstract: To compensate for changes in temperature, a pair of bipolar transistors is connected to a voltage divider and receives a differential voltage that varies with temperature. The voltage divider includes a set of resistors placed in parallel. The set of resistors has a resistance that changes with temperature. As the resistance changes with temperature, the differential voltage provided by the voltage divider changes in proportion to a change in thermal voltage.

Abstract: A method of forming a microphone having a variable capacitance first deposits high temperature deposition material on a die. The high temperature material ultimately forms structure that contributes to the variable capacitance. The method then forms circuitry on the die after depositing the deposition material. The circuitry is configured to detect the variable capacitance.

Abstract: A switched-capacitor circuit includes a plurality of cascaded differential-input, single-ended-output amplifiers. A negative feedback path, from an output terminal of a last of the cascaded amplifiers to an input terminal of a first of the cascaded amplifiers, is configured to exclude, and not be shorted out by, any switches.

Abstract: A circuit includes a multi-tanh cell having a common-emitter node to receive a bias current, and an extra transistor coupled to the common-emitter node to dynamically divert a portion of the bias current from the multi-tanh cell. The circuit may be arranged as a multiplier with an input network arranged to apply two or more input signals to the multi-tanh cell. A second multi-tanh cell with an extra transistor may be arranged in a feedback loop where the outputs of the first and second multi-tanh cells are coupled together at an integrating node. A buffer drives the final output and feedback cell to cancel nonlinearities in the multiplier cells.