Abstract: A direct current offset correction system is disclosed for use in an analog signal processing system. The offset correction system includes a comparator unit for comparing the polarity of signals from an analog signal channel and producing a binary output signal. The system also includes a digital accumulator unit that is coupled to the comparator output signal for providing an accumulated average signal over a predetermined period of time. The system also includes a threshold corrective signal unit for determining whether the accumulated signal is within a defined threshold window of acceptable values. The system further includes a correction unit for applying a corrective signal to the analog signal channel.

Abstract: Electronic circuits utilize dynamic bus partitioning to reduce power consumption. An electronic circuit includes several functional electronic blocks, a bus interconnecting the functional blocks, one or more electronically controllable switches partitioning the bus into bus segments and a switch controller. Each of the electronically controllable switches has an on state wherein two of the bus segments are interconnected and an off state wherein the two bus segments are isolated. The switch controller controls the states of the switches in response to control information representative of the source and the destination of each bus transaction. The switch controller may dynamically change the states of the switches between transactions of a sequence of bus transactions. In another embodiment, the switch controller may control the states of the switches to permit two or more bus transactions to be performed simultaneously.

Abstract: A poly fuse trim cell includes a poly fuse and a transistor connected together at a first node; the transistor conducts a current necessary to blow the fuse in response to a control signal. The cell also includes a switching transistor, connected between the first node and a current source circuit. A logic gate is connected to the first node at one input, and to a reset signal at a second input. The output of the logic gate provides the trim cell's output, and controls the switching transistor. When the fuse is intact, the logic gate output is “low” such that the switching transistor is off and the cell's quiescent current is zero. When the fuse is blown, the logic gate output goes “high” upon the occurrence of a reset signal, which turns on the switching transistor and allows the current source circuit to pull down the first node.

Abstract: Space vector modulation methods and structures are provided that reduce feedback errors which degrade motor control performance. In particular, the rotation of a reference voltage vector Vref is modified as it rotates with respect to voltage vectors that each represent a respective one of converter switch states in an electric-motor control system. One embodiment modifies the reference voltage vector Vref as it approaches various voltage vectors and another modifies the reference voltage vector Vref when its magnitude is less than a predetermined magnitude.

Abstract: Mulitplying digital-to-analog converters (MDACs) are provided that reduce signal distortion without significantly raising current demand. These goals are achieved with input structures that lower input impedances and enhance the driving of nonlinear capacitances that are generally presented by the DAC portion of these devices.

Abstract: A magnetic snapback sensor circuit for sensing current transients imposed on the snapback circuit including a current conductor loop; a conductor carrying current from a snapback circuit subject to current transients and intersecting with the conductor loop for magnetically generating a current in the loop; and a current detector circuit for generating an output responsive to the current flowing in the loop induced by a current transient.

Abstract: Differential sampler structures are provided that reduce signal distortion and current demand. The structures include first and second buffers that drive first and second capacitors and first and second switches. First and second current pumps are capacitively coupled and also cross coupled to the first and second capacitors relative to the coupling of the first and second buffers to these capacitors. As a result, signal distortion and current demand are both reduced.

Abstract: A sample rate conversion system developed to implement a rate change of M/N using a very efficient design implementation. The sample rate conversion system of the present invention is implemented as a CIC-based interpolating sample rate converter with noise-shaped control of the N value. For a decimator, noise-shaped control of the M value is utilized. In the interpolator, the N value is the correct value on average, but demonstrates instantaneous errors (“non-uniform” resampling) that are corrected through noise-shaping. The CIC SRC implementation capitalizes on the fact that the outputs of the CIC that are discarded during downsampling need not be calculated by the CIC in the first instance. The combination of the computational simplicity of CIC SRC with noise-shaped, non-uniform resampling performs the sample rate conversion very economically and facilitates conversion between a plethora of sample rates at the input and output without requiring the various filters to be explicitly formulated.

Abstract: This invention discloses a process for forming durable anti-stiction surfaces on micromachined structures while they are still in wafer form (i.e., before they are separated into discrete devices for assembly into packages). This process involves the vapor deposition of a material to create a low stiction surface. It also discloses chemicals which are effective in imparting an anti-stiction property to the chip. These include polyphenylsiloxanes, silanol terminated phenylsiloxanes and similar materials.

Abstract: Drive systems and methods for energizing electronically commutated motors are provided. A drive system includes an inverter for providing pulse width modulated drive signals for energizing an electronically commutated motor in response to control signals and a controller for generating the control signals and for applying the control signals to the inverter such that winding pairs of the electronically commutated motor are energized in a selected sequence. The pulse width modulated drive signals include first and second pulses having first and second pulse widths, respectively, that are unequal. The average voltage applied to the energized winding pair is a function of the time difference between the first and second pulse widths.

Abstract: A bipolar transistor breakdown voltage enhancement circuit extends the voltage swing which can be tolerated at an output terminal driven by an emitter follower-connected bipolar output transistor operating in a high impedance state. The enhancement circuit connects the base of the output transistor to a voltage which extends the allowable high impedance output voltage swing: an NPN output transistor's base is tied to a voltage that is the lower of the output voltage or ground, and a PNP output transistor's base is tied to a voltage which is the higher of the output voltage or VDD.

Abstract: An automatic integrated mechanical and electrical angular motion detector test system includes a test fixture for holding an angular motion detector to be mechanically and electrically tested; a handler subsystem for feeding an angular motion detector to the test fixture; a motor having a rotatable shaft attached to the test fixture for rotating it and the angular motion detector it holds; and an electrical tester for testing the angular motion detector while it is rotating.

Abstract: A power amplifier module includes an input for receiving a signal having an input power level, at least one power amplifier coupled to the input to increase the input power level of the signal to an output power level and a power calibration and control module coupled to the power amplifier for measuring the output power level and correcting the output power level measurement based on a set of factors. The power calibration and control module further controls the at least one power amplifier to produce an output power level equivalent to a target power level. The power calibration and control module may include a power detector, a power calibrator and a power controller. The power amplifier module may further include a power set interface coupled to the power calibration and control module for providing the target power level.

Abstract: A micromachined device has a body suspended over a substrate and movable in a plane relative to the substrate. The body has a perimeter portion, a first cross-piece portion extending from one part of the perimeter portion to another part of the perimeter portion to define at least first and second apertures, a first plurality of fingers extending along parallel axes from the perimeter portion into the first aperture, and a second plurality of fingers extending along parallel axes from the perimeter portion into the second aperture.

Abstract: A MEMS product, particularly an optical MEMS product, and seal therefor. A housing member forms a cavity; a MEMS device is disposed in the cavity; a cap member (which may be an optical window) is dimensioned and configured to substantially cover the cavity; and a sealing member is sealingly attached to and between the housing member and the cap member. The sealing member may have a first attachment portion operatively attached by a first hermetic seal to the housing member and a second attachment portion operatively attached to the cap member by a second hermetic seal and the sealing member is impermeable to gas flow, whereby the cavity is hermetically sealed from ambient atmosphere external to the product.

Abstract: An amplifier system with on-demand power supply boost includes an amplifier circuit for receiving an input signal and a charge pump connected to positive and negative power supplies and having predetermined supply voltages and being responsive to the input signal for increasing beyond the predetermined supply voltages the supply voltage applied to the amplifier in response to an increase in the input signal and a tracking charge pump usable in the amplifier system which includes a charge storage device; a unidirectional isolation device interconnecting the charge storage device and one pole of a power supply; a driver circuit responsive to an input signal and interconnected between both poles of the power supply; the power supply having predetermined power supply voltages; and a bias circuit for biasing the driver circuit to charge the charge storage device in the charge mode and in the boost mode, for increasing beyond the predetermined power supply voltages, the supply voltage supplied by the storage device

Abstract: A circuit includes a current source providing an input current; first and second transistors having common control terminals and forming a current mirror generating a mirror current at the output of the second transistor. A control element having a first and second input and a first and second output is also provided; the first input being connected to the current source, the second input being connected to the output of the second transistor, the first output being connected to the common control terminals, and the second output being connected to the input of the first transistor of the current mirror. The control element is adapted to control the input to the first device and the voltage applied to the common control terminals in response to the inputs to the control device thereby maintaining the defined relationship between the input and output currents of the mirror. A method for implementing a current mirror in low headroom environments is also described.

Abstract: A novel optical-electrical MEMS device overlaid or covered with an optically transmissive substrate held spaced in inverted preferably flip-chip bonded fashion to the device, with transparent electrodes provided in the substrate for generating an upper mirror-actuating field to supplemental the customary lower mirror-well field, enabling complementary operation.

Abstract: An electronic meter, such as an electronic energy meter, includes a sensing circuit for sensing one or more values of a waveform, a memory having a memory bus, a digital signal processor coupled to the memory for calculating at least one parameter value of the waveform in response to the sensed values, and a microcontroller coupled to the memory for performing control functions of the electronic meter. The digital signal processor generates a bus request when access to the memory is required. The microcontroller grants access to the memory in response to the bus request. The sensing circuit may sense and digitize current and voltage values of a polyphase power line.

Abstract: Unwanted voltage drops associated with the bit switches of a DAC are compensated with an output amplifier circuit for the DAC that includes a feedback circuit with a switch compensation resistance element that is connected in a combined series/parallel circuit with a feedback resistance circuit, so as to reduce both the size and associated capacitance of the resistance element.