Abstract:
A method for determining an optimal design for wiring interconnect and driver power for a designed target delay begins at the floor planning stages of the chip design and may be repeated during the design process. The designer initially specifies a maximum width that wires are allowed to use and a target delay value. Then the designer gives values to weights used in the calculation of an optimization function G(d,p,w), where d is the delay, p is the power, and w is wire width. An "ideal" slope ##EQU1## is calculated, assuming zero resistance. The designer chooses a slope decrease value from the "ideal" slope value. For each set wire width, the delay (at the proper slope) belonging to that particular wire width is obtained. With these inputs, an optimization program according to the invention is run. This program then calculates values of the function G(d,p,w) for increasing wire pitches, starting with the minimum allowed by the technology. The process continues until (1) the target delay is set by the designer is met, (2) the largest pitch value allowed by the designer is reached, or (3) further calculation will not yield a smaller value for the optimization function.
Abstract:
An apparatus for misalignment compensation in optical joysticks is described. The optical joystick includes a light source, a plurality of photodetectors, and circuitry for controlling operation of the optical joystick. In some embodiments, each of the photodetectors may partitioned into a plurality of photodetector elements and select photodetector elements are configured to be individually activated in order to cause an electrical shifting of the selected photodetector elements to achieve a different operational alignment position of optical components of the optical joystick. In some embodiments, the light source may be similarly be calibrated by individually activating portions of a light-source array to cause an electrical shift. Various other embodiments and methods of operation are also described.
Abstract:
A MEMS resonator has a resonator mass in the form of a closed ring anchored at points around the ring. A set of ring comb electrode arrangements is fixed to the ring at locations between the anchor points, to couple the input (drive) and output (sense) signals to/from the resonator mass.
Abstract:
A magnetoresistive sensor comprising first and second magnetoresistive elements is disclosed. Each magnetoresistive element is coupled at a respective first end to a common ground terminal and comprises one or more magnetoresistive segments, each overlying a corresponding segment of an excitation coil. The resistance of the magnetoresistive segments in each of the first and second magnetoresistive elements is the same and the resistance of the segments of the excitation coil corresponding to the first magnetoresistive element is the same as the resistance of the segments of the excitation coil corresponding to the second magnetoresistive element.
Abstract:
A pressure/vacuum sensor and method, comprising: driving a MEMS piezoresistive resonator (8) into resonant vibration, applying Joule heating to the resonator (8); and sensing a variable parameter that varies in response to the tendency of the resonant frequency (fo) to depend upon the temperature of the resonator (8), the temperature thereof depending upon the pressure. The variable parameter may be the resonant frequency of the resonator (8), or a change therein, or may be derived from a feedback loop, being for example a time integrated feedback signal (82) or a reading (94) of the sense current (22), the loop keeping the resonant frequency constant in opposition to the above mentioned tendency. A reference MEMS capacitive resonator (62) may be located in the vicinity of the resonator (8) for compensating purposes.
Abstract:
A device has a micro electromechanical structure (10) with a first arm (102), at least one second arm (104a, b) connected to each other via a connection (100). Both arms (102, 104a, b) and the connection (100) are preferably made of a single crystalline body. The first and second arm (102, 104a, b) have end portions attached to a substrate, but otherwise the arms and their connection are free to move relative to the substrate. The first and second arm (102, 104a, b) extending from the end portions to the connection (100) along different directions, preferably perpendicularly to each other. An electrode (12) is provided on the substrate, adjacent to the micro electromechanical structure (10) to excite vibration of the structure. The two arms in different directions make it possible to reduce the nonlinearity of the stiffness during vibrations of the structure.
Abstract:
A MEMS resonator has a resonator mass in the form of a closed ring anchored at points around the ring. A set of ring comb electrode arrangements is fixed to the ring at locations between the anchor points, to couple the input (drive) and output (sense) signals to/from the resonator mass.
Abstract:
A microphone comprises a substrate (20), a microphone membrane (10) defining an acoustic input surface and a backplate (11) supported with respect to the membrane with a fixed spacing between the backplate (11) and the membrane (10). A microphone periphery area comprises parallel corrugations (24) in the membrane (10) and backplate (11). By using the same corrugated suspension for both the membrane and the backplate, the sensitivity to body noise is optimally suppressed.
Abstract:
A MEMS resonator, comprising a planar resonator body formed of two different materials with opposite sign temperature coefficient of Young's modulus. A first portion of one material extends across the full thickness of the resonator body. This provides a design which allows reduced temperature drift.
Abstract:
A piezoresistive MEMS oscillator comprises a resonator body, first and second drive electrodes located adjacent the resonator body for providing an actuation signal; and at least a first sense electrode connected to a respective anchor point. The voltages at the electrodes are controlled and/or processed such that the feedthrough AC current from one drive electrode to the sense electrode is at least partially offset by the feedthrough AC current from the other drive electrode to the sense electrode.