Abstract: An IC current reference includes a reference voltage Vref, a current mirror, and a transistor connected between the mirror input and a first I/O pin and which is driven by Vref. A resistor external to the IC and having a resistance R1 is coupled to the first I/O pin such that it conducts a current Iref which is proportional to Vref/R1; use of a low TC/VC resistor enables Iref to be an accurate and stable reference current. The current mirror provides currents which are proportional to Iref, at least one of which is provided at a second I/O pin for use external to the IC. One primary application of the reference current is as part of a regulation circuit for a negative supply voltage channel, which can be implemented with the same number of external components and I/O pins as previous designs, while providing superior performance.

Abstract: A power converter system including an LC oscillator circuit, an oscillator drive circuit for driving the LC oscillator circuit, a rectifier circuit coupled to the LC oscillator circuit for providing a DC output, and a switching circuit for controlling the duty cycle of the oscillator drive circuit to modulate the power in the LC oscillator circuit and the rectifier circuit.

Abstract: An amplifier topology includes an input stage comprising a differential pair which conducts respective output currents in response to a differential input signal. Bias current sources provide the pair's tail current and respective bias currents for the input stage in response to a drive voltage. After flowing through the input stage, most or all of the input stage bias currents are summed at a summing node, the summed currents being a current Isum. The input stage also has a feedback loop which includes a bias generator circuit arranged to receive Isum, and to provide the drive voltage to the bias current sources such that Isum is maintained approximately constant. By so doing, the output impedance of the bias current sources is effectively increased, which serves to improve the amplifier's CMR and PSR characteristics.

Abstract: A single chip integrated circuit measuring circuit (1) for determining a characteristic of the impedance of an external complex impedance circuit (2) for facilitating characterization of the impedance of the complex impedance circuit (2) comprises a signal generating circuit (7) for generating a variable frequency stimulus signal for applying to the complex impedance circuit (2). A first receiving circuit (10) receives a response signal from the complex impedance circuit (2) in response to the stimulus signal and conditions the response signal. A first analog-to-digital converter (68) converts the conditioned response signal to a first digital output signal, which is read from the first analog-to-digital converter (68) through a first digital output port (14). The response signal from the complex impedance circuit (2) is a current signal, and a current to voltage converter circuit (64) converts the response signal to a voltage signal.

Abstract: A bandgap voltage reference circuit with an inherent curvature correction which comprises an amplifier having an inverting terminal, a non-inverting terminal and an output terminal is described. A first and second bipolar transistor operable at different current densities are provided each of the transistors being coupled to a corresponding one of the inverting and non-inverting terminals of the amplifier such that a ?Vbe is reflected across a first load element. A current biasing circuit is provided which includes a semiconductor device coupled to each of the first and second bipolar transistors and is configured for applying a non-linear bias current to the first and second bipolar transistors for biasing thereof.

Abstract: A bandgap reference circuit which is operable in low supply conditions is described. Such a circuit includes a second amplifier and a resistor at the output of a bandgap reference cell to create a constant current summing node at which PTAT and CTAT currents are summed. In modifications to the circuit it is possible to also provide a voltage reference node corresponding to the signal provided at the summing node. A further modification enables generation of a second voltage reference whose value is related to the base emitter voltage Vbe of a bipolar transistor. Further modifications provided for the generation of curvature correction within the circuit by biasing each of the first and second bipolar transistors Q1 and Q2 with currents of different forms.

Abstract: A method and system for determining camera positioning information from an accelerometer mounted on a camera. The accelerometer measures the orientation of the camera with respect to gravity. Orientation measurement allows user interface information to be displayed in a “right side up” orientation on a viewfinder for any camera orientation. Alternatively, an artificial horizon indicator may be displayed in the viewfinder. The accelerometer may also measure camera movement. Camera movement information together with camera orientation can be used to determine camera usage. Additionally, camera movement information can be used to determine a minimum shutter speed for a sharp picture.

Abstract: A digital filter uses memory to emulate a variable shift register. Data samples are stored in a memory. The data samples are read from the memory, multiplied with corresponding coefficients stored in the same or a different memory, logically shifted, and written back into the memory so as to emulate a variable shift register. The data samples can be logically shifted by one or more bits at a time.

Abstract: A power converter provides power across an isolation barrier, such as through the use of coils. A coil driver has transistors connected in a positive feedback configuration and is coupled to a supply voltage in a controlled manner by measuring the output power and opening or closing a switch as needed between the power supply and the coil driver. An output circuit, such as a FET driver, can be used with or without isolation to provide power and a logic signal.

Abstract: A semiconductor device comprising a leadframe (4) with a carrier pad (3) bonded thereto, and a die (2) bonded to the carrier pad (3) to form a bonded assembly (5) which is encapsulated in a housing (7) with leads (8) of the leadframe (4) extending therefrom is formed by initially bonding the carrier pad (3) which is pre-coated with a thermosetting first adhesive (20) to the leadframe (4). The first adhesive (20) is raised to its thermosetting cure temperature for bonding the carrier pad (3) to the leadframe (4) by heating the leadframe (4) to a temperature just above the thermosetting cure temperature of the first adhesive (20). A thermosetting second adhesive (22) which is liquid at room temperature is applied to a second major surface (19) of the carrier pad (3), and the die (2) is placed on the second adhesive (22) and aligned with the leadframe (4). The second adhesive (22) is raised to its thermosetting cure temperature to bond the die (2) to the carrier pad (3), and in turn form a bonded assembly (5).

Abstract: A DC to DC converter comprising an inductor, first and second electrically controllable switches and a controller, wherein the first electrically controllable switch is interposed between an input node and a first terminal of the inductor and the second electrically controllable switch extends between a second terminal of the inductor and a common node or a ground, and where a first rectifier extends between the common node or ground and the terminal of the inductor and a second rectifier connects the second terminal of the inductor to an output node, wherein the controller controls the operation of the first and second switches to perform voltage step down or step up, as appropriate, to achieve a desired output voltage and wherein a decision about when to switch the first electrically controlled switch is made as a first function of a voltage error between the output voltage and a target output voltage, and an estimate of the current flowing in the inductor.

Abstract: A control system may be selectively operated in open loop mode, for example, during data bursts. In a power control system, the transmitted power may be selectively held at a constant level, for example, at the end of a ramp period. The forward path gain of a control system may be varied in an inverse-function manner ahead of an integrator. The slope of a measurement signal from a detector may be made to have a complementary polarity.

Abstract: A circuit for removing non-linearity produced when an amplifier includes a load that results in non-linear current levels is provided. The circuit includes a first transistor element being coupled to one of the differential inputs associated with the amplifier. A second transistor element is coupled to another of the differential inputs associated with the amplifier. The second transistor element is coupled to the current associated with the load. Current passing the collectors of the first and second transistors elements are arranged to be always equal so as to eliminate in the circuit the changes between the base currents of the second transistor element and first transistor element caused by the current associated with the load.

Abstract: Coil structures and isolators using them. A coil(s) is (are) used as a magnetic field-generating element(s) paired with another coil(s) or other magnetic field-receiving element(s). The coil(s) is(are) formed in or on a substrate which does not include some or all of the driver (i.e., input) or receiver (i.e., output) circuits. The coil(s) and magnetic field-receiving element(s) thus can be manufactured separately from the driver and/or receiver circuitry, using different processes, instead of subjecting the chip areas containing both input and output circuits to post processing to form the coil(s). Isolators can be assembled using such coils with a resultant lower cost. Isolators also can be assembled using transformers made from such coils wherein the transformers can be driven on either of their windings in order to provide bi-directional isolation with a single transformer.

Abstract: A system, computer program product and method of obtaining a performance parameter associated with a sensor, such as an accelerometer, is provided. The method includes applying an acceleration to the accelerometer and a first frequency to obtain a sensitivity of the accelerometer at the first frequency. A first self-test is performed on the accelerometer. The first self-test includes stimulating the accelerometer with a first self-test stimulation signal encoded with the first frequency, such that the accelerometer outputs a first signal. A self-test equivalent acceleration is then determined based, at least in part, on the first signal and the accelerometer sensitivity at the first frequency. A second self-test is performed on the accelerometer. The second self-test includes stimulating the accelerometer with a second self-test stimulation signal encoded with the second frequency, such that the accelerometer outputs a second signal.

Abstract: The present invention provides a method and apparatus for compensating for temperature effects in the operation of semiconductor processes circuitry, such as reference circuits. The method operates on the realization that the second order effects such as “curvature” in the reference voltage variation over a temperature range is removed. The reference voltage variation over a temperature range can be represented as a straight line. This method provides for the trimming of the absolute voltage by scaling the reference voltage at a first temperature to the desired value by a temperature independent voltage. Then, at a second temperature, the output voltage slope is corrected by adding or subtracting a voltage which is always zero at the first temperature.

Abstract: Transmitter signals are modulated with one or more codes which may represent a pulse even though the code(s) are not shaped as pulses. The code(s) may be generated by defining a pulse by its Fourier components, and then adding random phases to the Fourier components. A time-domain signal may then be created, which may serve as the code to be modulated on a carrier wave. Upon reflection of the transmitter signal, the received signal may be processed by a receiver to recover the pulse. The time-of-flight of the transmitter signal can then be determined, enabling distance measurements to be made.

Abstract: A method of forming a molded sensor includes providing a sensor assembly having a sensor, and a cap coupled to a portion of the sensor, the cap having an opening and forming an interior area. The method also includes blocking the opening in the cap, and molding a moldable material around a portion of the sensor assembly and a portion of a base such that the moldable material is coupled to the sensor assembly and the base, the interior area being substantially free of the moldable material.

Abstract: One or more micromachined (MEMS) switches switch attenuators, such as resistors, into or out of a signal path, such as of a test instrument. The MEMS switches can be fabricated on the same substrate as the attenuators, or the switches or attenuators can be mounted on the same substrate as the others are fabricated. An instrument probe includes attenuators and MEMS switches that are controlled by the instrument and/or by a control circuit in the probe. Optionally, the probe includes reactive elements, such as capacitors, and MEMS switches to compensate for electrical characteristics of the probe and/or probe lead, and the probe or a test instrument automatically sets the MEMS switches to connect appropriate ones of the reactive elements to a signal path within the probe.

Abstract: An integrated circuit includes a substrate, a storage device formed in the substrate to hold bias settings, and operational blocks formed in the substrate, each operational block including an operational circuit and a charge pump to provide well bias voltages to the operational circuit in response to one or more of the bias settings. A method for testing an integrated circuit having two or more operational blocks includes: (a) determining a maximum operating speed of each of the blocks at a minimum supply voltage; (b) selecting a block that has a slow operating speed; (c) selecting a well bias to speed up the selected block; (d) selecting a supply voltage to meet a target operating frequency at the selected well bias and measuring power; (e) repeating acts (b)-(d) while the measured power is less than a baseline power; and (f) saving the selected well bias and supply voltage settings for operation of the integrated circuit.