Abstract: Manufacturing a power transistor by forming a gate structure on a first layer, forming a trench in the first layer, self aligned with the gate structure, and forming part of the transistor in the trench. By forming a spacer next to the gate, the spacer and gate can be used as a mask when forming the trench, to allow space for a source region next to the gate. The self-aligning rather than forming the gate after the trench means the alignment is more accurate, allowing size reduction. Another aspect involves forming a trench in a first layer, filling the trench, forming a second layer on either side of the trench with lateral overgrowth over the trench, and forming a source region in the second layer to overlap the trench. This overlap can enable the chip area to be reduced.

Abstract: A circuit for determining a direction of rotation of an electric motor, the motor having asymmetry and/or eccentricity in a profile of back electromotive force as a function of angular position of a rotor with respect to a stator, the circuit receiving a signal representing the BEMF, and use the corresponding asymmetry and/or eccentricity in the signal to derive the direction of rotation. The signal representing the back emf can be generated by a control circuit. The control circuit can have a feedback loop regulator to generate a control signal (TL or TR) to control a current drive circuit (11,12) to control an amplitude of current (iw) in the windings, the feedback loop regulator being arranged to compare the amplitude of the current (iw) in the windings with a reference value (iset), and use the control signal to provide the signal representing the back electromotive force.

Abstract: An echo detection circuit that detects an echo by detecting the magnitude of a digitally mixed representation of the received acoustic signal and reference sine and cosine signals. That magnitude is then compared against an echo threshold to verify the presence or absence of an echo signal. A low pass filter with a configurable cut-off frequency may be used to define the selectivity of the echo detector.

Abstract: A driver circuit suitable for outputting a signal onto an output line affected by conducted EMI, has a slope control circuit and an output circuit, (op-amp, Mo, M13 to M21). It can be used for driving a LIN network. The slope control circuit outputs a slope controlled version of the input signal to the output circuit, which (M6,M7) is arranged to reduce an amount of conducted EMI induced DC shift in the output circuit. This can involve clipping a feedback signal, and regulating an output stage of the op-amp to prevent the DC shift. Having a separate output circuit can help shield the slope control circuit from the EMI on the output line.

Abstract: A differential operation circuit that uses the differential input signals to generate a reference voltage that fluctuates with the common mode voltage of the differential input signals. The reference voltage includes a common mode component that generally follows the common mode voltage of the differential input signals. The common mode component of the reference voltage is used to fully or almost fully offset the common mode voltage of the differential input signals, thereby increasing the differential operation circuit's common mode rejection characteristics.

Abstract: A integrated semiconductor device has a first semiconductor layer of a first conductivity type, a second semiconductor layer of the first conductivity type over the first layer, a third semiconductor layer of a second conductivity type over the second layer, an isolation trench extending through the entire depth of the second and third layers into the first layer, and a first region of the second conductivity type located next to the isolation trench and extending from an interface between the second and third layers, along an interface between the second layer and the isolation trench. This first region can help reduce a concentration of field lines where the isolation trench meets the interface of the second and third layers, and hence provide a better reverse breakdown characteristic.

Abstract: A spin on glass SOG layer 30 is formed, then a PECVD barrier layer 40 over the SOG layer. Holes 50 in the SOG layer for vias are formed with a wine glass profile, so that in a peripheral region around the periphery of the holes, the barrier layer is thinner or absent, and ion implantation is performed substantially perpendicular to the layers, to reach the SOG layer through the barrier layer preferentially in the peripheral region. This enables the implantation to be concentrated on the peripheral region, without the need for implantation at a high angle and wafer rotation. This enables the manufacturing process to be simplified and hence costs reduced. By concentrating the implantation in the peripheral region where it can reduce moisture transfer to material in the holes, there is less risk of deplanarization due to the SOG shrinkage associated with ion implantation.

Abstract: The present invention provides a semiconductor device (20) comprising a trench (5) formed in a semiconductor substrate formed of a stack (4) of layers (1,2,3), a layer (6) of a first, grown dielectric material covering sidewalls and bottom of the trench (5), the layer (6) including one or more notches (13) at the bottom of the trench (5) and one or more spacers (14) formed of a second, deposited dielectric material to fill the one or more notches (13) in the layer (6) formed of the first, grown dielectric material. The semiconductor device (20) according to the present invention shows improved breakdown voltage and on-resistance. The present invention furthermore provides a method for the manufacturing of such semiconductor devices (20).

Abstract: A regulated mirror current source circuit has an output transistor, a regulator for controlling the output circuit, and a current mirror having two or more current paths. The first path of the mirror is coupled in series with a current path of the output circuit, and the second path is coupled to the regulator, to provide feedback. The feedback can provide better precision, or reduced component area. The circuit can include cascode transistors, and the regulator can have integral control. The output transistor gate-source voltage is overdriven to reduce “on” resistance of the output transistor. When the output transistor is a high voltage transistor, its area can be reduced without sacrificing compliance.

Abstract: An integrated power semiconductor device has an isolation structure having two or more isolation trenches, and one or more regions in between the isolation trenches, and a bias arrangement coupled to the regions to divide a voltage across the isolation structure between the isolation trenches. By dividing the voltage, the reverse breakdown voltage characteristics such as voltage level, reliability and stability can be improved for a given area of device, or for a given complexity of device, and avalanche breakdown at weaknesses in isolation structures can be reduced or avoided.

Abstract: A power supply device is described comprising a DC voltage supply, a power section connected to the DC supply for supplying DC power from the DC voltage supply to first and second outlet ports for connection to a remote device via a cable connection, a voltage boosting circuit for generating a voltage above that of the DC supply, an energy absorbing circuit connected between an output of the voltage boosting circuit and a ground potential, and a diode connection means between the first outlet port and the energy absorbing circuit. The major components of the power supply device may be implemented as an integrated circuit.

Abstract: The present invention provides a method to compensate for the sensitivity drift of a magnetic field sensor for sensing a magnetic field. The magnetic field sensor comprises at least four electrodes. The method comprises a first step where a first set of two electrodes is used to bias the sensor and a second set of two electrodes is used to sense an output signal of the magnetic field sensor, and a second step where the second set of two electrodes is used to bias the sensor and the first set of two electrodes is used to sense an output signal of the magnetic field sensor. The method is characterized in that at least one of the first or the second step is subdivided in at least a first sub-step and a second sub-step. A reference magnetic field has first magnetic field parameters, e.g. a first amplitude and/or direction, in the first sub-step and second magnetic field parameters, a second amplitude and/or direction, in the second sub-step.

Abstract: A DC current regulator circuit comprises a first circuit node (32) which is operable to receive an external input voltage. A transistor (M1) has an input, a first leg and a second leg. The first leg of the transistor is isolated from the first circuit node (32). An amplifier (10) has an output connected to the input of the transistor (M1), a first amplifier input for receiving a reference voltage (VREF) and a second amplifier input connected to the first circuit node (32). A low-pass filter (33) connects between the output of the amplifier and the first circuit node (32). A current mirror (36) connects in series with the second leg of the transistor (M1) and has a first branch (38) for providing a regulated output current and a second branch (37) which connects to the first circuit node (32). The current regulator has reduced sensitivity to conducted EMI received at the first circuit node (32).

Abstract: An integrated circuit has drive circuitry to drive the windings of an electrical motor, means to make a measurement from the drive circuitry during rotation of the motor, suitable for use as motor control feedback, and has an output contact through which the motor control feedback measurement is available as an analog output signal. It can be used with an external motor control circuit coupled to receive the analog output signal to generate motor control signals, to control the drive circuitry. The analog feedback output gives more flexibility to the design of a motor control loop in terms of bit resolution, bandwidth and choice of discrete time or continuous time control.

Abstract: A circuit for determining a direction of rotation of an electric motor, the motor having asymmetry and/or eccentricity in a profile of back electromotive force as a function of angular position of a rotor with respect to a stator, the circuit receiving a signal representing the BEMF, and use the corresponding asymmetry and/or eccentricity in the signal to derive the direction of rotation. The signal representing the back emf can be generated by a control circuit. The control circuit can have a feedback loop regulator to generate a control signal (TL or TR) to control a current drive circuit (11,12) to control an amplitude of current (iw) in the windings, the feedback loop regulator being arranged to compare the amplitude of the current (iw) in the windings with a reference value (iset), and use the control signal to provide the signal representing the back electromotive force.

Abstract: A regulator circuit receives a power supply and provides a regulated power supply output suitable for integrated circuitry. It has a controllable current source circuit, a controller and a capacitor, such that an output of the controllable current source circuit can provide a lower frequency current part of the regulated power supply output, and the capacitor can supply a higher frequency current part of the regulated power supply output. The controllable current source circuit is controlled according to feedback from the regulated power supply output, and to restrict a rate of change of the output of the controllable current source circuit. The amount of EMI noise caused by high rate of change of current in power supply lines to the regulator circuit can be reduced. This can be done more efficiently or using a smaller capacitor than known arrangements.

Abstract: The invention relates to a signaling system for use in a system for monitoring and/or controlling a stack of power cells. The stack of power cells is series connected, i.e. the negative terminal of one power cell is connected to the positive electrode of the adjacent power cell. A monitoring device is associated with each power cell to monitor characteristics of the power cell (temperature, voltage). Every monitoring device is powered by the power cell it is associated. The monitoring device monitors the status of the cell (e.g. it measures the difference of potential between the positive terminal and the negative terminal of that cell but it may also measure the temperature of the power cell, the pH of the electrolyte if the power cell Ci is a battery, etc. and communicates information on the status of the cell to other monitoring devices. The monitoring devices are daisy chained.

Abstract: The present invention is related to a transmission system for sending digital data on a digital bus (1), to which are connected a number of master and slave modules. The system is characterized by the fact that a number of modules may comprise two connectors (20, 21) to said bus, and a switch (22) or switches (52, 53), allowing the interruption of said bus. This design allows an address setting procedure to take place, before starting normal operation. During this initialization, the addresses of the modules are set by consecutively closing the switches, and setting the address. Every time a switch is closed in one module, the following module can receive its address. The invention is related to several embodiments of the system allowing this procedure, and to the method of initializing such a system.

Abstract: A driver circuit suitable for outputting a signal onto an output line affected by conducted EMI, has a slope control circuit and an output circuit, (op-amp, Mo, M13 to M21). It can be used for driving a LIN network. The slope control circuit outputs a slope controlled version of the input signal to the output circuit, which (M6,M7) is arranged to reduce an amount of conducted EMI induced DC shift in the output circuit. This can involve clipping a feedback signal, and regulating an output stage of the op-amp to prevent the DC shift. Having a separate output circuit can help shield the slope control circuit from the EMI on the output line.

Abstract: A comparator has first and second current paths, each passing from an input through a transistor, through a current source to ground, the second current path also having a reference voltage drop element coupled in series with the second input. The gates of the transistors are coupled to form a current mirror. The reference voltage drop element enables higher voltages to be input and compared to higher thresholds above an internal supply voltage level without the need for dividing resistors to reduce the input voltage. Avoiding such resistors means the power dissipation and the silicon area used can be kept lower. ESD vulnerability is reduced since the inputs are not coupled to gates of MOS transistors. Overvoltage protection across the source and gate of the second transistor can be added.