Abstract: A circuit for generating an output voltage, and regulating the output voltage to a target voltage, is described. The circuit comprises a pass device coupled between an input voltage level and an output voltage level, an error amplifier stage configured to generate a first control voltage on the basis of a reference voltage and the output voltage, a buffer stage configured to generate a drive signal for the pass device on the basis of the first control voltage, and a tracking circuit configured to track a voltage across the pass device and to generate a second control voltage on the basis of the voltage across the pass device. The buffer stage comprises a variable resistance element, for limiting a current flowing through the buffer stage on the basis of the second control voltage.

Abstract: A regulator configured to provide at an output node a load current at an output voltage is described. The regulator comprises a pass transistor for providing the load current at the output node. Furthermore, the regulator comprises feedback means for deriving a feedback voltage from the output voltage at the output node. In addition, the regulator comprises a differential amplifier configured to control the pass transistor in dependence of the feedback voltage and in dependence of a reference voltage. The regulator further comprises compensation means configured to determine a sensed current which is indicative of the load current at the output node. Furthermore, the compensation means are configured to adjust an operation point of the regulator in dependence of the sensed current and in dependence of a value of a track impedance of a conductive track which links the output node to a load.

Abstract: An low dropout regulator and method that has reduced quiescent current consumption is presented. The voltage regulator circuit comprises an output terminal, a first circuit branch connected between an input voltage level and the output terminal, a second circuit branch connected between the input voltage level and a predetermined voltage level, a first current mirror for mirroring a current flowing in the second circuit branch to the first circuit branch, a first feedback circuit to regulate the output voltage, and a second feedback circuit for controlling the second switching element. The second feedback circuit comprises a current sensing means for sensing a current that depends on a current flowing in the first circuit branch and to control the second switching element such that the current flowing through the second circuit branch is limited to a current that depends on the current sensed by the current sensing means.

Abstract: A power converter comprises an inductor coupled between a switching terminal and an output terminal of the power converter, a high side switching element coupled between an input terminal of the power converter and the switching terminal, a low side switching element coupled between the switching terminal and a reference terminal, and a feedback circuit comprising a continuous comparator unit configured to compare a ramp signal with an error signal using a first enable signal, a latched comparator unit configured to compare the ramp signal with the error signal using a second enable signal, wherein the error signal is based on a difference between a reference voltage and an output voltage at the output terminal of the power converter.

Abstract: A DC-DC switching converter soft start method is provided, using a scaled switch size. An increased switch resistance, higher than the normal operating switch resistance, is achieved during the startup of the switching converter. The on-resistance of the high side switch, together with a minimum duty cycle, reduces the peak inductor current of the switching converter. After a startup period, the switching converter reverts back to a normal switch resistance.

Abstract: A haptic system with a haptic actuator and a voltage sensor coupled to the haptic actuator, to sense a voltage across the haptic actuator. The voltage across the haptic actuator has a back electromotive force component. There is a current regulator coupled to the haptic actuator and to the voltage sensor. The current regulator is adapted to provide a current signal to drive the haptic actuator and to adjust the current signal based on the back electromotive force component. For example, the voltage across the haptic actuator may be a direct voltage or a representation of the voltage such as a filtered value of the voltage.

Abstract: A current regulator for a flash LED driver is presented. An apparatus and method for a current regulator that provides a current and exhibits good noise rejection is presented. A current regulator for regulating a current through a circuit element contains a first node at a first voltage, the current through the circuit element being dependent on the first voltage and a positive feedback loop coupled to the first node, The positive feedback loop is arranged to provide a signal to remove a voltage shift from the first voltage in response to a decrease or increase of the first voltage by the voltage shift.

Abstract: A level shifter does not require any DC (standby) current consumption and has a fast operation with low propagation delay. The level shifting from input to output voltage ranges is performed by a pair of level shifting capacitors. The input-output power voltages domains are unrestricted and flexible. DC isolation is deployed between power domains. Symmetrical rise/fall times are without duty cycle distortion. Over voltage stress is reduced by using metal capacitors. Finally the level shifter does not use high-voltage devices for level shifting purpose. Embodiments of level shifters provide one-way level shifting and bi-directional level shifting.

Abstract: A power converter to convert power between a first converter voltage at a first converter port and a second converter voltage at a second converter port is presented. It contains a first capacitor network, an inductor and a first switching matrix to arrange the first capacitor network and the inductor within different states. One of the states is a bypass state enabling current to flow from the first converter port or from ground through the first capacitor network to the second converter port without going through the inductor. Another state is an inductor state enabling current to flow from the first converter port or from ground through the inductor to the second converter port. The power converter also includes a control unit to control the first switching matrix repeatedly in a recurrent sequence of the different states.

Abstract: An apparatus and method for a temperature and calibration utilizing resonant frequency peaks in an oscillator. A circuit providing resonant peaks for utilization for temperature measurements comprising a resonator device for providing an oscillating source, a variable gain-bandwidth amplifier in parallel with the crystal/resonator for providing modulation of the gain and/or bandwidth driving the crystal/resonator, and control of resonant peaks for selection for oscillation, a first capacitor electrically coupled to the parallel combination of the input of the variable gain-bandwidth amplifier, and the resonator device for providing charge storage for oscillation, and a second capacitor electrically coupled to parallel combination of the output of the variable gain-bandwidth amplifier, and the resonator device for providing charge storage for oscillation.

Abstract: A solid state driver circuit that is compatible with either a low frequency mains or magnetic ballast supply or a high frequency electronic ballast input is presented. An input detection circuit detects the frequency of the supply and selectively adjusts the drive circuit to act as a linear regulator when an electronic ballast is detected, or as a switched mode regulator when mains or a magnetic ballast is detected. There is also provided a method of driving a solid state lamp. The method has a step which receives an input power supply. The method also has an enabling operation of a switching regulator or the shorting of a switching regulator according to the frequency of the input power supply.

Abstract: A circuit for driving a power switch is presented. The circuit includes a first power switch coupled to a second power switch via a switching node and a driver coupled to the first power switch, where the driver contains an energy storing element coupled to the switching node. The circuit also contains a sensor to sense an electrical parameter of the driver and a charger coupled to the sensor. The charger provides a charge current to charge the energy storage element, and to control the charge current based on the electrical parameter. In particular, a circuit for driving a power switch based on a III/V semiconductor is presented. In addition, a method of powering a power switch driver is presented. The method includes sensing an electrical parameter of the driver and adjusting a current to charge the energy storing element based on the electrical parameter.

Abstract: A multi-phase power converter is described, which is configured to convert power between an input port and an output port. The multi-phase power converter comprises a basic switched converter comprising a basic inductor, wherein the basic switched converter is configured to convert power between the input port and the output port. Furthermore, the multi-phase power converter comprises an auxiliary switched converter comprising an auxiliary inductor, wherein the auxiliary switched converter is configured to convert power between the input port and an auxiliary port. In addition, the multi-phase power converter comprises a set of configuration switches configured to couple the auxiliary port to the output port, or to arrange the auxiliary inductor and the basic inductor in series.

Abstract: A direct AC LED lighting device is provided with a low-pass filter for filtering a threshold time in which a post diode bridge voltage exceeds an LED threshold voltage during a current AC half cycle for the post diode bridge voltage.

Abstract: A voltage sensing circuit for a switching power converter includes a comparator having a comparator input stage that processes a voltage from a main DAC and a current from a tracking DAC.

Abstract: A method and apparatus for limiting or preventing electromagnetic interferences in a switching converter are presented. In particular, a power circuit provided with an active electromagnetic interference filter is presented. There is an electromagnetic interference EMI reduction circuit for use with a switching converter. This EMI reduction circuit has a current source and is adapted to regulate a voltage across the current source to provide a current having a constant average value. The switching converter is adapted to provide a converter current, and the current source constant average value may be substantially equal to an average value of the converter current. The circuit has a variable resistance; and an adjuster adapted to adjust the variable resistance based on the converter current. The adjuster may have a comparator, which is adapted to compare a voltage value at a terminal of a transistor switch, and a reference value.

Abstract: Circuits and methods to achieve a hysteretic buck-boost converter system, separating buck and boost pulses based on monitoring a difference between the output voltage of the buck-boost converter and a reference voltage (error voltage) or alternatively based on monitoring additionally coil current or load current or both currents have been disclosed. The performance of the buck-boost converter can be further improved by using an optional output voltage change block monitoring if the output voltage rises or falls. The buck-boost converter disclosed has a very simple topology without a modulator block, which is regulating the duty cycle and without frequency compensation.

Abstract: An integrated circuit coupled to an external serial bus is presented. A method for prefetching data from an external serial bus is presented. The integrated circuit comprises a serial interface, a data cache, and a prefetch control unit. The serial interface detects a data address on the serial bus and reads data elements from data storage units. The data storage units may be internal or external to the integrated circuit. The data cache is coupled to the serial interface via an internal bus. The prefetch control unit instructs the serial interface to prefetch a data element associated with the data address by reading the data element from a target data storage unit associated with the data address. The data element and the data address are written to the data cache. When a read request is detected, the data element can be quickly accessed from the data cache.

Abstract: A transient response circuit provides faster transient response time of an electronic device so that less overshoot or undershoot of an output signal of the electronic device occurs when a large load and/or line transient signal is present at an input and/or output terminal of the electronic device. The transient response circuit has a transient detection circuit and an assist circuit. The transient detection circuit monitors a feedback signal applied to an input terminal of the control stage, and generates transient detection signals indicating that detection of a large load and/or line transient signal has occurred. The assist circuit communicates receives the transient detection signal and charges or discharges a loop filter capacitor of the control stage for causing the control stage to regulate the output signal to decrease overshoot or undershoot upon receipt of the transient detection signal.

Abstract: An amplifier comprising a differential amplifier configured to be provide a comparator function, and a gain trimming circuit is electrically configured to provide gain trimming using a T-network comprising a varistor element. In addition, a method of trimming the gain of a differential amplifier, comprising the steps of a first step, (a) providing the differential amplifier comprising resistors in both of its paths, a second step, (b) providing a varistor in a T-network between both said paths; and lastly, a third step, (c) trimming the gain of the differential amplifier by adjusting the varistor's resistance.