Abstract: Circuits and methods to control current through a device biasing an output device in case the supply voltage is not higher than the output voltage are disclosed. The circuits and methods are applicable to e.g. LDOs, amplifiers, or buffers. A control loop detects if the supply voltage is not higher than the output voltage and regulates the drain-source voltage of the biasing device. The disclosure reduces power consumption in a driver stage in case the supply voltage is not higher than the output voltage.

Abstract: Circuits and methods to reduce the size of output capacitors of LDOs or amplifiers are disclosed. Nonlinear mirroring of the load current allows scaling of gain or adapting small signal impedance of a pass transistor depending on other inputs, in case of a preferred embodiment, allows to reduce small signal impedance at the gate of the pass transistor as the load current increases, hence allowing to reduce the size of an output capacitor without compromising stability of the system.

Abstract: The present document relates to multiphase DC-DC power converters. In particular, the present document relates to the compensation of the phase offset incurred in multiphase DC-DC power converters which are controlled based on coil current zero crossing. A control circuit for a multiphase power converter is described. The multiphase power converter comprises a first and a second constituent switched-mode power converter, wherein the first and second constituent power converters provide first and second phase currents, respectively. The first and second phase currents contribute to a joint load current of the multiphase power converter. The first and second constituent power converters comprise first and second half bridges with first and second high side switches and first and second low side switches, respectively.

Abstract: A driver circuit using a power converter allows free-wheeling detection and/or provision of supply voltage. A circuit controls a switching state of a power switch. A first port of the switch is coupled to an inductor. The circuit is coupled to a control port of the switch wherein the control port of the switch is different from the first port of the switch. The circuit comprises a unit generating a signal for controlling the switching state of the switch wherein the signal is provided to the control port of the switch. Furthermore, the circuit comprises free-wheeling sensing means to detect an oscillation of a voltage at a measurement port of the switch wherein the measurement port of the switch is different from the first port of the switch and wherein the oscillation of the voltage at the measurement port indicates free-wheeling of the inductor.

Abstract: An apparatus and method for a linear voltage regulator with improved voltage regulation is disclosed. A linear voltage regulator device with improved voltage regulation that combines good resiliency to noisy ground reference, high Power Supply Rejection Ratio (PSRR), good current load regulation with changes in the current load and good feedback loop stability. The linear voltage regulator comprises of an amplifier, a current source, a pass gate, a current load, a first feedback loop, a second feedback loop, a second amplifier and second pass gate. A second feedback loop is formed to control the bias of the first feedback loop.

Abstract: A dual mode low dropout voltage regulator has a low dropout regulation mode and a bypass mode and provides a smooth transition between mode transitions taking place under load. When an accessory requires a larger voltage level, a bypass signal commands the dual mode low dropout voltage regulator to go into bypass mode and transfer voltage level of the unregulated input voltage source to the output of the dual mode low dropout voltage regulator. The dual mode low dropout voltage regulator provides a smooth transition to the bypass to prevent the output of the dual mode low dropout voltage regulator from decreasing or having a “brown out” until a pass transistor is forced to turn on fully to provide the voltage level of the unregulated input voltage source to fully bypass the low dropout regulating mode of operation.

Abstract: Circuits and methods to maintain a resistive voltage divider ratio during start-up of an electronic circuit comprising a feed-forward capacitor across a feedback resistor using a dynamic start-up circuit are disclosed as e.g. a LDO or an amplifier. In a preferred embodiment of the disclosure is applied to an LDO. Modification of the resistive voltage divider ratio caused by the feed-forward capacitor during start-up is prevented while the voltage level of a voltage access point of the voltage divider on the feed-forward capacitor is maintained. A start-up circuit comprises a start-up capacitor and a start-up comparator.

Abstract: Multi-stage amplifiers, such as linear regulators or linear voltage regulators (e.g. low-dropout regulators) configured to provide a constant output voltage subject to load transients are presented. A multi-stage amplifier, having a differential amplification stage configured to provide a stage output voltage at an output node, based on a first input voltage and a second input voltage is presented. Furthermore, the multi-stage amplifier comprises a second amplification stage comprising an amplifier current source configured to provide an amplifier current; and an amplifier transistor arranged in series with the amplifier current source; wherein a gate of the amplifier transistor is coupled to the output node of the differential amplification stage. In addition, the multi-stage amplifier comprises a detection circuit.

Abstract: A time off estimator and an adaptive controller implemented on an integrated circuit to emulate current dependent zero crossing circuitry to permit improved performance of a buck type switching mode power supply. The time off estimator circuit is enhanced by an automatic correction circuit for the timing of a zero crossing where energy to a reference capacitor returns to zero and is turned off awaiting the next cycle where the capacitor is again charged and discharged.

Abstract: A controller for controlling the illumination state of a light source of solid state lighting devices such as LED or OLED assemblies, is presented. The controller controls the light source according to a plurality of illumination states subject to determine an event of a plurality of events. The controller controls a power converter that converts power derived from an input voltage waveform of line voltage power supply into a drive signal for the light source. The controller determines an event of a plurality of events encoded within the input voltage waveform of the line voltage power supply. A first state processor determines a next illumination state of the plurality of illumination states, based on the determined event and based on the current illumination state. Line voltage Switch event detection is performed while no power is available at the line voltage terminals.

Abstract: Driver circuits comprise power converters detecting automatically a topology used by the driver circuits. A controller controls a plurality of different types of power converters in accordance to a corresponding plurality of different operation modes. The controller comprises a measurement pin coupled to a first topology resistor of a first power converter of a type from the plurality of different types. The different types of power converters comprise topology resistors of corresponding different resistor values. The controller senses a voltage at the measurement pin wherein the voltage at the measurement pin is indicative of a voltage drop at the first topology resistor. Furthermore, the controller determines a type of the first power converter based on the sensed voltage, and selects an operation mode for controlling the first power converter.

Abstract: A method and a system for increasing the open loop gain of linear regulators are presented. A linear regulator to derive an output voltage from an input voltage is described. The linear regulator contains an amplifier to derive an amplifier output signal from an amplifier input signal, and a pass device to convert the amplifier output signal into the output voltage. The linear regulator has a positive feedback loop using a positive feedback gain ?, and a negative feedback loop using a negative feedback gain ?. In addition, the linear regulator has a combining unit to determine the amplifier input signal from the input voltage, from the positive feedback signal and from the negative feedback voltage. A transfer function of the linear regulator exhibits a first and a second pole at a first frequency wp1 and at a second frequency wp2, respectively.

Abstract: A light bulb assembly comprises an electrical connection module, a driver circuit configured to provide electrical energy at a drive voltage, and a light source. The driver circuit converts electrical energy at an input voltage to the electrical energy at the drive voltage. A controller is configured to control the power converter to provide electrical energy at the drive voltage. The controller stops operation at an interruption of electrical energy to the driver circuit. The controller is configured to resume operation subsequent restoration of electrical energy to the driver circuit. The controller is configured to maintain the timing voltage above a first voltage level when the controller is in operation and to determine the duration of an interruption of electrical energy to the driver circuit.

Abstract: The present document relates to voltage mirror circuits. A voltage mirror circuit, having an input node and an output node is configured to provide substantially equal voltage levels at the input node and the output node. The voltage mirror circuit comprises an input current source transistor, an input gain transistor arranged in series with the input current source transistor such that the input gain transistor is traversed by the bias current, wherein the voltage level at the input node corresponds to the voltage drop across the input current source transistor and the input gain transistor. An intermediate gain transistor forms a first current mirror with the input gain transistor. An output current source transistor forms a second current mirror with the intermediate current source transistor. An output gain transistor is wherein the voltage level at the output node corresponds to the voltage drop across the output current source transistor and the output gain transistor.

Abstract: A control logic of a switched DC-to-DC converter allows continuous switching to bring the DC-to-DC converter to a final output value during a startup phase, it allows skipping of clock switching pulses if they are not needed and allows burst mode of switching pulses dependent on a load applied to the output voltage of the DC-to-DC converter. No digital or analog regulator is required for the control logic.

Abstract: The present document relates to multi-stage amplifiers, such as linear regulators or linear voltage regulators (e.g. low-dropout regulators) configured to provide a constant output voltage subject to load transients. A multi-stage amplifier is described, having a differential amplification stage which comprises a differential transistor pair. The differential amplification stage is configured to provide a stage output voltage at a stage output node of the differential transistor pair, based on a first input voltage at a first stage input node and a second input voltage at a second stage input node. The differential transistor pair also comprises a reference node. The differential amplification stage further comprises an active load comprising a first diode transistor coupled to the reference node and a first mirror transistor coupled to the stage output node.

Abstract: The present document relates to solid state lighting (SSL) devices. A driver circuit for phase-cut dimmable SSL based lighting assemblies is described. A control circuit for a power converter is provided. The power converter is configured to convert an input power derived from a mains power supply into a drive power for a light source. The control circuit comprises a dimmer mode detection unit to determine a first dimmer mode. The first dimmer mode indicates if the input power has been derived from the mains power supply using a dimmer. The control circuit comprises a state processor configured to determine a first operation mode of the power converter. The pre-determined first state information is dependent on the first dimmer mode. The control circuit comprises a first control unit configured to generate a first control signal for operating the power converter in accordance to the first operation mode.

Abstract: A driver circuit for a switched-mode power converter is configured to perform hysteretic control of a switched-mode power converter. The switched-mode power converter comprises an inductor configured to store energy during a first state of the switch and to release energy towards a load of the switched-mode power converter during a second state of the switch. The driver circuit comprises a filter unit which is configured to determine a command signal based on a gate control signal applied to a gate of the switch. The command signal is indicative of a current through the inductor. The driver circuit comprises hysteretic control circuitry configured to generate the gate control signal based on the command signal; wherein the switch alternates between the first and second state when being subjected to the gate control signal.

Abstract: The present document relates to multi-stage amplifiers, such as linear regulators or linear voltage regulators (e.g. low-dropout regulators) configured to provide a constant output voltage subject to load transients. A multi-stage amplifier is described. The multi-stage amplifier comprises a first amplification stage configured to provide a stage output voltage at a stage output node. Furthermore, the amplifier comprises an intermediate amplification stage comprising an amplifier current source configured to provide an amplifier current and an amplifier transistor arranged in series with the amplifier current source. A gate of the amplifier transistor is coupled to the stage output node of the first amplification stage. The intermediate amplification stage is configured to provide an amplified or attenuated stage output voltage at a midpoint between the amplifier current source and the amplifier transistor.

Abstract: An overshoot reduction circuit within a low dropout voltage regulator eliminates an overshoot at an output terminal resulting from a transient fault condition occurring at an input or output terminal. The overshoot reduction circuit monitors to sense if there is a transient fault condition occurring at the input or output terminal and provides a Miller capacitance at the output terminal of a differential amplifier of the low dropout voltage regulator to prevent the output of the differential amplifier from being discharged to ground during the transient. A control loop circuit balances current within an active load of the differential amplifier to clamp the output of the differential amplifier to its normal operating point. When the transient fault condition ends, the output voltage of the differential amplifier is set such that a pass transistor of the low dropout regulator responds quickly to resume the regulation to reduce or eliminate the overshoot.