Abstract: A circuit for measuring a gain of an amplifier includes a first node coupled to an output of the amplifier, a second node, a first circuit coupled to an input and the output of the amplifier, and a second circuit coupled between the first circuit and the second node. The first circuit is configured to cause a first gain drop in a gain to be measured between the first node and the second node. The second circuit configured to cause a second gain drop in the gain to be measured between the first node and the second node.

Abstract: A system to regulate an output voltage based on a reference voltage is described. The system has an error amplifier to determine an error voltage by cumulating a deviation of a feedback voltage from the reference voltage, wherein the feedback voltage is indicative of the output voltage. The system has a PWM unit to generate a PWM control signal based on the error voltage. In addition, the system has a voltage setting unit to set the output voltage based on the PWM control signal. The system has a saturation detection unit to detect a saturation situation of the system. In addition, the system has a clamping means to interrupt a further build-up of the error voltage in the saturated direction while allowing a modification of the error voltage in an opposite direction, opposite to the saturated direction, if a saturation situation is detected.

Abstract: Various embodiments relate to a method and circuit for maintaining zero voltage switching while having a fixed switching frequency, the method including switching on a first switch, on a primary side, at a beginning of a primary stroke of a time period at zero voltage and switching off the first switch at an end of the primary stroke, switching on a second switch, on a secondary side, at a beginning of a secondary stroke of a time period and switching off the second switch at an end of the secondary stoke of a time period and switching on a second switch at a beginning of a ringing period of the time period and switching off the second switch at an end of a bi-directional flyback action.

Abstract: A system that includes a regulator circuit is disclosed. The regulator circuit includes first and second phase units whose outputs are coupled to a power supply node of a circuit block, via respective coupled inductors. The first phase unit may initiate a charge cycle of the power supply node in response to assertion of a clock signal and generate a compensated current using currents measure through both inductors and the clock signal. In response to a determination that the compensated current is greater than a demand current generated using a voltage level of the power supply node and a reference voltage, the first phase unit may halt the charge cycle.

Abstract: In one embodiment a power conversion arrangement comprises a switching converter (DC) with an input which is supplied with an input voltage (Vin) and a first output (Out1) to provide a first output voltage (Vout1) as a function of the input voltage (Vin), a linear regulator (LDO1) with an input coupled to the first output (Out1) of the switching converter (DC), the linear regulator (LDO1) having a second output (Out2) to provide a second output voltage (Vout2) as a function of the first output voltage (Vout1) to a connectable electrical load (CS), a component for sensing (MSI) a load current (Iload) at the second output (Out2) of the linear regulator (LDO1), the component being connected to the second output (Out2) of the linear regulator (LDO1), and a unit for influencing (MVA) the first output voltage (Vout1) as a function of the load current (Iload), the unit (MVA) being connected to the first output (Out1) of the switching converter (DC) and to the component for sensing (MSI) the load current (Iload).

Abstract: To provide a current detection circuit capable of detecting with low current consumption that a prescribed current flows into a current measuring resistor. A current detection circuit is equipped with a reference voltage circuit which has two NMOS transistors having different threshold voltages and a resistor, and generates a reference voltage at the resistor, and a comparison output circuit which is comprised of a PMOS transistor, an NMOS transistor, and a measuring resistor connected in series in a manner similar to a PMOS transistor, an NMOS transistor, and a resistor and outputs a comparison result.

Abstract: A multi-mode envelope tracking (ET) amplifier circuit is provided. The multi-mode ET amplifier circuit can operate in low-resource block (RB) mode and high-RB mode. The multi-mode ET amplifier circuit includes an ET amplifier(s) to amplify a radio frequency (RF) signal(s) to an amplified voltage, low-RB switcher circuitry to generate a direct current (DC) current, and high-RB switcher circuitry to generate an alternating current (AC) current. The amplified voltage, the DC current, and the AC current collectively cause the RF signal to be transmitted at a determined power. A control circuit(s) activates the high-RB switcher circuitry in the high-RB mode to provide the AC current, thus minimizing AC current sourced from the ET amplifier(s). As a result, it is possible to improve efficiency of the ET amplifier(s) and the multi-mode ET amplifier circuit in the high-RB mode and the low-RB mode.

Abstract: A battery backup unit (BBU) for supplying backup power to a load includes at least one battery, an output terminal for coupling to a load, a power converter having an input coupled to the at least one battery and an output coupled to the output terminal, and a bypass circuit having an input coupled to the at least one battery and an output coupled to the output terminal. The power converter is configured to regulate a voltage at the output terminal after startup of the power converter. The bypass circuit is configured to regulate the voltage at the output terminal during startup of the power converter. Other example systems including one or more BBUs are also disclosed.

Abstract: Methods and apparatus for determining a value of a pulse-width modulation (PWM) signal with which to drive a power stage of a DC-to-DC voltage converter having an output inductor coupled between the power stage and an output node that is couplable to a load. A plurality of control schemes for determining a value of a PWM signal with which to drive the power stage are maintained. A value of the PWM signal currently driving the power stage is monitored. A value of an inductor current flowing through the output inductor is monitored. A value of a load current being provided to the load is monitored. One of the plurality of control schemes is selected based on the value of the PWM signal currently driving the power stage, the value of the inductor current, and the value of the load current. The selected control scheme is used to determine a value of a PWM signal with which to drive the power stage.

Abstract: A power supply apparatus of the present invention has an input terminal and an output terminal, and converts an input voltage at the input terminal into a predetermined output voltage at the output terminal. The power supply apparatus includes first and second power supply circuits and a smoothing capacitor. The first power supply circuit is coupled between the input terminal and the output terminal, and converts the input voltage into a predetermined voltage to output the predetermined voltage. The smoothing capacitor is coupled to the output terminal. The second power supply circuit outputs a predetermined voltage or current to the output terminal via the smoothing capacitor, based on a feedback signal corresponding to the predetermined output voltage.

Abstract: A DC-DC converter device and a sub DC-DC converter unit with parallel structure included in the same are disclosed. The DC-DC converter device includes a main DC-DC converter unit configured to receive a (1-1)th reference voltage, a (1-2)th reference voltage and a (n?1)th output voltage, and output an nth first output current corresponding to an nth output voltage; and a sub DC-DC converter unit configured to receive a second reference voltage and the (n?1)th output voltage, and output an nth second output current corresponding to the nth output voltage. Here, an output current in accordance with the nth output voltage corresponds to sum of the nth first output current and the nth second output current.

Abstract: An AC LED driver for providing operating power to an LED load. The AC LED driver includes a first input terminal and a second input terminal, each of the first and second input terminals connectable to an AC input voltage source. The AC LED driver further includes a current limiting capacitor coupled to the first input terminal and a bridge rectifier coupled to the current limiting capacitor, the bridge rectifier having a plurality of rectifying diodes. The AC LED driver also includes a phase angle shift unit coupled to the first input terminal and the bridge rectifier, the phase angle shift unit configured to minimize a phase angle between input line current and input voltage received via at least one of the first input terminal and the second input terminal.

Abstract: A multi-output control system includes a power conversion module, a first active linear module, a second active linear module, a control module and a feedback control module. The control module controls the feedback control module to adjust an output power based on current signals. The first active linear module and the second active linear module determine whether a difference value between a current value of a first output power and a current value of a second output power is greater than a current difference predetermined value based on the current signals, and the control module adjusts a voltage value of the first output power and a voltage value of the second output power to respectively be within a predetermined voltage range based on the current signals.

Abstract: A voltage converter includes a power stage, a passive circuit, a synchronous rectification (SR) switch component, and a control circuit. The passive circuit couples the power stage to an output node of the voltage converter, and is switchably coupled to ground by the SR switch component. The SR switch component includes a plurality of SR switches, which are independently controllable. The control circuit determines which of the SR switches are to be activated/enabled, and only uses those SR switches in its variable switching of the voltage converter. The determination of which SR switches are to be activated/enabled is based upon an estimate of the output current for the voltage converter. By using more SR switches when the voltage converter is fully loaded, and fewer SR switches when it is lightly loaded, the power loss of the SR switch component is minimized and the voltage converter is more power efficient.

Abstract: A voltage system includes a switch device configured to regulate an output voltage at an output port of the voltage system; a pull-up device configured to pull up the output voltage of the voltage system while the pull-up device is activated; and a control device configured to activate the pull-up device when the output voltage is lower than a reference voltage.

Abstract: An overvoltage protection circuit is disclosed. The overvoltage protection circuit includes an input voltage port, an output voltage port, a low pass filter coupled to the input voltage port and a voltage regulator coupled to the low pass filter. The overvoltage protection circuit also includes a transistor having a gate, a drain and a source. The transistor is coupled to the input voltage port and the output voltage port and the gate is coupled to the voltage regulator.

Abstract: A DC-DC converting apparatus for obtaining a constant output voltage includes a DC voltage source that outputs a DC power voltage, a main circuit that converts an input voltage into an output voltage having a set value, an auxiliary circuit, coupled to the DC voltage source, that couples to the main circuit when the input voltage has a fluctuation exceeding a predetermined range so that an output voltage is maintained at the output voltage having the set value.

Abstract: The present disclosure includes circuits and methods for controlling the operation of a switching regulator. Closing and opening high side and low side switches may be controlled so that an inductor current may be used to charge and/or discharge an intermediate switching node when both switches are open. In one embodiment, delays between a low-to-high transition and a high-to-low transition of an AC stage may be cycled over multiple periods of a DC stage.

Abstract: Provided is a voltage regulator configured to suppress a variation of an output voltage so as to stably operate even when a power supply voltage varies. The voltage regulator includes a control circuit having an input terminal connected to a drain of an output transistor, and an output terminal connected to an error amplifier circuit. The control circuit is configured to cause a boost current to flow through an error amplifier circuit when the output voltage varies beyond a predetermined value.

Abstract: Methods and apparatus to reduce localized transistor operating temperature increases in fully integrated voltage regulator circuits are provided. Transistor self-heating effects are reduced by dispersing heat more evenly over the integrated circuit die, via use of nested voltage regulator circuits and/or use of more than one transistor in a voltage regulator circuit pass device. An electrically parallel-connected group of multiple individual integrated transistors may be laid out across cooler areas of the integrated circuit die, such as in substantially linear sets or rings of devices near the outer die perimeter. Each transistor in the group may better disperse its own heat if it is thermally segregated from other self-heating devices, as through a minimum physical layout spacing. Transistor bias voltage mismatch tolerances, load currents, and routing resistances may interrelatedly determine the number of individual transistors needed in a group.

Abstract: A controller for use with a power converter including a switch configured to conduct to provide a regulated output characteristic at an output of the power converter, and method of operating the same. In one embodiment, the controller includes a linear control circuit, coupled to the output, configured to provide a first control signal for the switch as a function of the output characteristic. The controller also includes a nonlinear control circuit, coupled to the output, configured to provide a second control signal for the switch as a function of the output characteristic. The controller is configured to select one of the first and second control signals for the switch in response to a change in an operating condition of the power converter.

Abstract: A low dropout regulator is provided. The low dropout regulator includes an output-stage circuit, a reference-voltage generation circuit, a timing controller, and an active low dropout circuit. When the low dropout regulator is at an operation mode, the output-stage circuit is controlled by a first enable signal to generate first output voltage to an output node of the low dropout regulator. The reference-voltage generation circuit is controlled by a bias voltage to generate a first reference voltage. The timing controller is coupled to the output node and receives the first reference voltage. When the low dropout regulator is in the operation mode, the timing controller programs the first enable signal according to the reference voltage and the voltage at the output node. When the low dropout regulator is in a standby mode, the active low dropout circuit generates a second output voltage to the output node.

Abstract: A power supply system includes a plurality of power supply circuits connected to a common output node and a control unit that controls outputs of the plurality of power supply circuits such that an output value at the output node follows an output target value at the output node. The control unit is configured to change the output of part of the plurality of power supply circuits when there is a deviation smaller than or equal to a predetermined value between the output value and the output target value.

Abstract: A low voltage AC power controller uses a line coupled capacitor AC to DC converter circuit to obtain energy from AC line power supplied to an AC load and may be used with an external high voltage AC switching device to control power supplied to the AC load. The line coupled capacitor AC to DC converter circuit provides a low power device that senses characteristics of the power supplied to the load and can communicate sensed information and/or receive control information related to the power supplied to the load.

Abstract: The present invention provides an apparatus and method for an envelope amplifier using adjustment of a switch current, in order to maximize the efficiency of the envelope amplifier at the entire sections of envelope output power. The apparatus and method can extend the battery lifetime of portable wireless devices such as smart phones or mobile phones or application devices such as notebook computers, which use a battery as a power supply.

Abstract: A thermostat for use in a climate control system has a power stealing circuit that provides power from a voltage supply through a load of the climate control system when the load is in an “off” mode. The power stealing circuit has a current limiting circuit that provides a maximum level of instantaneous current predetermined to be a threshold beyond which the load is switched to an “on” mode.

Abstract: The present invention provides a parallel current-sharing device and control method without a current-sharing bus, for implementing parallel current sharing of direct-current outputs of a plurality of power conversion submodules. The parallel current-sharing device comprises a voltage control module and a plurality of power conversion submodules. The voltage control module and the plurality of power conversion submodules having parallel outputs form an outer voltage loop. The power conversion submodules comprise respective inner current loops and sample respective current feedback signals to generate inner current loop control signals, and the inner current loop control signals are superposed with an outer voltage loop control signal to control output of the power conversion submodules. An independent current bus is not required, and only one unidirectional outer control voltage loop is required.

Abstract: A power management apparatus cooperates with a controlled apparatus and is electrically connected to a power system. The power management apparatus includes an energy storing module, a switching module and a comparing module. The energy storing module is electrically connected to the controlled apparatus, and the switching module is electrically connected to the energy storing module. The comparing module is electrically connected to the switching module and receives a detection signal. The comparing module generates a periodic signal to control the switching module according to the detection signal. The energy storing module stores an electric energy during a cycle of the periodic signal and releases the electric energy during other cycle after the said cycle. Thereby, the power management apparatus is capable of effectively protecting the controlled apparatus, avoiding the waste of the power, and storing and using extra power.

Abstract: The present invention relates to a power supply and measuring device for an electronic device (e.g. an IED), which is configured to provide supervision, control, protection, communication and/or monitoring functionalities for LV or MV circuits or apparatuses. The power supply device comprises a current transformer, which is operatively associated to a main power line. An input section of the power supply device comprises a burden regulating stage that is configured to regulate the equivalent electric load at the secondary winding of said current transformer. An output section of the power supply device provides a supply voltage suitable to feed said electronic device.

Abstract: A low-dropout regulator includes an error amplifier to provide a control signal, a first transistor, and a second transistor. The first transistor receives the control signal and has a source-drain path electrically coupled between a supply voltage node and a load, the first transistor to power the load in response to a voltage on the supply voltage node rising above an absolute value of a threshold voltage of the first transistor. The second transistor has a source-drain path electrically coupled between the supply voltage node and the load, the second transistor to receive the control signal in response to the voltage on the supply voltage node rising above a particular voltage.

Abstract: A voltage regulator for outputting a voltage having a predetermined relationship with a reference voltage, the voltage regulator includes a driver circuit configured to generate the output voltage, a feedback loop configured to feed back a sensed voltage that is representative of the output voltage to a control unit and the control unit, configured to compare the sensed voltage with the reference voltage and, only if the difference between them exceeds a predetermined threshold, control the driver circuit to adjust the output voltage.

Abstract: Various embodiments may provide a circuit arrangement. The circuit arrangement may include a carrier having at least one electrically conductive line; a plurality of discrete encapsulated integrated circuits arranged on the carrier; wherein a first integrated circuit of the plurality of integrated circuits is in electrical contact with a second integrated circuit of the plurality of integrated circuits to form a first current path bypassing the carrier; and wherein the first integrated circuit of the plurality of integrated circuits is in electrical contact with the second integrated circuit of the plurality of integrated circuits to form a second current path via the at least one electrically conductive line.

Abstract: A dual mode voltage regulator according to one embodiment includes a passive regulator circuit, a switching regulator circuit, and a controller circuit configured to determine parameters of an external select input. The controller is configured to selectively couple, on a cold boot up, either the passive regulator circuit or the switching regulator circuit between an input voltage port and an output load based on the determination of parameters.

Abstract: Systems and methods for operating a switching converter are disclosed. The switching converter includes a high-side transistor coupled between a voltage input and a switching node and a low-side transistor coupled between the switching node and ground. The switching converter also includes a high-side driver coupled to drive a gate of the high-side transistor, a charge pump coupled to the high-side driver, and a bootstrap circuit, which includes a pass transistor coupled between the charge pump and the switching node, and a pull-down transistor coupled between the charge pump and ground.

Abstract: A system and method reduces power consumption by an electronic power control system when a controller of the electronic power control system reduces sense signal monitoring during a standby mode of the controller. The electronic power control system includes a controller to control a switching power converter. The controller operates in at least two modes, standby and active modes. Energy savings during standby mode can be achieved in a variety of current and/or voltage sensing configurations. During the standby mode, the controller generates a signal to at least intermittently disable sensing of an input voltage to the switching power converter or at least intermittently disabling sensing of an input voltage and an output voltage. Disabling sensing reduces energy losses associated with an input voltage sense signal itself and with circuitry in the controller used to process the input voltage signal.

Abstract: A power converter system includes a converter configured to be coupled to a power generation unit for receiving current from the power generation unit. A bus is coupled to the converter, and energy is stored within the bus when the current is conducted through the power converter system. A damping circuit is configured to be coupled to the bus and to the power generation unit, and a control system is coupled to the converter and to the damping circuit. The control system is configured to selectively discharge at least a portion of the energy stored within the bus through the damping circuit when the control system determines that a predetermined condition is met.

Abstract: A circuit for measuring the gain of an operational amplifier is provided. The circuit comprises a first operational amplifier, a first resistive device and a second resistive device. The first operational amplifier has an original gain and includes a first input terminal and a second input terminal. The first resistive device is coupled between the first input terminal and the second input terminal of the first operational amplifier. The second resistive device is coupled to the second input terminal of the first operational amplifier. The first resistive device and the second resistive device are configured to reduce a predetermined amount of gain from the original gain of the first operational amplifier.

Abstract: A multi-phase boost converter with phase self-detection and a detecting circuit thereof are provided. The multi-phase boost converter comprises M switching circuits, a capacitor, a control circuit and a detecting circuit. Each switching circuit has an input end and an output end. N inductors are coupled in parallel between the input ends and an input voltage. The output ends are coupled to an output voltage. The control circuit controls the conduction status of the switching circuits according to a feedback voltage corresponding to the output voltage. The detecting circuit coupled between the input ends and the control circuit detects the conduction status between the input voltage and each of the input ends, for outputting a first control signal. The control circuit controlled by the first control signal selectively controls at least one of the switching circuits. N is a positive integer less than or equal to M.

Abstract: A Switch Node Assisted Linear architecture, including a linear amplifier in parallel with a switched converter, is configurable in two tracking modes: (a) a SMAL regulator in which the amplifier sets load voltage with an envelope tracking bandwidth, and the switched converter is configured for current assist, and (b) a Switched Mode Power Supply configuration in which the amplifier is switch-decoupled, and the switcher circuit is switched configured with an output capacitor, operable as an SMPS providing load voltage with an adaptive tracking bandwidth that is less than the envelope tracking bandwidth.

Abstract: Circuits and methods for providing short-circuit protection in a voltage regulator are disclosed. A voltage regulator includes a pass switch, a voltage error amplifier, a driver circuit, and a short-circuit protection circuit. The pass element is coupled to a power supply and a load, and generates an output voltage in response to a drive signal. The voltage error amplifier generates an error voltage based on a difference of a reference voltage and the output voltage and the driver circuit generates the drive signal in response to the error voltage. The short-circuit protection circuit senses the drive signal and provides a high-resistance path to the driver circuit in a short-circuit event. In a short-circuit event, the high-resistance path clamps current in the driver circuit thereby clamping a voltage difference between the first and third terminals and thereby limiting a load current in the short-circuit event.

Abstract: A device and method for sensing an inductor current in an inductor is provided that generates a voltage signal proportionate to the inductor current if the inductor is connected to a positive supply and simulates the inductor current if the inductor is not connected to the positive supply. The voltage signal may be generated by sampling an input voltage from the inductor onto a capacitor if the inductor is connected to the positive supply. The inductor current may be simulated by generating a simulation current and pushing the simulation current onto the capacitor.

Abstract: A bidirectional DC-to-DC converter is configured to convert electrical energy from a first and second DC source. The bidirectional converter includes an output capacitor providing an output voltage and a first and second inductor. The first inductor is arranged between a positive connection of the second DC source and a first contact of a first switch. The second inductor is arranged between a negative connection of the first DC source and a second contact of the first switch. A buffer capacitor is arranged between a negative output of the first DC source and a positive output of the second DC source. A second and third switch are arranged in series with the first switch. The second switch is arranged between the first contact of the first switch and the positive DC output. The third switch is arranged between the second contact of the first switch and the negative DC output.

Abstract: A DC-to-DC voltage converter using switching frequency detection is provided. The DC-to-DC voltage converter includes a voltage conversion block including a power switch configured to be turned on in response to a power driving signal and to provide an input supply voltage to be output as the converted output voltage when the power switch is turned on, wherein the converted output voltage has a level that varies depending on a duty cycle of the power driving signal, and a switching control block that receives the converted output voltage and a feedback signal to control the duty cycle of the power driving signal based on a frequency of a feedback signal, the feedback signal having the same period as the power driving signal. Accordingly, when the level of the input supply voltage is changed, the converted output voltage can be recovered to the target level while the switching frequency of the power driving signal is maintained at the same value as before the change of the level of the input supply voltage.

Abstract: This disclosure relates to radio frequency (RF) power converters and methods of operating the same. In one embodiment, an RF power converter includes an RF switching converter, a low-drop out (LDO) regulation circuit, and an RF filter. The RF filter is coupled to receive a pulsed output voltage from the RF switching converter and a supply voltage from the LDO regulation circuit. The RF filter is operable to alternate between a first RF filter topology and a second RF filter topology. In the first RF filter topology, the RF filter is configured to convert the pulsed output voltage from a switching circuit into the supply voltage. The RF filter in the second RF filter topology is configured to filter the supply voltage from the LDO regulation circuit to reduce a ripple variation in a supply voltage level of the supply voltage. As such, the RF filter provides greater versatility.

Abstract: Described herein is an apparatus for dynamically adjusting a voltage reference level for optimizing an I/O system to achieve a certain performance metric. The apparatus comprises: a voltage reference generator to generate a voltage reference; and a dynamic voltage reference control unit, coupled with the voltage reference generator, to dynamically adjust a level of the voltage reference in response to an event. The apparatus is used to perform the method comprising: generating a voltage reference for an input/output (I/O) system; determining a worst case voltage level of the voltage reference; dynamically adjusting, via a dynamic voltage reference control unit, the voltage reference level based on determining the worst case voltage level; and computing a center of an asymmetrical eye based on the dynamically adjusted voltage reference level.

Abstract: A microcontroller system includes a main voltage regulator and a low power voltage regulator having a static current consumption less than the static current consumption of the main voltage regulator. A power state controller enables the low power voltage regulator during a power saving mode. On exiting the power saving mode, the power state controller enables the main voltage regulator and disables the low power voltage regulator after determining that the main voltage regulator is ready. The switching circuitry can be asynchronous.

Abstract: Described herein is an apparatus for dynamically adjusting a voltage reference level for optimizing an I/O system to achieve a certain performance metric. The apparatus comprises: a voltage reference generator to generate a voltage reference; and a dynamic voltage reference control unit, coupled with the voltage reference generator, to dynamically adjust a level of the voltage reference in response to an event. The apparatus is used to perform the method comprising: generating a voltage reference for an input/output (I/O) system; determining a worst case voltage level of the voltage reference; dynamically adjusting, via a dynamic voltage reference control unit, the voltage reference level based on determining the worst case voltage level; and computing a center of an asymmetrical eye based on the dynamically adjusted voltage reference level.

Abstract: A power saving circuit for an electronic device is disclosed. The power saving circuit includes a direct-current (DC) power supply, a sensing unit, and a control unit. The DC power supply is used for providing a DC current. The sensing unit, coupled to the DC power supply, is used for detecting the DC current and operating to generate a voltage signal according to the DC current. The control unit, coupled to the sensing unit, is used for determining whether a system circuit of the electronic device has a light load or a heavy load and generating an enable signal.

Abstract: A method of on/off modulation of a very high frequency switching cell-based power converter includes receiving an input voltage signal to be applied to a plurality of series stacked very high frequency power converter cells for producing an output voltage and/or current, and controlling a portion of the plurality of series stacked high frequency power converter cells through on/off modulation of at least one of the plurality of series stacked high frequency power converter cells to control the output current and/or the output voltage.

Abstract: In a multi-phase power supply voltage regulator functioning at a nominal switching frequency, one or more phases are kept off for optimizing energy efficiency at relatively low load conditions. Reactivation of stand-by phases in response to a load increase transient is made more efficiently by exploiting information already present in the output voltage control loop. The technique comprises a) deriving from the control loop information on the equivalent nominal switching frequency given by the product of the nominal switching frequency by the number of active phases; b) updating at every beat of a clock signal the instantaneous value of the equivalent switching frequency; c) determining the band of equivalent switching frequency values to which the instantaneous value belongs; d) logically combining the equivalent switching frequency information with a determined band of output current level, for switching on one or more stand-by phases in response to a load increase transient.