Abstract: During its first and second residence times, corresponding first and second currents flow between a charge pump and a circuit that connects to one of the charge pump's terminals. Based on a feedback measurement from the charge pump, a controller adjusts these first and second currents.

Abstract: A voltage divider circuit arrangement includes a resistive divider circuit portion constructed from first and second resistors (R1, R2) The first and second resistors are connected in series and are arranged to provide a refresh voltage (Vrefresh) at a refresh node between them. A capacitive divider circuit portion is constructed from first and second capacitors (C1, C2). The first and second capacitors are connected in series and are arranged to provide an output voltage (Vout) at an output node. A switching circuit portion is arranged intermittently to switch the voltage divider circuit arrangement between a first mode wherein the resistive divider is enabled and the output node is connected to the refresh node, and a second mode wherein the resistive divider is disabled and the output node is not connected to the refresh node.

Abstract: A current control circuit can include: a current detection circuit configured to obtain a current detection signal for characterizing an output current of a switched capacitor converter, where the switched capacitor converter includes a plurality of first switch groups coupled between an input terminal and a ground, and where each first switch group comprises two switches coupled in series; and a voltage regulation circuit configured to regulate the output current by adjusting an equivalent impedance of the switched capacitor converter in accordance with the current detection signal.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed. An example apparatus includes a gate controller coupled between an input terminal and an intermediate node, the gate controller including a first transistor coupled between the input terminal and a first node; a second transistor coupled between the first node and the intermediate node; a third transistor coupled between the input terminal and the intermediate node; and a charge pump coupled to the intermediate node; a switching network coupled between the intermediate node and an output terminal, the switching network including a high-side drive (HSD) transistor having a HSD gate terminal coupled to the intermediate node, the HSD transistor coupled between an input voltage and a switch node.

Abstract: What is provided is a voltage-generating circuit that uses dynamic reference voltage to accurately control the step-up of a generated voltage. A voltage-generating circuit 100 of the invention includes a charge pump 110 outputting voltage Vpump, a regulator 120, and a controlling circuit 140. The regulator 120 includes a comparator 122 and a comparator 132. The comparator 122 compares voltage Vdivide generated by the charge pump 110 with a reference voltage Vref, and outputs a comparison result CMP_OUT. The comparator 132 compares voltage Vdivide2 generated by the charge pump 110 with a reference voltage VrefRRC with a controlled rising speed, and outputs a comparison result CMP2_OUT. The controlling circuit 140 controls the charge pump 110 based on CMP_OUT and CMP2_OUT.

Abstract: A light-emitting diode driving system including a load, a power supply circuit and a light-emitting diode driving device is provided. The load includes one or more light-emitting diode strings. The power supply circuit outputs an output voltage to drive the load according to a feedback signal. The light-emitting diode driving device includes at least one current source, at least one comparator and a control logic circuit. The current source outputs a current to drive the load. The comparator compares a first voltage from the current source to a reference voltage and outputs a second voltage according to a comparison result. The control logic circuit includes a control node. The control logic circuit receives the second voltage through the control node and converts the second voltage to a control signal to adjust a resistance value of a variable resistor circuit. A light-emitting diode driving device is also provided.

Abstract: A power converter includes a switched-capacitor conversion circuit and an inductor buck circuit. The switched-capacitor conversion circuit receives an input voltage, and is operated, according to the first switching frequency, to convert the input voltage into an intermediate voltage. The inductor buck circuit and the switched-capacitor conversion circuit are connected in series. The inductor buck circuit receives the intermediate voltage, and generates an output voltage on a conversion output terminal thereof according to the intermediate voltage. The minimum value of the first switching frequency is determined by the intermediate voltage.

Abstract: A control method used in a switched tank converter with a first conversion unit, a second conversion unit and a rectification unit, includes: based on current flowing through the resonant tanks in the first and second conversion units, determining when to turn on the high side switches of the first and second conversion units, and when to turn on the low side switches of the first and second conversion units; detecting whether current flowing through the first, second, third and fourth rectification switches crosses zero; and based on the detection result, respectively determining when to turn off the high side switch of the first conversion unit, when to turn off the high side switch of the second conversion unit, when to turn off the low side switch of the second conversion unit, and when to turn off the low side switch of the first conversion unit.

Abstract: A method comprises during a first half cycle, configuring a first switch to operate as an always-on switch, turning on a second switch prior to turning on a third switch and turning off the third switch prior to turning off the second switch, wherein the first switch and the second switch are connected in series and further in parallel with the third switch between a first terminal of a power source and a filter and during a second half cycle, configuring a fourth switch to operate as an always-on switch, turning on a fifth switch prior to turning on a sixth switch and turning off the sixth switch prior to turning off the fifth switch, wherein the fourth switch and the fifth switch are connected in series and further in parallel with the sixth switch between a second terminal of the power source and the filter.

Abstract: A system, supplied by a power supply, is switched into standby mode by an electronic device that includes a charging input coupled to a charge voltage obtained from the voltage delivered by the power supply. A first input is coupled to the power supply and a power supply output is coupled to the system. A storage capacitive element is coupled to the charging input and configured to be charged by the charge voltage. A switching circuit, coupled between the first input and the power supply output, disconnects the power supply output from the first input when the voltage across the terminals of the storage capacitive element is higher than a threshold. A discharge circuit discharges the storage capacitive element so that the capacitor voltage becomes lower than the threshold. The switching circuit further re-connects the first input to the power supply output at the end of the discharge period.

Abstract: A charge pump circuit has a plurality of charge pump stages cascaded to one another between an input terminal and an output terminal to provide an output voltage having a boosted value with respect to the input voltage. A clock generator is configured to generate a clock signal provided to the charge pump stages to perform the boosting of the input voltage. An output-voltage regulation feedback closed-loop is coupled to the clock generator to perform a regulation of the output voltage based on a feedback voltage. A discharge control stage is configured to control a discharge of the charge pump circuit by generating a first discharge control signal configured to disable the output-voltage regulation feedback closed-loop or a second discharge control signal configured to reduce the frequency of the clock signal.

Abstract: A voltage regulator device and a control method thereof are provided. The voltage regulator device includes a voltage regulator and a path switch. The voltage regulator includes an output node and a voltage divider circuit. The output node is used to generate a control voltage. The voltage divider circuit generates an overshoot reference voltage according to an input voltage. A first node of the path switch is coupled to the output node, a second node of the path switch is coupled to a reference voltage node, and a control node of the path switch receives the overshoot reference voltage. When the control voltage is greater than the sum of the overshoot reference voltage and a threshold voltage of the path switch, the path switch is turned on to direct a charge at the output node to the reference voltage node.

Abstract: An integrated power supply and modulator system includes integrated power supply and modulator system includes three subsystems: a switched-capacitor voltage balancer stage; a magnetic regulation stage; and at least one output switching stage. In one embodiment, the integrated power supply and modulator system further includes startup circuitry, feedback/feedforward circuitry and control circuitry.

Abstract: Described herein is a technology for implementing a scalable SCIB regulator for high conversion step down application. Particularly, the SCIB is configured to include stacked input switch circuits with parallel-connected output switch circuits. The input switch circuits are stacked with or without DC shift switch circuits in between. Furthermore, the input voltage is stepped down to a biasing voltage by input switch circuits and then is regulated to one or more output voltages having one or more independent and predetermined values by output switch circuits. The input switch circuits, output switch circuits and DC shift switch circuits can be modified for scalable power capability and ease of control and manufacturing.

Abstract: A gate driving circuit for providing a high driving voltage includes a first N-type high-voltage transistor and a second N-type high-voltage transistor connected in series between a driving voltage output node and a system low-voltage source. A voltage difference between a system high-voltage source and the system low-voltage source is greater than a withstand voltage of the first or second N-type high-voltage transistor. When the driving voltage output node is to output a system high voltage, the first N-type high-voltage transistor and the second N-type high-voltage transistor are turned off. Deep N-type well regions of the first N-type high-voltage transistor and the second N-type high-voltage transistor are applied with a first bias voltage. A voltage difference between the first bias voltage and the system low-voltage source is smaller than an interface breakdown voltage between the deep N-type well region and a P-type well region of the second N-type high-voltage transistor.

Abstract: Disclosed are a DC voltage conversion circuit, a DC voltage conversion method and a liquid crystal display device.

Abstract: This disclosure describes techniques for controlling a power supply voltage for a high-side gate driver that is used in a power converter. In some examples, in response to an overvoltage condition that occurs on an input voltage lead of a power converter, a power converter may decouple a terminal of a charge pump capacitor from the input voltage lead, and couple the terminal of the capacitor to a reference voltage lead. In further examples, in response to an overvoltage condition that occurs on an input voltage lead of a power converter, a power converter may turn off both switching transistors.

Abstract: Various buck-boost amplifier architectures are disclosed. In some architectures, a plurality of amplifiers use one or more inductors from a shared bank of inductors as needed to deliver variable amounts of power to respective loads. In some architectures, each amplifier includes multiple inductors and switches that are controlled to vary the number of inductors used in an amplifier based on a power requirement of the amplifier to drive its load. In some architectures, the switches include well switching devices. In some architectures, each amplifier drives multiple loads and is operated in a single inductor multiple output (SIMO) mode. In all architectures, the loads include speakers, piezo elements, and motors.

Abstract: A gate driver for a high-side NMOS power transistor in a DC/DC boost converter includes first and second switches coupled in series between an output pin and the gate of the high-side transistor. A third switch is coupled between the gate and a switch-node between the high-side and low-side transistors, the switch node also being coupled to an input pin. Fourth and fifth switches are coupled in series between the output pin and a clamp pin. Sixth and seventh switch are coupled in series between the output pin and a ground pin. First and second bootstrap capacitors have respective first terminals coupled to a first node between the first and second switches. The first capacitor has a second terminal coupled to a node between the fourth and fifth switches; the second capacitor has a second terminal coupled to a node between the sixth and seventh switches.

Abstract: An electronic device includes: a clock booster configured to generate a boosted intermediate voltage greater than a source voltage, wherein the clock booster includes: a controller capacitor configured to store energy for providing a gate signal, wherein the gate signal is for controlling charging operations to generate the boosted intermediate voltage based on the source voltage, and a booster capacitor configured to store energy according to the gate signal for providing the boosted intermediate voltage, wherein the booster capacitor has greater capacitance level than the controller capacitor; and a secondary booster operatively coupled to the clock booster, the secondary booster configured to generate an output voltage based on the boosted intermediate voltage, wherein the output voltage is greater than both the source voltage and the boosted intermediate voltage.

Abstract: A reverse bias voltage adjuster is provided. The reverse bias voltage adjuster includes an operating voltage generating circuit and a voltage adjusting circuit. The operating voltage generating circuit generates an operating voltage according to a burnin-test signal, a power start signal, and a reverse bias enable signal. In a normal operation mode, the operating voltage is a first voltage value, and in a burnin-test mode, the operating voltage is a second voltage value, wherein the second voltage value is less than the first voltage value. The voltage adjusting circuit is provided with a switch, and in an initial time interval in the burnin-test mode, the voltage adjusting circuit adjusts voltage value of the reverse bias by turning on the switch.

Abstract: A charge pump having only NMOS devices charges a plurality of capacitors to a parallel charged voltage level by electrically connecting the capacitors in parallel between an input voltage node and a ground by activating a plurality of first NMOS transistor switches and a plurality of second NMOS transistor switches and deactivating a plurality of third NMOS transistor switches. The charge pump then generates a series capacitor output voltage level at a capacitor series output node by electrically connecting and discharging the capacitors in series between the input voltage node and the capacitor series output node by activating the third NMOS transistor switches and deactivating the first NMOS transistor switches and the second NMOS transistor switches.

Abstract: A flipping-capacitor rectifier circuit that enhances an output power of a piezoelectric energy harvester (PEH). The flipping-capacitor rectifier circuit includes a flipping capacitor, a plurality of switches, and an active rectifier. The flipping capacitor is connected in parallel with the PEH and forms at least three reconfiguration phases by turning on one or more of the switches. The active rectifier connects with the flipping capacitor in parallel and rectifies an AC voltage of the PEH. The flipping capacitor flips a voltage across a capacitor of the PEH to enhance the output power of the PEH by extracting power from the capacitor of the PEH.

Abstract: Certain aspects of the present disclosure provide apparatus and techniques for charging a multi-stack battery pack. For example, certain aspects provide a circuit for charging a battery pack having multiple battery cells. The circuit generally includes a voltage regulator circuit and charge pump circuitry having an input coupled to an output of the voltage regulator circuit, and an output coupled to a first battery charging terminal. In certain aspects, the first battery charging terminal may be configured to be coupled to a terminal of a first battery cell of the multiple battery of the battery pack.

Abstract: A charge pump system including charge pump circuitry, a charge pump controller, and current limit circuitry. The charge pump circuitry has an input coupled to a supply input node and has an output for developing a drive voltage. The charge pump controller controls the charge pump circuitry to increase the drive voltage above a supply voltage provided to the supply input node. The current limit circuitry limits current through the charge pump circuitry to a limited current level that is less than a maximum current level during a current limit mode to reduce current spikes at the nodes of the charge pump system that may generate EMI. A current mirror may be used as the current limit circuitry to directly limit current through switches of the charge pump circuitry. The timing of the charge pump switches may also be modified such as inserting strategic delays to reduce the current spikes.

Abstract: A downhole tool may include a voltage multiplier within a housing. The voltage multiplier may transform input power to the downhole tool from a first voltage to a second voltage higher than the first. The downhole tool may also include multiple shielding rings surrounding at least the voltage multiplier to reduce electric field stresses within the downhole tool. Additionally, the downhole tool may include an insulator located between the shielding rings and the housing.

Abstract: During its first and second residence times, corresponding first and second currents flow between a charge pump and a circuit that connects to one of the charge pump's terminals. Based on a feedback measurement from the charge pump, a controller adjusts these first and second currents.

Abstract: A thyristor or triac control circuit includes a first capacitive element that is series-connected with a first diode between a first terminal and a second terminal intended to be coupled to a gate of the thyristor or triac. A second capacitive element is coupled between the second terminal and a third terminal intended to be connected to a conduction terminal of the thyristor or triac on the gate side of the thyristor or triac. A second diode is coupled between the third terminal and a node of connection of the first capacitive element and first diode.

Abstract: In some examples, an electrical power system includes a differential bus including a high-side rail and a low-side rail, a power source configured to generate power, and a bulk capacitor coupled between the high-side rail and the low-side rail, the bulk capacitor configured to filter the power generated by the power source. The electrical power system also includes a converter configured to convert the power filtered by the bulk capacitor and a pre-charging circuit comprising one or more switches and a middle capacitor, the pre-charging circuit configured to pre-charge the bulk capacitor.

Abstract: A circuit and a method for providing a switchable current linkage between a first terminal and a second terminal is presented. The circuit has a transistor switch and a charge pump circuit An output node of the charge pump circuit is coupled to a control terminal of the transistor device, and an input node of the charge pump circuit is coupled to a predetermined voltage. The charge pump generates a boosted voltage. A drive circuit provides feedback control for the current flowing through the transistor. The drive circuit also controls the voltage magnitude at the input node of the charge pump circuit in accordance with the feedback control or to control a magnitude of a voltage at the control terminal of the transistor device in accordance with the feedback control.

Abstract: An embodiment provides a technology of sharing electric charges of two or more flying capacitors in a time interval in which a plurality of flying capacitors are floated, so as to control the charging/discharging balance of the flying capacitors, in a step-up converter.

Abstract: The present subject matter relates to charge pump devices, systems, and methods in which a plurality of series-connected charge-pump stages are connected between a supply voltage node and a primary circuit node, and a discharge circuit is connected to the plurality of charge-pump stages, wherein the discharge circuit is configured to selectively remove charge from the primary circuit node.

Abstract: The power supply apparatus includes an inductor; a switching element connected to another end of the inductor, the switching element configured to drive the inductor by being turned on or turned off in accordance with an input pulse signal; a boost converter circuit connected to both ends of the inductor and including a plurality of rectification units, the boost converter circuit configured to amplify a voltage generated in the inductor, each of the plurality of rectification units including a diode and a capacitor; and a voltage boosting element configured to supply a voltage obtained by boosting an input voltage to the inductor.

Abstract: A voltage control device includes a charge pump, a driving circuit, and a control circuit. The charge pump provides a first voltage. The driving circuit is coupled to the charge pump, and receives the first voltage and a reference voltage. The driving circuit outputs a driving signal according to an input signal, the first voltage and the reference voltage. The control circuit is coupled to the charge pump and the driving circuit. Before the first voltage reaches a threshold level, the control circuit adjusts the reference voltage to increase the voltage gap between the first voltage and the reference voltage.

Abstract: Circuits and methods are provided for soft-starting a switched-capacitor converter (SCC), so as to limit inrush current at the start-up of the SCC. This is accomplished by using the first power switch of the SCC, i.e., the switch coupled to the input of the SCC, to reduce the voltage provided at the SCC input, such that the full input voltage is not directly applied to the SCC circuitry downstream from the first power switch during the SCC start-up. The reduced voltage provided to the SCC circuitry (other than the first power switch) serves to limit the current drawn by the remainder of the SCC circuit during the SCC start-up. This reduced voltage begins at zero and ramps to the voltage provided at the SCC input. Once the reduced voltage reaches the input voltage level, steady-state operation of the SCC may begin.

Abstract: Circuits, devices, and methods for operating a charge pump. In some implementations, a charge pump module includes a clock circuit configured generate to a first clock signal and a second clock signal, the first clock signal having a lower frequency than the second clock signal. The charge pump module also includes a driving circuit configured to generate a first set of clock signals based on the first clock signal and a second set of clock signals based on the second clock signal, the driving circuit coupled to the clock circuit. The charge pump module further includes a charge pump core including a set of capacitances, the charge pump core configured to charge the set of capacitances based the first set of clock signals and the second set of clock signals.

Abstract: To provide a power factor correction circuit capable of maintaining loop gain properly while maintaining current sensing accuracy even when different AC input voltages are input and a switching power source device using the power factor correction circuit. A power factor correction circuit includes: a power factor correction control circuit including an input voltage detection terminal to which voltage corresponding to input voltage to a boost chopper is input, a current sensing terminal to which voltage corresponding to inductor current in the boost chopper is input, an output voltage detection terminal to which voltage corresponding to output voltage from the boost chopper is input, and an output terminal outputting a drive signal for a switching element; and a voltage adjustment circuit configured to detect the input voltage and adjust voltage at the current sensing terminal and voltage at the input voltage detection terminal according to the detected input voltage.

Abstract: A system and method for efficient power, performance and stability tradeoffs of memory accesses under a variety of conditions are described. A system management unit in a computing system interfaces with a memory and a processing unit, and uses boosting of word line voltage levels in the memory to assist write operations. The computing system supports selecting one of multiple word line boost values, each with an associated cross-over region. A cross-over region is a range of operating voltages for the memory used for determining whether to enable or disable boosting of word line voltage levels in the memory. The system management unit selects between enabling and disabling the boosting of word line voltage levels based on a target operational voltage for the memory and the cross-over region prior to updating the operating parameters of the memory to include the target operational voltage.

Abstract: An inductor; a first switch having a first side connected to a first voltage source (VS1); a second switch having a first side connected to a second side of the first switch (2SS1), and a second side connected to a first side of the inductor (1SI); a third switch having a first side connected to the 1SI; a fourth switch having a first side connected to a second side of the third switch (2SS3), and a second side connected to a second voltage source (VS2); a fifth switch having a first side connected to the 1SI, and a second side connected to the VS1 and/or the VS2; a first capacitor having a first side connected to the 2SS1, and a second side connected to the 2SS3; and a second capacitor having a first side connected to a second side of the inductor, and a second side connected to the VS2.

Abstract: The present invention provides a pulse modulating power source, which comprises: a plurality of discharging modules connected in series during discharging; a plurality of triggers corresponding to said plurality of discharging modules, wherein each trigger provides a trigger signal to the corresponding discharging module to turn it on; a control logic module for controlling the trigger signals so as to turn on said plurality of discharging modules successively with a time delay; an output terminal for outputting a voltage.

Abstract: A negative high-voltage generation device with multi-stage selection includes an input, an output, negative charges pumps, electrical switches, and a control device. The negative charge pumps are electrically cascaded between the input and the output and configured to receive zero voltage through the input. The control device turns off at least one of the electrical switches close to the output and turns on the remains of the plurality of electrical switches, and the negative charge pumps and the electrical switches use zero voltage to generate a negative voltage at the output.

Abstract: A charger integrated circuit is provided which includes a DC-DC converter configured to receive an input voltage and generate an output voltage through a switching operation for charging a battery, and a charging controller configured to control the switching operation such that the output voltage is supplied to the battery through charging paths chargeable according to a level of the input voltage.

Abstract: An input-output device includes an input circuit unit including an input-signal-setting storing unit that stores a plurality of ON conditions of the input signal and an input circuit that determines whether any one of the ON conditions of the stored input signal holds, a computing unit including an output-signal-setting storing unit that stores information in which the ON conditions of the input signal, output ports for outputting an output signal, and specifications of the output signal are associated and an output-signal selecting unit that generates, on the basis of a determination result of the input circuit and the stored information, an output command indicating the output ports and the specifications of the output signal, and an output circuit unit including an output circuit that outputs, to the output ports indicated by the output command, the output signal according to the specifications indicated by the output command.

Abstract: A display apparatus is provided. The display apparatus includes a display panel, a chassis configured to support the display panel, a backlight unit configured to be installed on the chassis, and an electricity generator configured to use the backlight unit as a heat source to generate electricity. The electricity generator includes a heat transfer unit which contacts the backlight unit, at least one heat storage unit which contacts the heat transfer unit, and at least one thermoelectric device comprising a heat generator and a heat absorber contacting the heat transfer unit. The at least one thermoelectric device absorbs heat, which is generated from the backlight unit, through the heat transfer unit in response to the backlight unit being driven and absorbs heat from the at least one heat storage unit through the heat transfer unit in response to the backlight unit not being driven.

Abstract: A lens driver or lens driver circuitry for an ophthalmic apparatus comprising an electronic system which actuates a variable-focus optic is disclosed herein. The lens driver is part of an electronic system incorporated into the ophthalmic apparatus. The electronic system includes one or more batteries or other power sources, power management circuitry, one or more sensors, clock generation circuitry, control algorithms and circuitry, and lens driver circuitry. The lens driver circuitry includes one or more power sources, one or more high voltage generators and one or more switching circuits. Specifically, the lens driver comprises an H-bridge/H-bridge controller for providing the proper voltage, including polarity, to drive the electronic included in the ophthalmic apparatus.

Abstract: A voltage multiplier circuit operates in response to a received clock signal to perform a voltage multiplication operation on an input voltage to generate an output voltage. The voltage multiplier circuit includes a pair of intermediate nodes that are capacitively coupled to receive, respectively, opposite phases of a clock signal. A first CMOS driver circuit is coupled to one of the intermediate nodes and has an output configured to generate one phase of a level shifted output clock signal. A second CMOS driver circuit is coupled to another one of the intermediate nodes and has an output configured to generate another phase of the level shifted output clock signal.

Abstract: A driver circuit for an electronic display, including a power supply system configured to provide a reference voltage, a DC-DC converter having an input connected to the power supply system and having at least a first output configured to provide a first driving voltage, a second output configured to provide a second driving voltage and a third output configured to provide a third output voltage, wherein the second output voltage is higher than the first output voltage and wherein the third output voltage is higher than the second output voltage, wherein the DC-DC converter includes at least a first charge pump, and wherein the input is directly connectable to the second output to provide the reference voltage as the second output voltage.

Abstract: The present disclosure is directed to a plurality of waffle gate parallel transistors having a shared gate on a surface of a semiconductor substrate. The shared gate has connected channels that form a plurality of squares, lines of each of the squares over the perimeter of a respective source or drain region of the plurality of waffle gate parallel transistors. The shared gate includes squares of a first size and shape and a second size and shape. The squares having the first size and shape are each over a respective source region and the squares having the second size and shape are each over a respective drain region. Each of the squares having a first size and shape share at least one side with one of the squares having the second size and shape.

Abstract: A switched capacitor DC-DC convertor circuit and a production method thereof are described. The switched capacitor DC-DC convertor circuit includes two switched-capacitor circuits each including at least one capacitor, multiple internal switches and the same circuit layout. The internal switches of the two switched-capacitor circuits corresponding in position to each other are controlled by different control signals, and the turn-on durations of the control signals do not overlap. The capacitors of the two switched capacitor circuits are connected by an interconnection switch, and a turn-on duration of a control signal for the interconnection switch also does not overlap with that of the control signals for the internal switches. The switched capacitor DC-DC convertor circuit has a lower switching power loss compared to current state of the art.

Abstract: In described examples, a DC-DC converter provides electrical power. The converter includes an inductor and a flying capacitor. In response to an input voltage transitioning from below a normal operation threshold to above the threshold, a first transition phase and a second transition phase are repeatedly performed. The first transition phase comprises coupling an input terminal of the inductor to a ground, and the second transition phase comprises delivering power through the inductor by discharging the flying capacitor through the inductor. After the input voltage is above the normal operation threshold, and a voltage across the flying capacitor has reached a target voltage proportional to the input voltage, a charging phase, a freewheeling phase and a discharging phase are repeatedly performed. The charging phase comprises charging the flying capacitor by coupling the flying capacitor to the input voltage, and delivering current from the input voltage through the inductor.