Abstract: A method of controlling a power factor correction (PFC) converter that has a discontinuous input current includes sensing the input current, sensing an output voltage and controlling a duty cycle of at least one switch in the converter in response to the sensed input current and output voltage using a control equation for controlling the duty cycle of the switch such that an average input current to the converter is sinusoidal. Example circuits capable of performing the method are also disclosed.

Abstract: A phase control apparatus includes a first transistor whose source or emitter is connected to one end of an AC power supply and whose drain or collector is connected to one end of a load, a second transistor whose source or emitter is connected to the other end of the AC supply and whose drain or collector is connected to the other end of the load, a diode bridge that rectifies an AC voltage of the AC supply, and a parallel circuit of a zener diode and a capacitor. The parallel circuit generates a high potential relative to a bridge negative output terminal potential, or generates a low potential relative to a bridge positive output terminal potential. First and second transistor control terminal potentials are switched between the high and the bridge negative output terminal potentials, or between the low and the bridge positive output terminal potentials.

Abstract: A control circuit for a buck-boost circuit includes an inductor current sensor and an input current generator. The input current generator accepts a signal from the inductor current sensor and outputs a synthesized and integrated signal representing the average input current to the buck-boost circuit. The input current generator averages the inductor current signal or a zero signal based on the state of the buck switch in the buck-boost circuit.

Abstract: The present invention includes: a main switch Tr1 connected to two ends of a DC power supply Vi via a first primary winding 1a and a second primary winding 1b, connected to the first primary winding in series, of a transformer T1; a series circuit connected to the two ends of the main switch, and including a reactor L1, a diode D1, a smoothing capacitor Co and a hoist winding 1c connected to the second primary winding in series; a series circuit connected to the two ends of the main switch, and including a diode D2, a diode D3 and the smoothing capacitor; a control circuit 10 to turn on and off the main switch; a soft-switching circuit Da1, Tra1, La1, Ca1 to cause the main switch to perform a soft-switching operation each time the main switch turns on; and a switching control circuit 20 to switch the soft-switching circuit between operating and non-operating modes in accordance with the state of a load.

Abstract: An apparatus, device, and system for generating an amount of output power in response to a direct current (DC) power input includes a configurable power supply, which may be electrically coupled to the DC power input. The configurable power supply is selectively configurable between multiple circuit topologies to generate various DC power outputs and/or and AC power output. The system may also include one or more DC power electronic accessories, such as DC-to-DC power converters, and/or one or more AC power electronic accessories such as DC-to-AC power converters. The power electronic accessories are couplable to the configurable power supply to receive the corresponding DC or AC power output of the configurable power supply.

Abstract: Consistent with an example embodiment, a circuit comprises a power factor correction stage having a DC input, a ground input, a DC output and a ground output. The circuit further includes a capacitor; a diode; and a discharge circuit. A first terminal of the diode is connected to an input of the power factor correction stage, a second terminal of the diode is connected to the first plate of the capacitor; and the second plate of the capacitor is connected to the other input of the PFC stage. The discharge circuit is connected to the capacitor and is configured to discharge the capacitor such that it contributes to the output of the PFC stage when the level of a signal at the input of the PFC stage falls below a threshold value.

Abstract: A boost circuit is used for power factor correction (PFC). In a low power application, transition mode control is utilized. However, switching frequency varies with different input voltages, and over a wide input voltage range, the switching frequency can become too high to be practical. To address this issue, a boost circuit is provided whose effective inductance changes as a function of input voltage. By changing the inductance, control is exercised over switching frequency.

Abstract: A stable, high-speed, high-efficiency constant voltage is provided without a complicated, large-scale, high-cost phase compensation circuit over a wide range of operating conditions. This voltage buck-boost switching regulator consists of a pair of voltage reducing transistors, a pair of voltage boosting transistors, inductance coil, output capacitor and controller. The controller has the following parts for performing PWM control of constant voltage for voltage reducing transistors and voltage boosting transistors: an output voltage feedback circuit, an inductor current sense circuit, a variable sawtooth wave signal generator, switching controllers, and a voltage boosting driver.

Abstract: In a buck-boost converter, the method compensates for the boost mode power switch having a minimum on-time when entering the buck-boost mode from the buck mode by immediately decreasing a duty cycle of the buck mode power switch upon entering the buck-boost mode. This prevents the inductor current from being higher at the end of the switching cycle than at the beginning of the cycle, so the output voltage stays regulated without the converter oscillating between the buck mode and the buck-boost mode. The duty cycle of the buck power switch is increased in the buck-boost mode as the input voltage further falls and the boost power switch duty cycle is increased. Upon transitioning into the boost mode, the duty cycle of the boost power switch is immediately reduced to compensate for the buck switching being stopped and the buck power switch having a minimum off-time.

Abstract: A PWM controller for adjusting an output voltage of a buck and boost converter includes a first saw wave generator, which generates a first saw wave in accordance with the level of the output voltage. A first comparator coupled to the first saw wave generator compares the first saw wave with a first reference voltage and generates a first pulse. A peak hold circuit coupled to the first saw wave generator holds a peak value of the first saw wave. A second saw wave generator coupled to the peak hold circuit generates a second saw wave having a lower limit value that is the peak value of the first saw wave. A second comparator coupled to the second saw wave generator compares the second saw wave with the first reference voltage and generates a second pulse.

Abstract: The present invention discloses an adaptive voltage position DC-DC regulator and the method thereof, the regulator comprising a main circuit and a control circuit which includes a sensing unit, a feedback unit, a comparing unit, a PWM generator and a driver. The regulator realizes the adaptive voltage position control with simple internal circuit and fewer pins.

Abstract: A high voltage generation circuit for laser puncture in which the voltage for laser puncture can be boosted up to the laser oscillation level in a short time with low power loss. The high voltage generation circuit drives a laser unit for puncturing the skin by oscillating laser light. In the high voltage generation circuit, a capacitor is charged to supply power to the laser unit. A booster circuit supplies a current to the capacitor, and a voltage measurer measures the voltage of the capacitor. A controller controls the booster circuit based on an instruction from a user or the voltage of the capacitor to start precharge of the capacitor with a first current value at a first timing, and to start main charging of the capacitor with a second current value higher than the first current value at a second timing, later than the first timing.

Abstract: A buck-boost converter with a switch controller may cause switches A, B, C, and/or D to cyclically close such that switches B and C are closed during at least one interval of each cycle during both the buck and boost modes of operation. The switch controller may in addition or instead cause switches A, B, C, and/or D to cyclically close based on a control signal such that switches A and D are closed during an interval of each cycle and such that these intervals are never both simultaneously modulated by a small change in the control signal during any mode of operation.

Abstract: A control circuit includes a controller that provides a master PWM signal indicative of a difference between a predetermined setpoint and a process signal. The control circuit also includes a PWM splitter circuit that receives the master PWM signal and provides a first PWM signal for a first switch and a second PWM signal for a second switch. The first PWM signal corresponds to a first portion of the master PWM signal and the second PWM signal corresponds to a second portion of the master PWM signal.

Abstract: In one embodiment, each of a plurality of sites may produce surplus power. All or a fraction of the surplus power may be supplied to the power grid according to an agreement between the user of a site and an electric utility. A computer of the utility is in communication with a computer at each of a plurality of sites having a local power source. Terms of power provision that include an amount of power to be provided during a specified time of day is communicated between a site and the utility.

Abstract: A converter controller for discharge of a coil used in a DC/DC converter including a voltage detector connected to monitor a state of a diode connected between the coil and ground and an offset comparator, having an adjustable offset, for causing a coil discharge path to be interrupted. The comparator is provided with an initial high offset so that for at least a first converter switching period, the coil will have sufficient charge when the coil discharge path is interrupted to cause the diode to become forward biased as determined by the voltage detector. The offset is periodically reduced until the coil is sufficiently discharged so that the diode is not forward biased, with that value of offset being optimum and thus used in subsequent switching periods.

Abstract: A power conversion circuit for decentralizing input current includes a capacitor, a first inductor, a first switching circuit, a first discharging circuit, a second inductor, a second switching circuit, a second discharging circuit, and a control circuit. Under control of the control circuit, the first switching circuit and the second switching circuit are alternately conducted, and the second switching circuit is successively conducted when the first switching circuit is shut off.

Abstract: A non-inverting buck boost voltage converter includes a buck boost voltage regulation circuitry for generating a regulated output voltage responsive to an input voltage. A current sensor monitors an input current to the buck boost voltage regulation circuitry. Buck boost mode control circuitry controls the buck boost voltage regulation circuitry using peak current mode control in a buck mode of operation and valley current mode control in boost mode of operation responsive to the monitored input current.

Abstract: A buck/boost regulator controller is provided. The buck-boost regulator controller controls four switches in an H-bridge configuration to control voltage regulation. The buck/boost regulator controller includes a digital error amplifier and buck-boost control logic. The digital error amplifier provides a multi-bit digital error voltage signal that is based on the difference between the output voltage and the desired output voltage. The buck-boost control logic controls the opening and closing of the four switches in the H-bridge based, in part, on the multi-bit digital error voltage signal.

Abstract: [Task] A high-speed driving is possible, a utilization of a power supply having a low voltage is possible, and a regeneration is easy to be carried out. [Means to solve the task] A first buck-boost chopper portion is provided on an output side of a battery 10 to boost a voltage across battery 10 during a drive of a motor, a second buck-boost chopper portion is provided on an output side of the first buck-boost chopper portion to boost the voltage from an inverter portion 20 during a regeneration, inverter portion 20 of a 120-degree conduction current source inverter is provided on the output side of the second buck-boost chopper portion, and a motor 38 is provided on an output side of inverter portion 20.

Abstract: The present invention relates to a single-stage zero-current switching driving circuit for ultrasonic motor, which comprises: a buck-boost converter and a zero-current switching resonant inverter. The driving circuit according to the present invention integrates the buck-boost converter and the resonant inverter into a single-stage structure, so that the buck-boost converter and the resonant inverter share an active switch and a trigger signal, and therefore, the circuit is simplified and the loss caused by stage switching is reduced. Moreover, the buck-boost converter operates in a discontinuous-conduction mode (DCM), which allows the circuit to have high power factor, and enables the active switch to be capable of zero-current switching (ZCS), so that the loss caused by switching is largely reduced. In the driving circuit according to the present invention, there's no interaction of power between the buck-boost converter and the resonant inverter, so that the two circuits can be analyzed individually.

Abstract: A power supply system has an inductive device, a plurality of switching devices for providing connection of the inductive device to input and output nodes and a ground node, and a switch driver circuit for driving the switching devices so as to enable the power supply to operate in a boost mode to increase the input voltage, in a buck mode to decrease the input voltage, and in a solid-state flyback mode to transfer between the boost mode and the buck mode. In the solid-state flyback mode, the switching devices are controlled to provide switching of the inductive device between an input state in which the inductive device is connected between the input node and the ground node, and an output state in which the inductive device is connected between the ground node and the output node.

Abstract: A method for DC/DC conversion which comprises the steps of controlling a first switch (10) for coupling a supply terminal (5) to a first terminal (60) of an inductor (2) and a second switch (20) for coupling the first terminal (60) to a ground potential terminal (8). The method further comprises controlling a third switch (30) for coupling a second terminal (61) of the inductor (2) to the ground potential terminal (8) and a fourth switch (40) for coupling the second terminal (61) to an output terminal (6). A control sequence is used to control the four switches (10, 20, 30, 40) using four switching phases (A, B, C, D). A maximum of two switches out of the four switches (10, 20, 30, 40) change their switching position at a respective transition of subsequent switching phases (A, B, C, D).

Abstract: The DC-DC converter includes a control unit that controls a current stored in an inductance and an output voltage output from an output terminal electrically couplable to the inductance. The control unit assigns a first period and a second period to a given period when the output voltage is lower than a given value in response to a load electrically couplable to the output terminal. The first period is where a current is stored in the inductance in response to an input voltage and a reference voltage, and the second period is where the current stored in the inductance is supplied to the output terminal in response to the input voltage and the output voltage.

Abstract: A DC-DC converter has a first-voltage-side port, a second-voltage-side port, and a third-voltage-side port, and performs, at different timings, an operation of boosting a first voltage to a third voltage and an operation of bucking a second voltage to the third voltage. A power supplying system includes a fuel cell, a secondary battery, an accessory system, the DC-DC converter, and another DC-DC converter connected between the fuel cell and a motor, and boosting the first voltage of the fuel cell to a fourth voltage to supply power to the motor through an inverter. The former DC-DC converter has the first-voltage-side port connected to the fuel cell, has the second-voltage-side port connected to the secondary battery, and has the third-voltage-side port connected to the accessory system.

Abstract: A switching regulator is provided that includes a step-down circuit configured to output a voltage lower than an input voltage, a step-up circuit configured to output a voltage higher than the input voltage, and a control unit having a voltage detector configured to detect an output voltage and being configured to prohibit operation of the step-up circuit until the output voltage rises to a first voltage lower than the input voltage.

Abstract: A chopper type DC-DC converter includes a voltage converting circuit, a comparative wave generating circuit, a comparator group, and a switch control circuit. The voltage converting circuit converts a first voltage into a second voltage. The comparative wave generating circuit generates first and second comparative waves such that the voltage range of the first comparative wave is different from the voltage range of the second comparative wave. The comparator group generates a first comparison result signal indicating a result of comparison between the first comparative wave and an error signal indicating an error between the second voltage and target voltage and a second comparison result signal indicating a result of comparison between the second comparative wave and the error signal. The switch control circuit controls the voltage converting circuit based on the first and second comparison signals. The comparative wave generating circuit includes first and second comparative wave generating circuits.

Abstract: An apparatus, device, and system for generating an amount of output power in response to a direct current (DC) power input includes a configurable power supply, which may be electrically coupled to the DC power input. The configurable power supply is selectively configurable between multiple circuit topologies to generate various DC power outputs and/or and AC power output. The system may also include one or more DC power electronic accessories, such as DC-to-DC power converters, and/or one or more AC power electronic accessories such as DC-to-AC power converters. The power electronic accessories are couplable to the configurable power supply to receive the corresponding DC or AC power output of the configurable power supply.

Abstract: A voltage boosting/lowering circuit in accordance with present invention includes an output voltage generation circuit including a first switch element connected between an input terminal and one end of a choke coil and a second switch element connected between the other end of the choke coil and a ground terminal, the output voltage generation circuit being configured to boost or lower an input voltage input to the input terminal and thereby to generate an output voltage by switching the first and second switch elements between an On-state and an Off-state. Further, voltage boosting/lowering circuit includes a clock generation circuit that generates voltage-boosting and voltage-lowering clocks having different timings, and a switch control unit that performs switching control of the first and second switch elements based on the voltage-boosting and voltage-lowering clocks so that negative feedback control is performed so as to bring the output voltage to a target output voltage.

Abstract: A method of controlling an uninterruptible power supply apparatus (UPS) is provided. The UPS apparatus includes at least an AC input voltage, a DC input voltage and a single-phase AC/AC converter. The single-phase AC/AC converter includes an AC inductor, a bus capacitor, a boost arm, a common arm and a buck arm. The method includes steps of: controlling the bus voltage to have a DC component and full-wave rectifying component, and setting a bus voltage parameter K so that the bus voltage approaches to a full-wave rectifying voltage when K approaches to 1, wherein 0?K?1.

Abstract: A buck converter for use in controlling a motor in accordance with an embodiment of the present invention includes a power input operable for connection to a DC power supply, a switch for selectively connecting the motor to the power supply, a pulse width modulation controller operable to provide a pulse width modulation signal to the switch, wherein the switch connects the motor to the power supply based on the pulse width modulation signal, and a voltage shifting capacitor connected across the switch and in series with a diode. The buck converter may include a shift control device operable to control a voltage across the voltage shifting capacitor.

Abstract: A lamp driver circuit for operating a gas discharge lamp (La) is proposed, which comprises a switched mode power supply circuit (SMPS) and a first and a second output terminal (OT1, 0T2) for supplying a lamp current to the gas discharge lamp (La). The lamp driver circuit further comprises an output capacitor (CO) connected between the SMPS circuit and a ground terminal (GT) and comprises a resistive shunt (Rsh) connected between the ground terminal (GT) and the second output terminal (0T2) for determining the lamp current. An output current sensing circuit for determining a SMPS output current is comprised in the lamp driver circuit instead of a further resistive shunt, which would require a differential voltage measurement. The output current sensing circuit comprises a sensing resistor (RS) connected in series with a sensing capacitor (CS), the series connection being connected in parallel to the output capacitor.

Abstract: A power management apparatus includes a first electrical lead and a second electrical lead. The first electrical lead routes electrical current at a first electrical lead electrical potential level and the second electrical lead route electrical current at a second current port electrical potential level. The power management apparatus further includes a first electrical parameter sensor configured to measure a first electrical lead electrical parameter and a second electrical parameter sensor configured to measure a second electrical lead electrical parameter. The power management apparatus further comprises a buck boost converter electrically coupled to both the first electrical lead and the second electrical lead. The buck boost converter is configured to convert electrical current between the first electrical lead electric potential level and the second electrical lead electric potential level at a controlled potential conversion level.

Abstract: A buck (with boost) switcher is provided that adds boost functionality to a buck switcher without compromising the buck's performance with extra series-coupled switches nor requiring a second inductor. The switcher has an integrated circuit that is capable of receiving a power supply voltage and a mode signal and generating on separate outputs either a boost voltage or a buck voltage based on the power supply voltage and the mode signal. The mode signal corresponds to one of a buck mode and a boost mode. The switcher also has a single inductor that is coupled to the integrated circuit and is capable of being used by the integrated circuit to generate the boost voltage (or a high voltage capable current) in the boost mode and to generate the buck voltage in the buck mode.

Abstract: A method of controlling a DC/DC converter to regulate an output voltage from an input voltage source that varies from a fully-charged voltage to a discharged voltage. The method introduced improves the dynamic response of the converter during transients by switching between different converter topologies to spread out voltage spikes, which are an inevitable result of transients. The invention also can improve the efficiency of the DC/DC converter by replacing higher loss modes with combination modes.

Abstract: A boost regulator for converting an input voltage to a higher output voltage including an inductor, an error circuit, a switching circuit, a ripple circuit, and a hysteretic comparator circuit. The inductor has a first end coupled to the input voltage and a second end. The error circuit determines an error of the output voltage and provides an error voltage indicative thereof. The switching circuit switches the second end of the inductor between the output voltage and ground as controlled by a pulse width modulation signal. The ripple circuit synthetically replicates ripple current through the inductor based on voltage applied across the inductor and provides a ripple voltage indicative thereof. The hysteretic comparator circuit develops the pulse width modulation signal based on comparing the ripple voltage within a hysteretic window voltage range based on the error voltage.

Abstract: A buck-boost regulator for converting an input voltage to an output voltage which includes an inductor, an error circuit providing an error voltage, buck and boost switching circuits, buck and boost ripple circuits, and buck and boost hysteretic comparator circuits. The buck switching circuit switches a first end of the inductor, the buck ripple circuit replicates ripple current through the inductor based on the buck pulse signal and provides a buck ripple voltage, and the buck hysteretic comparator circuit develops the buck pulse signal based on a buck window voltage range using the error voltage. The boost switching circuit switches a second end of the inductor, the boost ripple circuit replicates ripple current through the inductor based on the boost pulse signal and provides a boost ripple voltage, and the boost hysteretic comparator circuit develops the boost pulse signal based on a boost window voltage range using the error voltage.

Abstract: To provide a control circuit and control method of a step-up/step-down type DC-DC converter capable of realizing high efficiency. In a state (1), a terminal Tx of a choke coil L1 is connected to an input terminal Tin, and a terminal Ty is connected to a reference potential. In a state (2), the terminal Tx is connected to the reference potential, and the terminal Ty is connected to an output terminal Tout. In the state (3), the terminal Tx is connected to the input terminal Tin, and the terminal Ty is connected to the output terminal Tout. A first period operation TO1 is constituted by the states (1) and (2), and a second period operation TO2 is constituted by the states (1) and (3). A second period T2, in which the second period operation TO2 is performed, is a value n times as long as a first period T1, in which the first period operation TO1 is performed. In the second period operation TO2, the state (1) is switched to the state (3) so that an increasing slope of an inductor current IL is reduced.

Abstract: Methods and apparatus are disclosed for efficient switching regulators that adapt automatically to, and operate with, input voltages that are above, below, or equal to the output voltage. The disclosed switching regulators demonstrate advantages of both buck and boost converters at high efficiency.

Abstract: Unlike buck converter and tapped-inductor buck converters, which use only inductive energy transfer, the present invention employs the capacitive energy transfer in addition to inductive energy transfer. The hybrid transformer performs the double duty simultaneously: transfers the input inductive energy storage to the load through a taped-inductor turns ratio n but also transfers the resonant capacitor discharge current to the load during OFF-time interval amplified by turns ratio m of the hybrid transformer. Despite the presence of the resonant inductor current during the OFF-time interval, the output voltage is neither dependent on resonant component values nor on the load current as in conventional resonant converters but depends on duty ratio D and turns ratio n of the hybrid transformer. Hence a simple regulation of output voltage is achieved using duty ratio control.

Abstract: A current-mode controlled DC-DC converter includes a comparator comparing a first or second current detection signal with a first or second reference current that is based on an error voltage of a voltage detection signal, a pulse generator generating a first pulse signal whose ON time is longer than an interval between when the second current detection signal reaches a minimum value and when the second current detection signal reaches the second reference current, a pulse generator generating a second pulse signal whose ON time is longer than an interval between when the first current detection signal reaches a minimum value and when the first current detection signal reaches the first reference current, the second pulse signal being behind the first pulse signal by a half period, and a PWM circuit generating a first or second PWM signal according to the pulse signal and an output signal from the comparator, thereby turning on/off a switch.

Abstract: A buck or boost converter, which includes a first inductor, a controlled switch, a main diode, and an output capacitor, also includes a snubber circuit to reduce losses. The snubber circuit includes a second inductor in a path in series with the switch and main diode of the converter, a series-connected resistor and diode connected directly in parallel with the second inductor, and a capacitance in parallel with the main diode and which can be constituted partly or entirely by parasitic capacitance of the main diode.

Abstract: A switching power converter includes an input terminal for receiving an input voltage, an output terminal for supplying an output voltage, a coupled choke having a main winding and an auxiliary winding, an output capacitor coupled to the output terminal, a main diode coupled between the auxiliary winding and the output terminal, and a switch having first and second positions. The main and auxiliary windings are connected to be charged by an input voltage when the input voltage is coupled to the input terminal and the switch is in the first position. The auxiliary winding is connected to reverse bias the main diode when the switch is switched from the first position to the second position to thereby suppress reverse recovery current in the main diode. The power converter may further include an auxiliary diode coupled between a common node of the main and auxiliary windings and the output terminal, as well as an inductor in series with the auxiliary diode.

Abstract: A method of and system for modulating buck and boost modulation ramps of a multiple switch node power converter without overlap. As the pulse width or duty cycle of the signal to a modulated complementary switching pair approaches a pre-established reference pulse width or duty cycle, plural fixed-width or fixed duty cycle pulses are generated and introduced to a nonmodulated complementary switching pair. A controller detects proximity to the pulse width or duty cycle limit and, correspondingly, initiates prematurely a pseudo-buck-boost mode in the power converter by generating fixed-width or fixed duty cycle pulses to the nonmodulated complementary switching pair while the duty cycles or pulse widths to the modulated complementary switching pair are still controlled by the appropriate modulation ramp. The net effect is that the power converter reaches its optimal operating point without overlap and eliminates any sub-harmonic switching.

Abstract: In a buck-boost converter, the method compensates for the boost mode power switch having a minimum on-time when entering the buck-boost mode from the buck mode by immediately decreasing a duty cycle of the buck mode power switch upon entering the buck-boost mode. This prevents the inductor current from being higher at the end of the switching cycle than at the beginning of the cycle, so the output voltage stays regulated without the converter oscillating between the buck mode and the buck-boost mode. The duty cycle of the buck power switch is increased in the buck-boost mode as the input voltage further falls and the boost power switch duty cycle is increased. Upon transitioning into the boost mode, the duty cycle of the boost power switch is immediately reduced to compensate for the buck switching being stopped and the buck power switch having a minimum off-time.

Abstract: This disclosure relates to a voltage regulator system where duty cycle value of an input voltage is measured, where the input voltage is supplied to a regulator circuit that provides a regulated output voltage. Based on a calculated ideal duty cycle, which is derived from the measure duty cycle, a determination is made as to whether the regular circuit operational mode is to be changed to achieve greater efficiency.

Abstract: A switching power supply includes: a first switch provided between one end of a DC power supply and one end of a load; a second switch provided between a node of the first switch located on a load side and another end of the DC power supply; a capacitor provided between the second switch and the another end of the DC power supply; a third switch provided between a node of the first switch located on a DC power supply side and a node between the second switch and the capacitor; and a delay circuit that is provided between the third switch and the node between the second switch and the capacitor and delays a current for charging the capacitor, wherein the second switch is turned on in a period during which the first switch is kept on.

Abstract: In one embodiment, a power supply controller is configured to operate a plurality of switches in a buck-boost mode to control an output voltage wherein at least one switch of the plurality of switches is enabled for a substantially fixed portion of a cycle of the buck-boost mode.

Abstract: A high efficiency control circuit for operating a switching regulator is provided. The switching regulator can regulate an output voltage no matter the input voltage is higher, lower, or close to the output voltage. The switching regulator has first, second, third and fourth switches. The control circuit can operate the switching regulator in buck mode, boost mode, or buck-boost mode. In a buck-boost mode, the control logic drives the four switches in an efficiency sequence for reducing energy consumption during the switch transition, on the other side, resistive loss owing to the energy transfer phase is also minimized. Furthermore, the invention is capable of control duty cycle limitation to fit the consideration of the linearity of the converter.

Abstract: According to an exemplary embodiment, a method includes the step (910) of driving a buck section of a DC/DC converter with a buck signal that has a buck duty cycle and concurrently with driving the buck section, driving a boost section of the DC/DC converter with a boost signal that has a boost duty cycle, a difference existing between the buck duty cycle and the boost duty cycle. The method also includes the step (920) of monitoring an input voltage that is coupled to the buck section for a change in the input voltage, and in response to a change in the input voltage, the step (930) of changing the buck duty cycle and the boost duty cycle such that the difference between the buck duty cycle and the boost duty cycle is substantially constant.