Abstract: A power converter includes a bypass circuit connected in parallel with a power stage of the power converter. The bypass circuit provides a lower loss current path in parallel with the power stage when an input voltage of the power converter exceeds a predetermined threshold. The power converter may be a boost power converter used in a vehicle to provide power from a main power bus of the vehicle to a subsystem of the vehicle such as an anti-lock brake system.

Abstract: Disclosed is an interleaved power converter for converting a DC voltage source into a DC voltage output.

Abstract: There is provided an interleaved type power factor correction circuit having a transformer forming a separated winding structure, which is formed by integrating two inductors separately wound around the transformer. The interleaved type power factor correction circuit including a rectifying unit rectifying a commercial alternating current power, a transformer having a first inductor winding and a second inductor winding, a bobbin part, and a core part, a switching unit switching a power transmitted to the first and second inductor windings, a controlling unit controlling a switching operation of the switching unit in order to allow a phase difference between a current and a voltage of the switched power to satisfy a predetermined phase difference, and a stabilizing unit stabilizing the switched power from the switching unit.

Abstract: A current-control profile may be built from a sequence of phases in which the current is controlled in a defined manner. The electrical behavior of these phases may be configured within a list, which contains one entry, or slot, for each phase and which may be stored in a memory device. The order for stepping through the list is not hard-wired into the control circuit. Instead, such an order is part of the configuration for each entry, or slot, itself. Each entry/slot contains the information about the next phase, or the next possible phases depending upon the occurrence of any trigger events. In this way, the list of entries/slots is linked dynamically by the configuration thereby allowing for generation, in a flexible way, of current profiles with different characteristics and different numbers of phases and sequences.

Abstract: A constant current source circuit is constituted of a control voltage generation section which detects the output voltage at the output terminal so as to generate a control voltage, a reference current adjustment section which adjust a reference current based on the control voltage, and a current mirror section which outputs the output current responsive to the adjusted reference current at the output terminal. This reduces variations of the output current due to variations of the output voltage; hence, the constant current source circuit can precisely operate in a low-voltage region.

Abstract: A solar photovoltaic plant is disclosed where a number of distributed DC-to-DC converters are used in conjunction with a central DC-to-AC converter. Each DC-to-DC converter is dedicated to a portion of the photovoltaic array and tracks the maximum power point voltage thereof. The DC-to-DC converters also boost the photovoltaic voltage and regulate a DC output current for transmission to the central DC-to-AC converter. Five distinct advantages are had over the prior art. First, efficiencies in intra-field power collection are greatly improved by transferring power at higher DC voltages. Second, the number of independent photovoltaic maximum power point trackers in the power plant can be increased, in a cost effective manner, to optimize the overall photovoltaic array energy harvest. Third, each DC-to-DC converter output “looks” like a current source at the input of the DC-to-AC converter and therefore can be easily paralleled.

Abstract: Method and system for load sharing in a multiple power supply system. At least some of the illustrative embodiments are power supply units including a switching circuit, a coarse adjustment circuit coupled to the switching circuit (the coarse adjustment circuit configured to send an internal command to the switching circuit to modify a pulse width modulated signal that controls output current of the power supply unit), and a communication port coupled to the switching circuit. The power supply unit configured to receive from an external device over the communication port an external command to modify the pulse width modulated signal of the switching circuit. The power supply unit is also configured to modify the output current, the amount of modification based on the external command, and the internal command from the coarse adjustment circuit.

Abstract: A circuit for driving a gate of a power MOS transistor includes an adaptive pull-up unit and an adaptive pull-down unit. The adaptive pull-up unit is connected between a first power source voltage and the gate of the power MOS transistor. The adaptive pull-up unit maximizes pull-up current driving ability. The adaptive pull-down unit is connected between a second power source voltage and the gate of the power MOS transistor. The adaptive pull-down unit maximizes pull-down current driving ability.

Abstract: A multiphase switching regulator includes a power stage with at least a first phase and a second phase for supplying power to a load through inductors coupling the phases to the load. The multiphase switching regulator is operated by switching the first phase at a higher switching frequency than the second phase via pulse width modulation (PWM) signals provided to the phases. A phase-specific target current is generated for each phase at the switching frequency for that phase based on the difference between an output voltage of the power stage and a reference voltage. The current in the inductors coupling the phases to the load is sensed, and a duty cycle of the PWM signal provided to each phase is adjusted based on the phase-specific target current and sensed inductor current for that phase.

Abstract: A novel method to operate synthetic ripple multi-phase switching power converters at constant frequency is presented. The method includes the means for sensing the current in each phase without adding extra dissipation and for balancing the currents by affecting the synthetic ripple signal to modulate the duty cycle without disturbing the overall output voltage regulation. Furthermore a method for obtaining optimum load transient response is presented. The method includes the means for simply determining the derivative of the synthetic ripple signal and for forcing maximum duty cycle until the derivative of the synthetic ripple signal reaches a certain threshold. A variant of this method improves further the load transient response by coupling an RC network to the ramp signal generated to modulate the duty cycle so as to maintain the maximum duty cycle a bit longer after the derivative of the synthetic ripple signal has reached the zero value.

Abstract: The invention discloses a voltage regulating apparatus, which includes: a linear regulator generating a first error signal; a switching regulator generating a first and a second PWM signals; a selecting unit coupled to the linear and switching regulators, receiving the first error signal and the second PWM signal, and outputting a regulating signal; a first power transistor coupled to the switching regulator and receiving the first PWM signal; and a second power transistor coupled to the selecting unit and receiving the regulating signal; wherein the voltage regulating apparatus can be put either in a linear mode of operation if the first error signal is selected as the regulating signal, or in a switching mode of operation if the second PWM signal is selected as the regulating signal.

Abstract: A switching power-supply apparatus and a switching power supply circuit in which a feedback signal is input from a feedback circuit to a feedback terminal of a switching control IC includes a capacitor and a Zener diode connected between the feedback terminal and a ground terminal. The Zener diode is a selectively connected external circuit. A voltage of the feedback terminal during an overcurrent operation changes depending on whether or not the external circuit is present. A return/latch determination circuit detects the voltage of the feedback terminal to switch between an automatic return system and a latch system in an overcurrent operation state.

Abstract: A power factor correction stage comprising: an input terminal configured to receive an input signal; an output terminal configured to provide an output signal; a first converter stage and one or more further converter stages, wherein each of the converter stages is connected to the input terminal and the output terminal, and each converter stage comprises a switch; and a controller configured to operate the switches of the converter stages. The controller is configured to operate the switch of the one or more further converter stages at a period of time after operation of the switch of the first converter stage for a current switching cycle, wherein the period of time corresponds to a proportion of the switching frequency for an earlier switching cycle that does not correspond to substantially the period of the earlier switching cycle divided by the number of converter stages.

Abstract: The switched-mode power supply includes a switching cell having an inductive element with two connections and several individually selectable outputs, and in which the two connections of the inductive element are joined respectively to at least two of the individually selectable outputs. It is thus possible to generate and regulate at least two different voltages, one positive and one negative.

Abstract: An object is to miniaturize booster coils used in a vehicle-mounted booster converter. In the design method for a vehicle-mounted multi-phase converter including multiple booster coils and a switching circuit for generating an induced electromotive force at each booster coil by switching of current flowing to each booster coil for applying an output voltage, based on an input voltage and the induced electromotive force generated at each booster coil, to a vehicle drive circuit, a coupling factor indicating the extent by which the induced electromotive force in one of multiple booster coils contributes to the voltage between terminals of another booster coil is determined on the basis of a relationship between the coupling factor and current ripple component of each booster coil.

Abstract: A power regulation circuit is connected to a voltage supply unit for receiving a power-on voltage supplied by the voltage supply unit and to a voltage management unit for enabling an enable port thereof. The power regulation circuit includes a first regulation unit and the second regulation unit. The first regulation unit is used for outputting an enable signal to the enable port when the power-on voltage is lower than a threshold value such that the voltage management unit can output a first working voltage to a load via a first output port thereof. The first regulation unit stops outputting the enable signal after the expiry of a certain period of time following the drop in a power supply to a level which is below a certain threshold value for a predetermined period.

Abstract: A method of balancing current supplied by a plurality of regulators coupled to a load includes: measuring an average load current supplied by each regulator; determining an overall average current to be shared by the plurality of regulators; comparing each average load current with the overall average current to be shared by the plurality of regulators; and adjusting an output current of one or more of the plurality of regulators so that the plurality of regulators supply the same current to the load.

Abstract: Methods and apparatus for a multiphase power regulator according various aspects of the present invention operate in conjunction with an active transient response (ATR) system for applying a correction signal to a multiphase pulse width modulator. In the event of a transient, the ATR system may adjust the output of the pulse width modulator to quickly respond to load requirements. The output may be modified by adding pulses, blanking pulses, advancing pulses, and scaling pulses to one or more phases.

Abstract: A power supply apparatus includes a first output power circuit, a first output protection circuit, a first output capacitor, a first pre-charging circuit and a first power supply control circuit. The first output power circuit is used for generating a first internal output voltage. The first output protection circuit is connected to a power output terminal of the first output power circuit for limiting the current direction. The first pre-charging circuit is interconnected between a power input terminal and a power output terminal of the first output protection circuit for providing a first pre-charging path. When the first power-on signal is switched from a disabled status to an enabled status, a first pulse width modulation signal having a higher or the maximum duty cycle is transmitted from the first power supply control circuit to the control terminal of the first switching circuit, thereby enabling the first output power circuit.

Abstract: A power unit for an electric vehicle includes: a first power source connected between a first node and a second node; a first switch connected between the second node and a third node; a second power source connected between the third node and a fourth node; a second switch connected between the first node and the third node; and a DC-DC converter, wherein the DC-DC converter adjusts an electric potential of the first node by changing an electric potential of the second node by making the first node connectable to the third node, or, by making the second node connectable to the third node; an output electric power obtained from between the first node and the fourth node is supplied to an electric motor; and the first power source or the second power source is a fuel cell stack and an another is a secondary battery.

Abstract: An envelope tracking power supply circuit is a power supply circuit for generating an output voltage according to the envelope of a high frequency signal and includes a voltage follower circuit for receiving an envelope signal and outputting a voltage according to the envelope signal; two parallel resistors connected in parallel between the output of the voltage follower circuit and an output terminal; hysteresis comparators for detecting respective voltage drops in the parallel resistors and generating voltages according to the voltage drops; and switching converters for performing switching according to the respective voltages outputted from the hysteresis comparators and outputting a voltage to the output terminal.

Abstract: A temperature compensation circuit is used in a peak current control multi-phased DC/DC converter. Each phase has a duty cycle needed to generate a regulated output voltage of the converter. The temperature for each phase in the converter is sensed to generate corresponding first signals for all the phases. The first signals are averaged to generate a second signal corresponding to the average temperature of all the phases. For each phase, a third signal is generated corresponding to the difference between the first signal and the second signal. The third signal is then used to adjust the duty cycle of each phase to control the temperature of each phase to be substantially equal to the average temperature. In the steady state, the output voltage of the converter will be the desired voltage and the temperatures of the phases will be balanced.

Abstract: An embodiment of a power supply includes an input node operable to receive an input voltage, an output node operable to provide a regulated output voltage, an odd number of magnetically coupled phase paths each coupled between the input and output nodes, and a first magnetically uncoupled phase path coupled between the input and output nodes. Such a power supply may improve its efficiency by activating different combinations of the coupled and uncoupled phase paths depending on the load conditions. For example, the power supply may activate only an uncoupled phase path during light-load conditions, may activate only coupled phase paths during moderate-load conditions, and may activate both coupled and uncoupled phase paths during heavy-load conditions and during a step-up load transient.

Abstract: In a converter of a motor drive control device, one of a first switching element and a second switching element is selected in accordance with a current command value of a current flowing through a reactor. The converter is then controlled so that a drive command for the selected switching element is generated. In this way, the efficiency of the converter is improved while a voltage step-up or step-down operation is performed by the converter.

Abstract: A power unit for an electric vehicle includes: a first power source connected between a first node and a second node; a first switch connected between the second node and a third node; a second power source connected between the third node and a fourth node; a second switch connected between the first node and the third node; and a DC-DC converter connected to the second node, wherein the DC-DC converter changes an electric potential of the second node by making the second node connectable to the fourth node or the third node, and an output electric power obtained from between the first node and the fourth node is supplied to an electric motor.

Abstract: Circuits, methods, and apparatus that reduce the power required to drive transistors in switching power supply regulators under various load conditions. One example provides a power supply regulator having multiple parallel transistors in order to reduce series on resistance. When the regulator is lightly loaded, a reduced number of devices are driven by the regulator. That is, one or more devices are not driven, rather their gates are held at a voltage such that the devices remain in the off or non-conductive state. When the regulator is more heavily loaded, more or all of the devices are driven.

Abstract: A multiphase power supply device and a current adjusting method thereof are provided in the application. The multiphase power supply device outputs power sources and currents with different phases to a microprocessor, and a detection module detects present temperature values of each phase power source to adjust currents of each phase power source to achieve thermal balance. The multiphase power supply device further can automatically measure the power efficiency and display results including the detected temperature values of each phase power source and the power efficiency on a screen, and thus the user can know the operation efficiency of the power supply device conveniently.

Abstract: An embodiment of a power supply includes an input node that receives an input voltage, an output node on which a regulated output voltage is provided, an odd number of magnetically coupled phase paths each coupled between the input and output nodes, and a first magnetically uncoupled phase path coupled between the input and output nodes. Such a power supply can improve its efficiency by activating different combinations of the coupled and uncoupled phase paths depending on the load conditions. For example, the power supply may activate only an uncoupled phase path during light-load conditions, may activate only coupled phase paths during moderate-load conditions, and may activate both coupled and uncoupled phase paths during heavy-load conditions and during a step-up load transient.

Abstract: A device includes a controller that receives current values generated by at least four parallel load commutated inverters (LCIs). The controller includes a source firing generator that generates independent source firing commands for each of the at least four parallel LCIs based on the received current values and transmits each of the independent source firing commands to a respective one of the at least four parallel LCIs, wherein the source firing commands are configured to set input phase angle values of the four parallel LCIs.

Abstract: The power supply comprises a bridge rectifier connected to an AC source; a boost converter series-connected to the bridge rectifier comprising an inductance coil; a filter capacitor series-connected to the boost converter; a DC/DC converter connected to a load; a hold-up-time enhancer connected to and positioned between the filter capacitor and the DC/DC converter; and a virtual by-pass system parallel-connected to the hold-up-time enhancer comprising an induction coil inductively coupled to the inductance coil of the boost converter. As such, voltage is induced on the induction coil by the inductance coil in the boost converter and the virtual by-pass system parallel-connected to the hold-up-time enhancer is thereby turned on and off.

Abstract: A method of operating a regulator controller IC for performing intermittent diode braking for controlling a multiple phase voltage regulator. The method includes receiving at least one signal for detecting repetitive load transients, determining a rate of the repetitive load transients, generating diode braking control signals, each for applying diode braking to a corresponding one of multiple phases for at least one load transient when the repetitive load transients are below a first rate, and controlling the diode braking control signals to drop application of diode braking of at least one phase for at least one load transient when the repetitive load transients are at least the first rate. The method may include rotating the application of diode braking among the phases during successive applications of diode braking. The method may include dropping an increased number of phases for diode braking as the rate of repetitive load transients is increased.

Abstract: An electrical circuit for manipulating at least one of a voltage and a current on a bus wire comprises a first switch having a first gate, a first source, and a first potential reduction unit. The first potential reduction unit is suitable for lowering a potential difference between the first gate and the first source of the first switch, wherein the lowering of the potential difference is caused by a shutting-off of a first control voltage.

Abstract: A power supply circuit can be configured to include a first circuit and a second circuit. Each circuit can be substantially identical to each other but provide different functionality depending on how they are configured. For example, each of the first circuit and second circuit can be chips having substantially the same pin layout and internal circuitry. However, the functionality provided by the circuits varies depending on whether a respective circuit is configured as a master or slave. The first circuit is configured as the master and generates multiple phase control signals. The first circuit uses a portion of the multiple phase control signals to control a first set of phases. The first circuit transmits a second portion of the multiple phase control signals to the second circuit configured as a slave. The second circuit is configured to receive and use the second portion of control signals to control a second set of phases.

Abstract: A current source circuit with temperature compensation includes a power supply terminal, a reference current source unit connected to the power supply terminal, a feedback control unit connected to the power supply terminal and the reference current source unit, a current source generating unit connected to the feedback control unit and a ground terminal connected to the current source generating unit. The reference current source unit is a current source connected to the power supply terminal. The feedback control unit includes a first switching element, connected to the current source, and an inverting amplifier, connected between the current source and the first switching element. The current source generating unit includes a second switching element, connected to the first switching element, the current source and the inverting amplifier, and a first resistor, connected to the first and the second switching elements and the ground terminal.

Abstract: A control system for regulating an output voltage of a DC-DC converter having N phases, where N is an integer greater than one, includes a pulse generator and a frequency divider. The pulse generator generates a stream of fixed on-time pulses, each pulse triggered in response to current through an alternating one of the N phases falling to a threshold value. The frequency divider divides the stream of fixed on-time pulses into N phase signals for controlling the N phases. A method for regulating an output voltage of a DC-DC converter having N phases, includes the following steps: (1) generating a stream of fixed on-time pulses, each pulse triggered in response to current through an alternating one of the N phases falling to a threshold value, and (2) dividing the stream of fixed on-time pulses into N phase signals for controlling the N phases.

Abstract: A multiphase power regulator includes a multiphase pulse width modulator, an output stage and an active transient response circuit. The output stage includes a high side transistor, a low side transistor and an inductor. The output stage is configured to supply power to a load responsive to signals generated by the multiphase pulse width modulator. The active transient response circuit is coupled between the output stage and the multiphase pulse width modulator and configured to detect the voltage level at the output stage and provide a signal to the multiphase pulse width modulator that is a function of the amplitude of the deviation of the detected voltage level from a target voltage.

Abstract: This invention offers a power supply circuit that is capable of improving a power factor as well as reducing a ripple current of an input/output of the power supply circuit due to switching of a switching device. The power supply circuit is provided with a first power supply circuit including first and second switching devices, a second power supply circuit including third and fourth switching devices and a switching control circuit. The switching control circuit controls the switching devices so that the first switching device and the third switching device are turned on and off at timings different from each other when an alternating current voltage from an alternating current power supply is positive, and the second switching device and the fourth switching device are turned on and off at timings different from each other when the alternating current voltage is negative.

Abstract: A method for operating an electric power generating system (EPGS) includes, in one aspect, detecting current limiting conditions in the SSPC, wherein the SSPC includes a main solid state switch in series with an output filter that includes a first solid state switch, and wherein a decoupling filter comprises a second solid state switch. Another aspect includes, based on the detection of the current limiting conditions in the SSPC, opening the first solid state switch and the second solid state switch; detecting an absence of current limiting conditions in the SSPC; and, based on the detection of the absence of current limiting conditions in the SSPC, closing the first solid state switch and the second solid state switch, and powering a direct current (DC) load by a generator of the EPGS via the output filter and the SSPC.

Abstract: A multiphase controller for a DC-to-DC power supply includes logic to estimate parameters for multiple phases that provide a combined output at a load. The estimated parameters include a current estimate and an effective resistance estimates for each phase so that a power estimate for each phase can be produced. The logic adjusts the operation of the phases using the power estimate for each phase.

Abstract: A method of controlling at least one voltage converter having a plurality of cells in series, comprising an AC part and a DC part, characterized in that the AC input voltage (Vei) of each cell is determined directly by the use of a high speed current control loop relating to the AC part and a lower speed voltage control loop relating to the cells, the method including choosing the following voltage control law: ? i = C i 2 ? ( 2 R pi ? C i ? Z i + ? ? t ? Z i ? ? _ ? ? ref - K 1 ? Zi - K 2 ? Zi ? sign ? ( E Zi ) ) where: K1zi and K2zi are positive adjustment gains; Ci is the continuous capacitance of the capacitor Ci of each cell; Rpi is the losses associated with each cell; Zi—ref is the reference value of Zi=(UDCi)2, UDCi; being the direct voltage across the capacitor Ci; and EZi is such that EZi=Zi?Zi—ref.

Abstract: For a multiphase interleaved voltage regulator, an offset cancellation circuit is applied for each phase separately. The current loop gain of each phase is thus increased to mitigate the beat-frequency oscillation in phase currents when the beat frequency is below the bandwidth of the low-pass filter in the offset cancellation circuit, without introducing additional instability issue that is the drawback of increasing current-sensing gain.

Abstract: A control method is provided for controlling an asymmetric DC-DC converter including first and second power switches that are driven respectively by first and second control signals, and a voltage-converting circuit that is operatively associated with the first and second power switches for generating an output signal. The voltage-converting circuit includes a primary coil unit and a secondary coil unit operatively associated therewith for voltage conversion, and including first and second coils that have a turn ratio not equal to one. The control method includes: sampling the output signal to obtain a sample signal corresponding thereto; and generating the first and second control signals, which correspond respectively to first and second duty cycles having a sum of one, based on a comparison between the sample signal and a reference signal such that the first and second power switches are driven in an alternating manner.

Abstract: In a power supply with n interlaced conversion cells, a control device activates m paths out of n paths, 1?m?n, as a function of the power or of the current handled by the power supply. The cell may have a boost, buck, buck/boost, Cuk, or SEPIC topology.

Abstract: There is provided a multiphase switching power supply circuit in which an input terminal receives an input voltage, an output terminal outputs an output voltage, first to an Nth power stages each include an inductor having one end connected to the output terminal; a high-side switch that connects another end of the inductor to the input terminal; and a low-side switch that connects the other end of the inductor to a reference voltage, a switch signal controller supplies first to an Nth control signals to the first to Nth power stages, the first to Nth control signals complementarily turning on and off their corresponding high-side switches and low-side switches at a frequency fs, and a switch signal controller determines phases of the first to Nth control signals according to a ration between inductance values of the inductors included in the first to Nth power stages.

Abstract: A power supply conversion circuit includes a PWM chip and many sub-circuits. Each sub-circuit includes an inductor, a first capacitor connected to ground, a first resistor connected in series with the first capacitor to form a branch parallel to the inductor, a differential pair having a first differential signal trace and a second differential signal trace, a second resistor, and a second capacitor. The first trace is connected between the connection of the first resistor and the first capacitor and the PWM chip. The second resistor is connected between the connection of the first resistor and the inductor and the second capacitor. The second trace is connected between the connection of the second resistor and the second capacitor and the PWM chip. The ratios of the capacitances of each two second capacitors are the same as that of the lengths of the traces of each two corresponding differential pairs.

Abstract: A direct current (DC) converting circuit includes a DC input end, for receiving a DC input voltage; a DC output end, for providing a predetermined DC voltage; a switch, coupled between the DC input end and the DC output end, for providing a direct path; a DC-DC step-down unit, coupled between the DC input end and the DC output end, for providing a step-down voltage path; and a control unit, coupled to the switch and the DC-DC step-down unit, for detecting the DC input voltage and selecting either the direct path or the step-down voltage path to provide the predetermined DC voltage at the DC output end. The DC power converting circuit can be applied in power supply circuits of multi-media players or TV setup boxes to convert DC input voltage including 5V, 9V or 12V DC voltages to a predetermined DC voltage.

Abstract: A multiphase DC-DC converting circuit for providing power to a load is disclosed, having power stage circuits, channel current converting circuits, current detecting circuits, a transconductance amplifier circuit, a comparator circuit, and a channel current balance circuit. The current detecting circuits detect current signals of current channels, and the transconductance amplifier circuit and the comparator circuit are coupled with the current detecting circuits to receive the voltage difference across a resistor, and to generate a total current detecting signal provided to the load. The channel current converting circuit is coupled with the current detecting circuits to generate channel current detecting signals. The channel current balance circuit is coupled with the comparator circuit, the transconductance amplifier circuit and the channel current converting circuit to balance the current signals of the current channels.

Abstract: The present invention discloses a buck switching regulator including a power stage, a driver circuit and a bootstrap capacitor. The power stage includes an upper-gate switch, a first lower-gate switch and a second lower-gate switch. The first upper-gate switch is electrically connected between an input terminal and a switching node. The first lower-gate switch is connected in parallel with the second lower-gate switch, both of which are electrically connected between the switching node and a first node. The driver circuit controls the operation of the upper-gate switch and the first lower-gate switch. The bootstrap capacitor is electrically connected between a boot node and the switching node, wherein the boot node is electrically connected to a supply voltage. When a voltage across the bootstrap capacitor is smaller than a reference voltage, the second lower-gate switch is turned on to charge the bootstrap capacitor from the supply voltage.

Abstract: A power control system includes a power regulator having a plurality of power PMOS transistors connected to a power source in parallel and configured to supply current and voltage controlled according to an input lamp voltage, a current sensing unit connected to the power source and configured to sense currents flowing through a plurality of target PMOS transistors located at predetermined positions among the PMOS transistors, a current mirror unit connected to a first regulated voltage terminal and configured to generate a plurality of currents equal to the sensed currents, a comparator unit configured to total the generated currents to convert the totaled currents into a voltage, and to generate a voltage difference between the voltage and a predetermined reference voltage, and a current bias circuit unit connected to a second regulated voltage terminal and configured to control a bias current according to the generated voltage difference.

Abstract: In a circuit apparatus for transformerless conversion of an electric direct voltage of a two-pole direct voltage source (1) connected to ground having a first voltage pole (+) and a second voltage pole (?) into an alternating voltage, hazardous capacitive leakage currents are avoided by connecting the direct voltage source (1) to ground and the DC-AC converter (400) is operated at a controlled intermediate circuit voltage, a DC-DC converter stage (300) being connected between the direct voltage source (1) and the DC-AC converter (400), said DC-DC converter stage providing at its output a +/? voltage that is symmetrical with respect to the grounding point, two series-connected capacitors (41, 42) having the same polarity and being connected to ground at their connecting point (V) and controlled are charged by two buck-boost choppers (100, 200) connected one behind the other.