Abstract: A startup circuit for use in a DC-DC converter having an input voltage terminal and an output voltage terminal, with the output voltage terminal connected to an output capacitor and with said converter including a pass transistor for transferring charge from the input terminal to the output terminal. The startup circuit includes a control circuit configured to cause the pass transistor to conduct an output current during start up when the output terminal voltage is approaching a final regulated voltage, with the output current being comprised of first and second current components, with the first current component being proportional to the output voltage and the second current component being proportional to the input voltage, with the two components being combined so as to resist changes in the power dissipation in the pass transistor during startup.

Abstract: Provided is a constant current circuit capable of low current consumption operation, which is prevented from repeating a start-up state and a zero steady state and entering an oscillating state when power is activated. When power is activated, until a node (A) reaches a start-up state, an excitation current is continued to be supplied to a node (B), to thereby reliably start up the constant current circuit in a short period of time without repeating the start-up state and the zero steady state.

Abstract: A start-up circuit to discharge EMI filter is developed for power saving. It includes a detection circuit detecting a power source for generating a sample signal. A sample circuit is coupled to the detection circuit for generating a reset signal in response to the sample signal. The reset signal is utilized for discharging a stored voltage of the EMI filter.

Abstract: A circuit arrangement includes a switching element that switches a load current, a current-limiting element connected in series to the switching element, a bistable first relay connected in parallel to the switching element and the current-limiting element, and a control circuit that switches the power-supply unit from a first operating state to a second operating state in which a load current for generating a DC voltage flows from the power grid to the power-supply unit, such that the control circuit turns on the switching element for a first time period during switching of the power-supply unit from the first to the second operating state, to turn the bistable relay on during the first time period, and to turn the switching element off at the end of the first time period.

Abstract: A start-up circuit to discharge EMI filter is developed for power saving. It includes a detection circuit detecting a power source for generating a sample signal. A sample circuit is coupled to the detection circuit for generating a reset signal in response to the sample signal. The reset signal is utilized for discharging a stored voltage of the EMI filter.

Abstract: An isolated switched mode power supply (SMPS) is disclosed. The SMPS comprises a switching controller to generate start-up and operational switching control signals. The SMPS further includes a transformer, having a primary winding, and a full-bridge drive circuit to drive the primary winding. The full-bridge drive circuit comprises a first switching element, a boot-strap dnving circuit, and a second switching element. The switching controller is further used to start up isolated SMPS by determining a duty cycle for operational control signals and generating the start-up switching control signals.

Abstract: A method and a control device control a switching device for providing a resonant circuit with a switching voltage for generating a resonant current in order to provide a required output power at an output of a resonant power converter.

Abstract: Soft start circuits for a switching power converter include an amplifier configured to operate from a common bias node and amplify a difference between a positive input and a negative input to generate an amplifier output. A soft start bias circuit supplies a soft start bias current during a soft start process for the switching power converter. An operational bias circuit supplies an operational bias current after the soft start process. In some embodiments, a capacitor is operably coupled to the amplifier output and is configured to provide a frequency compensation for the switching power converter and a charging ramp for the soft start process. In some embodiments, the soft start circuit is configured such that the soft start bias current is at least an order of magnitude smaller than the operational bias current and limits a current that the amplifier can during the soft start process.

Abstract: A start-up circuit includes a switching-device control circuit arranged to receive an input voltage and to provide a switching-device control signal, a switching device arranged to be controlled by the switching-device control signal and to provide a start-up signal, a power-converter control circuit arranged to receive the start-up signal and to provide a power-converter control signal, and a power converter arranged to receive the power-converter control signal and to provide an auxiliary output signal. The switching control circuit is arranged to receive the auxiliary output signal such that, when the auxiliary output signal reaches a predetermined level, the switching-device control circuit stops providing the switching-device control signal.

Abstract: Provided is a DC-DC converter including a soft start circuit capable of prolonging a soft start time without increasing a capacitance used in the soft start circuit. A soft start is implemented by gradually increasing a limiting level of an inductor current or a reference voltage. The soft start time is adjusted by varying a frequency of CLOCK signals supplied to switch circuits. The soft start time may be prolonged without increasing a chip size because the capacitance does not need to be increased to prolong the soft start time.

Abstract: A power conversion system with zero-voltage start-up mechanism and a zero-voltage start-up device are disclosed. The system includes a power conversion circuit, a power factor correction unit, a storage capacitor, a storage switching unit, and a zero-voltage detection module. The storage switching unit is serially connected with the storage capacitor, and particularly controlled by the zero-voltage detection module. The zero-voltage detection module detects a timing as an input voltage is at low level, and then outputs a control signal to turn on the storage switching unit. Therefore, the present invention assures that the power conversion system is turned on when the input voltage is at the low level, in order to suppress the system from a surge current.

Abstract: A startup circuit for starting up a self-supplied voltage regulator which initiates startup by applying a voltage from a voltage supply to the startup circuit thus causing a voltage at an output node to rise. This rise will start the operation of the differential amplifier of the voltage regulator. When the voltage at the output node has reached the desired final output voltage, the startup circuit disconnects from the voltage regulator. The criterion for switching off the startup circuit is determined by a comparator which compares the output current capability of the voltage regulator with its output current plus the startup current. Inputs to the differential amplifier, such as the reference voltage, derive their power from the output node.

Abstract: Upon detecting an external signal which instructs to stop discharge, an input voltage equal to or less than a set value for the prevention of overdischarge, or an output voltage equal to or more than a set value for the prevention of output of an overvoltage, a control unit (12) stops discharge to a load (40) by opening a switching element (4b) of a step-down unit (11b). Upon detecting that an external signal is reset or an input voltage equal to or more than a set value larger than the set value for the prevention of overdischarge, the control unit (12) resumes discharge to the load (40) by setting the switching element (4b) in a switching operation state or short-circuiting it.

Abstract: System and method for providing stable control for power systems. According to an embodiment, the present invention provides an apparatus for providing one or more control signals for a power system. The apparatus includes an input terminal for receiving an electrical energy, which can be characterized by a first input voltage. The apparatus includes a control component that is configured to generate a first control signal based on at least information associated with the first input voltage. The apparatus additionally includes an output terminal for sending the first control signal. Moreover, the apparatus includes a timing component that is coupled to the control component. The control component is configured to process at least information associated with a first value of the first input voltage at a first time and a first reference voltage and to generate a second control signal.

Abstract: A self-contained power source to charge a battery and/or power a load is provided. The power source does not utilize a connection to an external power supply, such as AC mains and/or an AC to DC converter. In one embodiment, the self-contained power source includes an ultra low voltage power generator, such as 0.3V of a single solar cell, or even lower to slightly above the GND potential, that provides a voltage to a rechargeable battery, a load or both. A voltage converter with boost topology is used to supply a voltage comparable to the voltage of the rechargeable battery. A first push circuit containing a zero threshold voltage switch, a MUX circuit and a one-pulse-control block is utilized to ensure initial and continued operation of the voltage converter.

Abstract: A soft-stop overvoltage protection circuit, into which a soft-stop overvoltage detection voltage proportional to a direct current output voltage is input, reduces the output of a multiplier in accordance with the soft-stop overvoltage detection voltage when the soft-stop overvoltage detection voltage exceeds a first threshold value. An overvoltage protection circuit, a second threshold value higher than the first threshold value being set, compulsorily turns off a switching element by outputting an overvoltage detection signal when the soft-stop overvoltage detection voltage exceeds the second threshold value. The soft-stop overvoltage protection circuit compulsorily increases the output of a voltage error amplifier circuit on the output voltage decreasing. When the output of the voltage error amplifier circuit increases suddenly, and the output voltage rises excessively, the soft-stop overvoltage protection circuit decreases the output of the multiplier, thus curbing the rise of the output voltage.

Abstract: A switch-mode controller, buck converter or DC to DC step-down regulated voltage converter that senses an initial pre-bias voltage at initialization and adjust a duty cycle of the switching frequency to help minimize an output voltage transient at initialization or power-on reset.

Abstract: A start circuit including a load unit, a first switch, a second switch and a reset control circuit is provided. The load unit receives a power voltage. The first switch is electrically connected between a first end of the load unit and a ground, and receives a node voltage from a reference circuit. The second switch has a first end electrically connected to the reference circuit, a second end electrically connected to the ground, and a control end electrically connected to the second end of the load unit. The second switch determines whether to provide a start voltage to the reference circuit according to a conducting state thereof. The reset control circuit provides a discharge path between a control end of the first switch and the ground, and conducts the discharge path according to the power voltage during a period when the power voltage is smaller than a threshold voltage.

Abstract: Electrical supply apparatus comprising a start-up circuit element coupled to an output element for ensuring reliable start-up when first connected to a source of power. The start-up circuit element comprises first and second branches with current mirror coupling therebetween. The first branch comprises first and second transistors of opposite polarities for connection in series between the source of power and ground and a leakage path to ground in parallel with the second transistor for start-up current for the first transistor of the first branch in response to application of voltage from the source of power. The current mirror coupling between the first and second branches responds to start-up of the first transistor of the first branch to start up a first transistor of the second branch and provide start-up current to the output element.

Abstract: A start circuit adapted to start a reference circuit including a plurality of bias nodes is provided. The start circuit includes a current source, a current mirror, a load device, and a control device. The current source determines whether or not to generate an internal current according to a plurality of bias voltages on a part of the bias nodes. The current mirror duplicates the internal current to produce a mirrored current. The load device adjusts a control voltage according to the mirrored current. The control device determines whether or not to generate a start voltage according to the control voltage, and transmits the start voltage to one of the part of the bias nodes, so as to break the reference circuit away from a zero-current state.

Abstract: A power management (PM) system architecture for a controlled SoC detects availability of power supply for signal-driving at a given node inside a chip, and uses a timer, a discharge mechanism with trigger for starting/stopping a discharge process, and a comparator for monitoring a measured voltage of an intended node during the discharge process. Enabling the discharge mechanism for a known time period helps detection. Power supply can be internally generated in the chip or from a source on board. The architecture detects if the node is driven or floating, an undriven floating node causing a dip in the measured voltage. The measured voltage does not have a dip when the node is driven. The architecture is also configured so that when there is a required on-board external power supply, an internal power supply is disabled to avoid a race-condition. The architecture obviates a dedicated IO pin for mode-indication.

Abstract: The present abstract discloses a CMOS bandgap reference source circuit, comprising a startup circuit, a power-off control circuit, a reference voltage generating circuit and an operational amplifier. The positive and a negative input terminal of the operational amplifier both consist of two same field effect transistors and both are provided with an input controlled switch; by doing so, two field effect transistors in the positive terminal and two field effect transistors in the negative terminal work alternately between their strong inversion and cut-off region so as to drastically reduce the noises of the reference circuit, which results originally from the flicker noises of two input transistors of the operational amplifier.

Abstract: A power supply control device includes a boost type power supply controller boosting an input voltage, a step down power supply controller reducing an output of the boost type power supply controller to output an output voltage, a first control loop including the boost type power supply controller, and a second control loop including the step down power supply controller, wherein the output voltage is controlled by the second control loop during a predetermined period beginning after the power supply control device enters a power-on state, and wherein the output voltage is controlled by the first control loop after the predetermined period passes.

Abstract: In accordance with a bandgap circuit and a method of starting the bandgap circuit, a start signal is continuously supplied to a differential amplifier circuit to start up the differential amplifier circuit that controls a bandgap core circuit until the differential amplifier circuit has started up, and then the supply of the start signal to the differential amplifier circuit is discontinued after the differential amplifier circuit has started up.

Abstract: A DC/DC converter including an inductor and a capacitor is started by connecting an input voltage to the inductor and shunting a current around the inductor so as to pre-charge the capacitor to a predetermined voltage.

Abstract: A reference voltage generation circuit is disclosed. The reference voltage generation circuit includes an operational amplifier configured to output a constant voltage in accordance with reference voltages input to first and second terminals of the operational amplifier, and a start-up circuit configured to initiate operation of the operational amplifier when the start-up circuit switches from an idle mode to an active mode, including a first transistor having a gate connected to an output of the operational amplifier, a source connected to a supply voltage, and a drain connected to a resistor, configured to supply a reference current to the resistor in accordance with the operational amplifier output, thereby generating the reference voltage.

Abstract: A disclosed constant voltage circuit is configured to become active or inactive and convert an input voltage applied to an input terminal into a predetermined constant voltage for output from an output terminal. The circuit includes an output transistor for supplying, from the input terminal to the output terminal, an output current, an error amplifier circuit unit for controlling operations of the output transistor to make a first proportional voltage, which is proportional to the output voltage from the output terminal, equal to a predetermined reference voltage, a ramp voltage generating circuit unit for generating and outputting a ramp voltage whose voltage level increases at a predetermined speed from start-up, and an amplifier circuit unit for amplifying the voltage difference between the ramp voltage and a second proportional voltage, which is proportional to the output voltage, and outputting the amplified voltage difference to a control electrode of the output transistor.

Abstract: The present invention relates to a switch control device and a converter including the same. According to an exemplary embodiment of the present invention, the switch control device includes a PWM controller for forcing a power switch to turn on when the power switch is turned off during a predetermined period, a current sensor for determining whether a current flows through the power switch, and a conditional counter for determining that an input voltage is input to a power transmission element by using a sense result of the current sensor and a number of times that the PWM controller turns on the power switch by force.

Abstract: Methods and apparatus for power supply load dump compensation according to various aspects of the present invention may operate in conjunction with a power stage system, such as a power stage system comprising a bootstrapped driver circuit and a power stage responsive to the driver circuit. The power stage system may further include a load dump compensation circuit connected to the driver circuit, wherein the load dump compensation circuit is configured to remove a bias current generated by the bootstrapped driver circuit. Various aspects of the present invention may be implemented in conjunction with any appropriate power supply, such as a switching regulator, for example a buck converter.

Abstract: A soft-start circuit to generate and output a soft-start voltage having a specified gradient. The soft-start circuit includes a slope voltage generator circuit to generate and output multiple slope voltages having different specified gradients, including a steepest slope voltage whose gradient is steepest among the gradients of the multiple slope voltages and a mildest slope voltage whose gradient is mildest thereamong, at least one voltage conversion circuit to receive the slope voltages and output a voltage whose gradient is milder than the gradient of the steepest slope voltage, and a selection circuit to receive at least one specified reference voltage and the voltage generated by the voltage conversion circuit, compare the voltage by the voltage conversion circuit with the specified reference voltage, and output either the voltage or the specified reference voltage as the soft-start voltage in accordance with a comparison result generated by the selection circuit.

Abstract: A power supply device has an error amplifier producing an error voltage by amplifying a difference between a feedback voltage according to an output voltage and a predetermined reference voltage, an output portion producing a desired output voltage from an input voltage in such a way that the error voltage is reduced, and a clamping portion setting, during a predetermined period after startup of the power supply device, an upper limit of the error voltage to a value that is lower than a value obtained at normal times, such that the lower the input voltage the higher the upper limit, the higher the input voltage the lower the upper limit.

Abstract: Disclosed are a switch controller, a switch control method, a converter using the same, and a driving method thereof. A first voltage is generated by using a voltage that is input to an input terminal, and a soft start signal is generated by using the first voltage during a soft start duration. A switching operation is controlled by using the soft start signal during the soft start duration.

Abstract: A PSE configured to determine the end of the start up phase at the PD responsive to a condition of the voltage at the PSE output. In one particular embodiment, the startup phase end is determined responsive to a PSE output voltage within a predetermined range of the PSE input voltage. In another particular embodiment, the startup phase end is determined responsive to the voltage drop associated with the PSE current limiter being lower than a predetermined maximum. In yet another particular embodiment, the startup phase end is determined responsive to the absolute value of the rate of change of the PSE output voltage being lower than a predetermined value. In yet another particular embodiment, the startup phase end is determined responsive to the absolute value of the rate of change of the voltage drop associated with the PSE current limiter being lower than a predetermined value.

Abstract: A bandgap circuit, a starter circuit, and a monitoring circuit for a bandgap circuit including a bandgap reference circuit having a first branch and a second branch, the first branch having a first node, the second branch having a second node, such that a potential at the first node is equal to a potential at the second node in an equilibrium of the bandgap reference circuit. The bandgap reference circuit further having a feedback node for a feedback signal and a feedback circuit coupled to the first and second nodes and adapted to provide a feedback signal to the feedback node based upon a comparison of the potentials at the first and second nodes.

Abstract: A start up circuit (4-1) for a boost circuit (10) includes an adjustable-duty-cycle oscillator (1-2) that turns on a switch transistor (MSW) connected to an inductor (L) receiving an input voltage (VIN). If a voltage (V9) of a junction between the transistor and the inductor exceeds a predetermined value corresponding to a maximum inductor current (IL), an amplifier (A1) immediately terminates a first phase of an oscillator cycle, which turns off the transistor. Built-up inductor current is steered into a load. Duty-cycle-adjustment circuitry (R1,R2,C1) causes the oscillator to complete a normal second phase of the cycle before a new cycle begins.

Abstract: A device for precharging a voltage converter is provided with a precharging unit, capable of assuming a closed state, as well as with a control unit for the precharging unit, the precharging unit being capable of operating according to a precharging state limiting the value of the precharging current passing through it, the control unit being capable of commanding the operation of the precharging unit according to the precharging state and, once the precharging has been completed, of commanding the precharging unit to change over from the precharging state to the closed state. The assembly has a chopping voltage converter and such a device disposed at the input of the converter. The aircraft is equipped with such a device or with such an assembly.

Abstract: The invention relates to a DC to DC converter comprising a DC to DC converter unit (DCW), a first field effect transistor (FET1) for the voltage conversion, a bipolar transistor (BP1) as a starting aid, and a second field effect transistor (FET2) for switching-off the bipolar transistor (BP1). Said bipolar transistor (BP1) is mounted in parallel with the first field effect transistor (FET1), and the second field effect transistor (FET2) is mounted upstream of the bipolar transistor (BP1).

Abstract: A low dropout regulator includes an error amplifier, an N-type depletion MOSFET, a first switch, a second switch, a low-pass filter resistor, and a low-pass filter capacitor. By switching on both the first switch and the second switch, a voltage level of an output node at a negative input terminal of the error amplifier may be rapidly raised to be close to and lower than a voltage level of an input node at a gate of the N-type depletion MOSFET. Both the first switch and the second switch are then switched off immediately so that the voltage level of the output node is gradually raised to be equal to the voltage level of the input node through the low-pass filter resistor.

Abstract: An over current protection circuit and a power converter using the same. The over current protection circuit includes a soft start cell and an operational amplifier. The soft start cell outputs a soft start signal according to a direct current (DC) level, and the soft start signal increases progressively to the DC level in a soft start interval. The operational amplifier outputs an over current signal to a feedback control circuit according to the soft start signal and an inductance current of a switching converter so that a duty cycle of a driving signal from the feedback control circuit increases progressively in the soft start interval.

Abstract: A power supply circuit arranged in a circuit board to supply a determined voltage to an element is disclosed. The power supply circuit includes two voltage receiving terminals to receive voltage signals, a window comparator, and an electrical switch. The comparator drives the electrical switch to be turned on, therefore a terminal of the electrical switch stably output the determined voltage to the element.

Abstract: System and method for providing stable control for power systems. According to an embodiment, the present invention provides an apparatus for providing one or more control signals for a power system. The apparatus includes an input terminal for receiving an electrical energy, which can be characterized by a first input voltage. The apparatus includes a control component that is configured to generate a first control signal based on at least information associated with the first input voltage. The apparatus additionally includes an output terminal for sending the first control signal. Moreover, the apparatus includes a timing component that is coupled to the control component. The control component is configured to process at least information associated with a first value of the first input voltage at a first time and a first reference voltage and to generate a second control signal.

Abstract: A reference generator circuit generates a reference signal for use by a regulator in generating operational power for circuits and devices. A start-up circuit includes a self-biased voltage reference and a differential amplifier configured to generate a start-up signal to induce current flow in response to a voltage independent reference signal during a start-up phase of the circuit and cease inducing the current flow following the start-up phase of the circuit. The reference signal is generated by receiving a supply voltage and inducing current flow into a node of a bandgap reference circuit during a start-up phase of the bandgap reference circuit and ceasing inducing the current flow following the start-up phase of the bandgap reference circuit.

Abstract: A first resistance element is coupled between a first rectifying element and an output node at which a reference voltage is generated. Second and third resistance elements are coupled in series between a second rectifying element and the output node. A differential amplifier outputs a control voltage corresponding to a difference between a first voltage generated at a connection point of the first rectifying element and the first resistance element and a second voltage generated at a connection point of the second resistance element and the third resistance element. A control circuit supplies a control current corresponding to the control voltage from the differential amplifier. A start-up circuit causes, by supplying a start-up current to the output node in response to supply of a power supply voltage, transition from a first stable state to a second stable state.

Abstract: Example embodiments relate to an internal power supply voltage generating device. The internal power supply voltage generating device may include a start-up voltage generating part, a reference voltage generating part, and/or an internal power supply voltage generating part. The start-up voltage generating part may be configured to generate a start-up voltage using an external power supply voltage. The reference voltage generating part may be configured to generate a reference voltage using the start-up voltage. The internal power supply voltage generating part may be configured to generate an internal power supply voltage using the reference voltage and the external power supply voltage. The start-up voltage generating part may be turned off by the reference voltage generated by the reference voltage generating part. Example embodiments also relate to a method of generating an internal power supply voltage.

Abstract: A method involves detecting an inrush current that flows out of a USB port of a first electronic device when a central processing unit (CPU) of the first electronic device is not being powered. The inrush current is detected by a novel inrush current detect circuit when a second electronic device is connected to the USB port. In one example, the first electronic device is a laptop computer having a battery and a USB DC-to-DC converter. The inrush current detect circuit enables the USB DC-to-DC converter such that the USB DC-to-DC converter receives power from the battery and supplies a regulated voltage to the second electronic device through the USB port while the CPU remains unpowered (not drawing power from the battery).

Abstract: An integrated circuit, comprises a wakeup terminal; a supply voltage terminal configured to receive a supply voltage; and a power control circuit. The power control circuit comprises an enable circuit coupled to the wakeup terminal and configured to generate a voltage monitoring enable signal as a response to a wakeup signal received at the wakeup terminal, and a voltage monitoring circuit for generating a supply voltage level indication signal. The voltage monitoring circuit is coupled to the supply voltage terminal and comprises an operation switch controlled by the voltage monitoring enable signal. The voltage monitoring circuit is configured to determine if the supply voltage is above a threshold voltage and set the supply voltage level indication signal accordingly. The integrated circuit further comprises processing circuitry, with the supply voltage level indication signal controlling the switching between a normal operation state and a standby state of the processing circuitry.

Abstract: A power converting device including a pulse width modulation circuit, a switch unit, a power output unit and a voltage start unit is provided. The pulse width modulation circuit increases a start voltage in a soft start mode and is operated under the start voltage to generate a pulse width modulation signal. The switch unit is for receiving an input voltage, and forming a charge path and a discharge path alternately according to the pulse width modulation signal. The power output unit converts the input voltage to a core voltage in accordance with the charge path and the discharge path. The voltage start unit is for detecting the start voltage, and for transmitting a control signal to interrupt the formation of the discharge path when the start voltage is smaller than the core voltage.

Abstract: The invention relates to a switch-mode power converter including a bias circuit. A power converter power transformer includes a magnetic core. The switch-mode power converter power transformer also includes an initial bias primary winding and an initial bias secondary winding, both wound on the magnetic core, wherein the initial bias secondary winding shares at least one magnetic path in common with the initial bias primary winding. A driver is configured to drive the initial bias primary winding with high frequency pulses when enabled by an enable signal. A rectifier and capacitor are configured to provide a voltage to power a control circuit during a power converter start-up. A method provides an initial bias power for a power converter output side referenced controller, powering the output side referenced controller from the initial bias windings.

Abstract: A soft-start circuit is provided. The soft-start circuit comprises: an input stage, a pump stage, a second resistor and a capacitor. The input stage comprises a first resistor to receive an input voltage to provide a reference current at a first node. The pump stage comprises N current branches connected in parallel each comprising a current source connected to the first node and a switch to transfer the current from the current source to the second node while the switch operates in a connecting state. The switches has 2N connecting modes performed one after another to generate an output current with a gradual increment output current at the second node with 2N current levels; and the second resistor and the capacitor are connected in parallel between the second node and the ground potential to generate an output voltage with a gradual increment with 2N voltage levels according to output current.

Abstract: A circuit is provided including an output stage with a pair of transistors. Further provided is a control circuit in communication with the output stage. The control circuit is capable of controlling a duration in which at least one of the transistors is actuated for reducing an in-rush current.