Abstract: Methods and apparatus for detecting a zero inductor current to control switch transitions for a power converter. An example method includes outputting a first voltage and a first current, receiving the first voltage and output a second voltage into an input of a comparator, when the second voltage is above a third voltage, outputting a first output voltage, when the second voltage is below the third voltage, outputting a second output voltage, determining when the first current is zero based the output of the comparator, enabling a set of switches based on when the first current is zero.

Abstract: A discharge switch and a capacitor are connected in series between first and second DC power supply lines. A boost circuit boosts a rectified voltage to charge the capacitor. An inverter receives the rectified voltage as a DC voltage when the discharge switch is not conducting, receives a voltage across the capacitor as the DC voltage when the discharge switch is conducting, converts the DC voltage into an AC voltage, and outputs it to a motor. A switch control unit maintains the discharge switch not conducting over a first time period, and switches the discharge switch between conducting and not conducting in a second time period. A charge and discharge time period setting unit sets the first time period when a rotational speed of the motor is higher than a speed threshold shorter than the first time period when the rotational speed is lower than the speed threshold.

Abstract: A DC-DC converter, which allows a current to pass through an inductor and rectifies the current through the inductor to convert an input direct current voltage supplied from a direct current power unit into a direct current voltage at a different potential and output the direct current voltage, includes a switching control circuit performing peak-current control procedures including turning on the switching element when the converted direct current voltage drops to a predetermined potential and turning off the switching element when the current through the inductor reaches a predetermined value. The converter includes a copied-current generating circuit generating a current proportional to the output current. The switching control circuit turns off the switching element when the circuit detects that the current through the inductor reaches a predetermined value with reference to a combined current of the copied current generated at the copied-current generating circuit and a predetermined reference current.

Abstract: Method and apparatus is disclosed for providing a controlled pre-charging current for capacitive loads coupled to a boost converter. For at least some embodiments, the boost converter may include a high-side field effect transistor (FET) and a low-side FET. The boost converter may provide the pre-charge current by periodically enabling the high-side FET while the low-side FET is maintained in an off state. The high-side FET may be enabled by a square-wave signal. The pre-charge current may be delivered until the output voltage of the boost converter exceeds a reference voltage. After the output voltage exceeds the reference voltage, the boost converter may transition to a normal (switching) operation.

Abstract: A cascaded buck converter for receiving input voltage from an input voltage source and for delivering output voltage to a load. The converter includes a first inductor, a second inductor, a coupled inductor having a first winding connected in series with the first inductor and a second winding connected in series with the second inductor, an intermediate decoupling capacitor for receiving energy from the first inductor and the first winding and for supplying energy to the second inductor and the second winding, and an output decoupling capacitor for smoothening the output voltage at the load.

Abstract: A centralized voltage control apparatus calculates an optimum voltage distribution in a centralized control cycle period and determines, based on the relationship between the optimum voltage distribution and a proper voltage range, voltage upper and lower limit values for which a command is issued to each local voltage control apparatus taking into account voltage upper and lower limit margin amounts at respective points in a voltage control responsible range of the local voltage control apparatus for each local voltage control apparatus. The local voltage control apparatus adjusts, based on the voltage upper and lower limit values commanded from the centralized voltage control apparatus via a communication network, a control amount of a voltage control device every local control cycle shorter than the centralized control cycle period, to maintain the control voltage of the voltage control device between the voltage upper and lower limit values.

Abstract: An electronic system, DC-DC voltage converter, method of operating a buck-boost DC-DC converter, and method for power mode transitioning in a DC-DC voltage converter are disclosed. For example, one method includes receiving a compensated error signal associated with an output voltage of the DC-DC voltage converter, determining a power mode of operation of the DC-DC voltage converter, and if the power mode of operation is a first mode, outputting a first control signal to regulate the output voltage of the DC-DC voltage converter. If the power mode of operation is a second mode, outputting a second control signal to regulate the output voltage of the DC-DC voltage converter, and if the power mode of operation is a third mode, outputting a third control signal to regulate the output voltage of the DC-DC voltage converter.

Abstract: A power management circuit is provided with groups of switches and a single shared inductor and is selectively configured in a first mode to act as a buck regulator and a second mode to act as a buck-boost regulator. There is a two-stage circuit topology, where both charging and regular operation of the device can be optimized. There is a switching charger integrated circuit that can be dedicated to performing a charging function, and there is a DC-DC power management integrated circuit that can be dedicated to regulating the system voltage provided by the battery while the battery is discharging.

Abstract: A voltage regulation circuit can include: a power stage circuit with a single inductor and a plurality of output circuits; each output circuit having an output control switch configured to control a duration of an on time of the output circuit, and an output switch control circuit configured to control the output control switch in accordance with an output voltage sampling signal, a reference current signal that represents an output current of the output circuit, and a clock signal, in order to maintain an output voltage of the output circuit as constant and to decrease interference from load variations of any other of the plurality of output circuits; and where the output control switches are controlled to be on in sequence in each switching period.

Abstract: A DC-to-DC controller, a DC-to-DC power converter and a control method thereof are provided. The controller is coupled to an upper-bridge switch and a lower-bridge switch and includes a time generation unit providing a time signal, a voltage identification (VID) change determining circuit and a time control circuit. The VID change determining circuit provides a determination signal in response to a VID signal. The time control circuit provides a control signal according to the time signal and the determination signal. When the VID signal changes from high to low, the time control circuit turns off the upper-bridge switch for a first preset time according to the determination signal and the time signal, and during the first preset time, the time control circuit controls the lower-bridge switch to be turned on for a second preset time multiple times, and to be turned off for a third preset time multiple times.

Abstract: A power management system comprises a power converter comprising a power stage and configured to detect an abnormal static state of the power stage, to generate a protection signal in response to the detection of the abnormal static state of the power stage, and to stabilize a direct current (DC) power supply voltage in response to an enable signal to generate a DC output voltage, and a main control circuit configured to generate the enable signal for the power converter based on the protection signal received from the power converter.

Abstract: An electrical supply system including a voltage converter including having an input electrically coupled to a supply for receiving a supply signal and an output for supplying an output signal having a output voltage different to a supply voltage of the supply signal. The system includes a diode including a diode input electrically coupled to the voltage converter output, a bus electrically coupled to a diode output and at least one of a load and a store, a voltage sensor for detecting the output voltage, a current sensor for detecting a diode input current and an electronic processing device coupled to the sensors for monitoring the diode input current and the output voltage and detecting a fault in the electrical supply system based on at least the diode input current and output voltage.

Abstract: The exemplified methods and systems support shared output drivers or shared control setting drivers across separate control devices for a redundant system of 1, 2, 3, or more control devices in simplex, dual, triple redundancy, and etc. Digital communication links between the control devices are implemented to facilitate sensing, from other control devices, of operation states (e.g., amount of contribution by the control devices to the shared output) and on-line/health status of other control devices in the redundant network.

Abstract: A voltage regulation system for providing power to a load is provided. The voltage regulation system includes a voltage regulator operable to: set an operating voltage of the load at a first voltage level which corresponds to a first voltage requirement of the load; receive a second voltage requirement of the load which is different than the first voltage requirement; produce a voltage ramp signal which transitions from the first voltage level to a second voltage level which corresponds to the second voltage requirement at a defined ramp rate; and ramp the operating voltage from the first voltage level to the second voltage level based on the voltage ramp signal and at the same ramp rate as the voltage ramp signal, but with a lag between the voltage ramp signal and the ramp in the operating voltage.

Abstract: A control device for a switching voltage regulator having a high-side switch and a low-side switch to supply a switching voltage to a load includes a comparator configured to compare the switching voltage with a reference voltage to provide an enable signal to the low-side switch, and a spike detection circuit configured to receive the switching voltage and output an offset control signal to execute a time shift to the enable signal.

Abstract: In some embodiments, a startup current limiter comprises a first comparator, a second comparator, on time circuitry coupled to an output of the second comparator, and a first logic structure coupled to the output of the second comparator and an output of the on time circuitry. In some embodiments, the startup current limiter further comprises sequencing logic coupled to an output of the first comparator, a latch coupled to an output of the first comparator at a set terminal of the latch and an output of the second comparator at a reset terminal of the latch, off time circuitry coupled to an output terminal of the latch, a second logic structure coupled to the latch and the off time circuitry, and a gate driver coupled to the second logic structure and an output of the sequencing logic.

Abstract: A power supply circuit includes a rectifier module configured to rectify an input voltage and a capacitor including a first terminal coupled to the rectifier module. In addition, the power supply circuit includes first and second transistors. The first transistor couples to a second terminal of the capacitor, and the second transistor couples in series to the first transistor. The power supply circuit also includes a resistor, configured to set an inrush current value, in parallel with the second transistor. When coupled to a power supply, the power supply circuit is configured to turn-on the first transistor such that an inrush current flows, at the inrush current value, through the capacitor, first transistor, and resistor. After a delay time, the power supply circuit is configured to turn-on the second transistor such that the inrush current drops to around zero, thus maintaining a low impedance path during steady-state operation.

Abstract: An embodiment comprises: a voltage generation unit for providing a direct current signal for driving a light emitting unit; a sensing resistor; and a dimming unit which is connected between the light emitting unit and the sensing resistor and controls a current flowing in the sensing resistor and the light emitting unit, wherein the dimming unit adjusts the level of the direct current signal on the basis of a first sensing voltage as a result of sensing the voltage of a first node where a switch is connected to the light emitting unit, and a second sensing voltage as a result of sensing the voltage of a second node where the switch is connected to the sensing resistor.

Abstract: A power supply for use in a solar electric production system, including: a first stage having an input connected to a voltage from a photovoltaic panel and an output providing a first voltage different from the voltage from the photovoltaic panel; and a second stage connected to the output of the first stage, the second stage supplying power at a second voltage to a micro-controller, where the output of the first stage is turned on and stable for a period of time before the second stage is turned on to supply the power at the second voltage to the micro-controller.

Abstract: A converter includes first and second coupled inductors. A first phase includes first high side and low side switches connected to the first inductor. A second phase includes second high side and low side switches connected to the second inductor. In discontinuous conduction mode, the controller determines, in response to the first high side switch being turned on and the second low side switch being turned off, that coupling between the first and second inductors is strong or weak based on whether body diode of the second low side switch will conduct if not prevented from conducting. The controller prevents second low side switch body diode conduction in response to the first high side switch being turned on when the coupling is strong, and does not prevent second low side switch body diode conduction in response to the first high side switch being turned on when the coupling is weak.

Abstract: A circuit starting method, a control circuit and a voltage reference circuit are provided. The control circuit includes an operational amplifier circuit and a comparison control circuit, wherein the operational amplifier circuit is arranged to establish an input reference voltage (VREF_INT) and an output reference voltage (VREF_OUT) by means of an operational amplifier (EA) and an external capacitor (C); and the comparison control circuit is arranged to, when the input reference voltage (VREF_INT) and the output reference voltage (VREF_OUT) are consistent, execute a toggle operation and output an enable signal (VREF_OK) to the operational amplifier (EA) so as to shut down the operational amplifier (EA).

Abstract: A PFC circuit is provided. A bridge rectification circuit receives an AC voltage and generates a rectified AC voltage. A power converter converts the rectified AC voltage to a first DC voltage, where the power converter includes a switch and supplies the first DC voltage to a DC bus to power a compressor. A current sensor detects an amount of current. A control module, while operating in a correction mode: based on the rectified AC voltage, a phase angle of the rectified AC voltage, a second DC voltage of the DC bus, or the detected amount of current, control operation of the switch to transition between operating in a high activity mode and an inactive or low activity mode; transition the switch between open and closed states while in the high and low activity modes; and maintain the power converter in an OFF state while in the inactive mode.

Abstract: A power source apparatus for supplying power to a load includes a switch and a controller. The controller detects voltage applied to the switch. The controller further switches a state of the switch from OFF to ON when the detected voltage is equal to or smaller than a predetermined threshold value.

Abstract: A charging method of a portable electronic device, adapted to charge a battery module of a portable electronic device, the charging method comprising detecting a battery voltage and a charging current of the battery module; determining whether the portable electronic device operates at a constant current mode according to the battery voltage; entering an over voltage protection charging loop while the portable electronic device operates at the constant current mode and allows the battery module to be charged up at a maximum charging voltage, and leaving the over voltage protection charging loop while the charging current is smaller than a predetermined current, wherein the maximum charging voltage is gradually decreased according to a comparison result between the battery voltage and an overcharging protection voltage; and setting the maximum charging voltage as a full charge voltage while leaving the over voltage protection charging loop.

Abstract: The disclosure relates to a controller for a power converter, the power converter comprising a first switch and a second switch, wherein the controller is configured to receive a first control signal based on a first drain-to-source voltage of the first switch; receive a second control signal based on a second drain-to-source voltage of the second switch; derive a first switch control signal based on the first control signal and control the first switch by providing the first switch control signal to the first switch; derive a second switch control signal based on the second control signal and control the second switch by providing the second switch control signal to the second switch; wherein the first switch control signal and the second switch control signal each comprises turn-on edges and turn-off edges. Furthermore, disclosure also relates to corresponding methods, a non-transitory computer readable medium.

Abstract: A method for operating a photovoltaic system which includes solar panels, at least one DC-DC converter and an intermediate DC circuit, wherein the switching elements of the DC-DC converter are brought into a switching state which forms a permanent current path between the output of the solar panels and the intermediate circuit during a transition phase between an unloaded and loaded state of the solar panels.

Abstract: The present invention relates to a filter circuit for eliminating capacitive inrush current occurring in electromagnetic coil control circuits controlling the actuator coil of electromagnetic contactors or relays. The filter circuit comprises input terminals to be connected with a direct current voltage, a first output terminal to be connected with a first terminal of the inductive load and a second output terminal to be connected to a second terminal of the inductive load, a first diode, wherein the cathode of the first diode is connected to said first output terminal and to said first input terminal, a second diode, wherein the anode of the second diode is connected to said second output terminal, and a filter capacitor which is connected between said second input terminal and to a node which interconnects the anode of said first diode and the cathode of said second diode.

Abstract: Techniques are described for ripple detection and cancellation in switching voltage regulator circuits. For example, in a switching voltage converter, a voltage is up-converted or down-converted by switching high side and low side switches and passed through a low-pass filter for averaging. While the act of switching can result in conversion of the voltage with good efficiency, it also typically generates ripples on the output voltage, which can be undesirable in some applications. Embodiments use the switching voltage, the output voltage, and a feed-forward loop to generate a current cancellation signal to have particular gain, timing, and polarity that effectively emulates the complement of the inductor ripple current. The cancellation current signal can be injected into the output node, such that the cancellation current signal sums with the inductor ripple current at the output node, thereby at least partially cancelling the effect of the inductor ripple current.

Abstract: System and method for regulating one or more currents. The system includes a system controller, an inductor, a first resistor, a switch and a first diode. The system controller includes a first controller terminal and a ground terminal, the system controller being configured to output a drive signal at the first controller terminal. The inductor includes a first inductor terminal and a second inductor terminal, the first inductor terminal being coupled to the ground terminal, the second inductor terminal being coupled to one or more light emitting diodes. The first resistor includes a first resistor terminal and a second resistor terminal, the first resistor terminal being coupled to the ground terminal. The switch is configured to receive the drive signal and coupled to the second resistor terminal. The first diode includes a first diode terminal and a second diode terminal and coupled to the first resistor.

Abstract: Provided is a display device including a plurality of light sources configured to be driven by a driving voltage, turned on during an on section, and turned off during an off section, a display panel configured to display an image by using light outputted from the light sources, a voltage converter connected to the light sources and configured to generate the driving voltage, and a backlight control circuit including a light source driving circuit and a voltage drop circuit. The light source driving circuit includes a pulse generator including a control input terminal configured to receive a first voltage during the on section and receive a second voltage during the off section and output a control pulse signal to control a level of the driving voltage based on a voltage applied to the control input terminal. The voltage drop circuit applies the second voltage to the control input terminal during the off section. The second voltage is smaller than the first voltage.

Abstract: Enhanced common mode current reduction in three-phase inductors, transformers, and motor drive systems. A motor drive system includes an iron core transformer, a common-mode transformer coupled to a three-phase motor, and a variable speed drive providing a three-phase power signal to drive the three-phase motor, and coupled to the iron core transformer and the common mode transformer. The system includes a DC bus having a DC bus midpoint. The common-mode transformer includes a toroidal ferrite core, a first choke winding, a second choke winding, a third choke winding, a first coupling winding collocated with the first choke winding, a second coupling winding collocated with the second choke winding, and a third coupling winding collocated with the third choke winding. The first, second, and third coupling windings are coupled in parallel to one another. The coupled windings couple a neutral point of the iron core transformer to the DC bus midpoint.

Abstract: In accordance with embodiments of the present disclosure, a system may include a series combination of a boost converter and a power converter coupled together in series, such that the series combination boosts an input voltage to the series combination to an output voltage greater than the input voltage such that a voltage boost provided by the series combination is greater than a voltage boost provided by the boost converter alone. The system may also include an amplifier, wherein an input of the amplifier is coupled to an output of the series combination of the boost converter and the power converter.

Abstract: In the present invention a switching control circuit 130 has: a slope voltage generation unit 131 that generates slope voltages Vs1 and Vs2 that are opposite in phase and intersect each other; comparators 132 and 133 that respectively compare the slope voltages Vs1 and Vs2 and a control voltage Vc, and generate comparison signals S1 and S2; and a logical operation unit 134 that generates a step-down control signal D0 and a step-up control signal U0 from the comparison signals S1 and S2. The step-down control signal D0 and the step-up control signal U0 are used to control the switching of a step-up/step-down DC/DC converter.

Abstract: A method and apparatus for limiting or preventing electromagnetic interferences in a switching converter are presented. In particular, a power circuit provided with an active electromagnetic interference filter is presented. There is an electromagnetic interference EMI reduction circuit for use with a switching converter. This EMI reduction circuit has a current source and is adapted to regulate a voltage across the current source to provide a current having a constant average value. The switching converter is adapted to provide a converter current, and the current source constant average value may be substantially equal to an average value of the converter current. The circuit has a variable resistance; and an adjuster adapted to adjust the variable resistance based on the converter current. The adjuster may have a comparator, which is adapted to compare a voltage value at a terminal of a transistor switch, and a reference value.

Abstract: A peak current evaluation apparatus for an IC is provided. The peak current evaluation apparatus includes a pulse tuner and a testing circuit. The pulse tuner receives a clock signal, adjusts pulse width and duty ratio of the clock signal according to at least one predetermined parameter in order to generate a pulse signal with a stress voltage. The testing circuit is coupled to the pulse tuner. The testing circuit, which includes two input ports, receives the pulse signal at one of the two input ports in order to stress a testing device, measures the resistance value of the testing device, and calculates the peak current of the testing device when the resistance value increases and exceeds a threshold value.

Abstract: Provided are a boosting unit, a DC-DC converter including the boosting unit, and an electric vehicle. The DC-DC converter includes: a switch connected to an input voltage; a main diode connected to the switch; a regulating capacitor, a first terminal of the regulating capacitor being connected in series with the main diode, a second terminal of the regulating capacitor being connected to the input voltage, and the first terminal and the second terminal of the regulating capacitor serving as output terminals of the DC-DC converter; and a boosting unit, the boosting unit comprising a first inductor, a second inductor, a boosting capacitor, a first unidirectional conducting device, a second unidirectional conducting device, a third unidirectional conducting device and a fourth unidirectional conducting device. According to the embodiments of the present disclosure, voltage gain can be increased by replacing inductors in the ordinary DC-DC converter with the boosting unit.

Abstract: Disclosed examples include methods, integrated circuits and switch circuits including a driver circuit and a silicon transistor or other current source circuit coupled with a gallium nitride or other high electron mobility first transistor, where the driver operatives in a first mode to deliver a control voltage signal to the first transistor, and in a second mode in response to a detected overvoltage condition associated with the first transistor to control the current source circuit to conduct a sink current from the first transistor to affect a control voltage to at least partially turn on the first transistor.

Abstract: A predicted ripple in the feedback voltage of a switching converter is generated, based on the ripple over a certain number of recent switching cycles. The DC portion of the feedback voltage is filtered out. This predicted feedback voltage ripple is then added to a fixed reference voltage to create a compensated reference voltage. The compensated reference voltage is applied to the non-inverting input of an error amplifier, and the feedback voltage (having a DC component and ripple) is applied to the inverting input of the error amplifier. Thus, substantially the same ripple component is applied to both inputs and cancels out. Therefore, the output of the error amplifier is not affected by the ripple in the feedback voltage, and a non-rippling control voltage is generated by the error amplifier. As a result, the gain-bandwidth product of the converter can be increased for faster response to transients.

Abstract: Two versions of an isolated single stage converter AC/DC Power Factor Corrected (PFC) converter topology have been invented. One is with a full bridge rectifier at its input and the other is a True Bridgeless version. The two versions of the topology feature new configurations and circuitry including a simplified damper circuit and a clamp capacitor flipping circuit and control methods that allow them to realize improved single stage isolated power factor converters which are suitable for high power operation, features Zero Voltage Switching to maximize conversion efficiency and to minimize Electro-Magnetic Interference generation, does not need an additional circuit to limit the inrush current, achieves reasonably low input current Total Harmonic Distortion (THD), and is easy to control. The second version provides a true bridgeless single stage isolated power factor converter with even higher efficiency and lower input current THD.

Abstract: A DC-DC converter with a programmable pulse time limit. A charge pulse begins when the output voltage reaches a minimum threshold and terminates in response to a discharge indication, in which charge current flows through an inductive element while the charge pulse is provided. The discharge indication is provided to initiate a discharge pulse when the charge current reaches a peak threshold, which terminates in response to a reset indication. Current is discharged from the inductive element during the discharge pulse. A zero crossing detector provides the reset indication when the discharge current reaches a minimum level. A programmable timing circuit limits a duration of either one or both of the charge pulse and the discharge pulse to prevent hangup or excessive output voltage ripple. The DC-DC converter may include a memory that stores a digital value used to program the programmed time duration of the programmable timing circuit.

Abstract: A rapid discharge circuit comprises a detection circuit that is coupled to a power supply and that is configured to detect a voltage of a signal output by the power supply; a control circuit that is configured to generate a start signal in response to the detected voltage decreasing below a specified threshold value; an executing circuit having a first node that is coupled to the power supply and a second node that receives the start signal; a blocking circuit that has a first terminal coupled to a third node of the executing circuit and a second terminal coupled to an external circuit, where the executing circuit and the blocking circuit are configured to switch on in response to the start signal to form a current path for discharging the external circuit.

Abstract: In one embodiment, a pass MOSFET is coupled in series between an input voltage and a load, and a bypass capacitor is connected in parallel with the load. In response to a voltage step across the MOSFET, the MOSFET is adaptively controlled to conduct an in-rush current of 2ICL=2IL during the bypass capacitor 12 charging time, where ICL is the capacitive current and IL is the load current. This optimizes the in-rush current to achieve a minimum peak temperature of the MOSFET. In one embodiment, a ramp capacitor connected to the drain of the MOSFET is part of a feedback path that tracks the MOSFET drain voltage to control the gate voltage.

Abstract: An improved gated thyristor that utilizes less silicon area than IGBT, BIPOLARs or MOSFETs sized for the same application is provided. Embodiments of the inventive thyristor have a lower gate charge, and a lower forward drop for a given current density. Embodiments of the thyristor once triggered have a latch structure that does not have the same Cgd or Ceb capacitor that must be charged from the gate, and therefore the gated thyristor is cheaper to produce, and requires a smaller gate driver, and takes up less space than standard solutions. Embodiments of the inventive thyristor provide a faster turn off speed than the typical >600 ns using a modified MCT structure which results in the improved tail current turn off profile (<250 ns). Additionally, series resistance of the device is reduced without comprising voltage blocking ability is achieved. Finally, a positive only gate drive means is taught as is a method to module the saturation current using the gate terminal.

Abstract: System and method for regulating a power conversion system. An example system controller for regulating a power conversion system includes a first controller terminal associated with a first controller voltage and coupled to a first transistor terminal of a first transistor, the first transistor further including a second transistor terminal and a third transistor terminal, the second transistor terminal being coupled to a primary winding of a power conversion system, a second controller terminal associated with a second controller voltage and coupled to the third transistor terminal, and a third controller terminal associated with a third controller voltage. The first controller voltage is equal to a sum of the third controller voltage and a first voltage difference. The second controller voltage is equal to a sum of the third controller voltage and a second voltage difference.

Abstract: In order to reduce the cost of a switch-mode converter delivering a continuous voltage to the terminals of a load (Z), the present invention proposes a circuit having two windings (Lp, Ls) and a single magnetic core.

Abstract: These teachings apply with respect to a direct current (DC)-output converter and provide for adjusting a number of switching pulses per burst cycle as a function, at least in part, of converter output loading. This adjustment can be made by controlling burst frequency with respect to at least one predetermined threshold frequency. The predetermined threshold frequency can comprise a non-audible frequency such that the number of switching pulses is adjusted to prevent the burst frequency from itself constituting an audible signal. The adjustment of the number of switching pulses per burst cycle may only occur when the output loading is less than a predetermined level of loading. These teachings may also provide for clamping the pulse frequency for the pulses in each burst package to a particular value when dynamically controlling the number of pulses in each burst package. The aforementioned particular value may constitute, for example, a highest available switching frequency.

Abstract: Apparatus and methods for a bias supply circuit to support power supply including a switched-mode voltage converter cascaded with an n-channel-based linear regulator are provided. In an example, a cascaded power supply system can include a switched-mode DC-to-DC power converter, including an input voltage node, a first stage output voltage node, and a bootstrapped floating bias voltage node, and a linear regulator circuit. The linear regulator circuit can include an n-channel field-effect transistor (NFET) pass transistor, including a drain terminal coupled to the first stage output voltage node, a gate terminal, and a source terminal configured to provide a second-stage output voltage, and a gate driver circuit, including a driver output coupled to the gate terminal of the NFET pass transistor, and a high side supply node configured to receive a bias voltage generated from the bootstrapped floating bias voltage node.

Abstract: A switching power converter provides regulated voltage to a load. The switching power converter comprises a transformer including a primary winding coupled to an input voltage and a secondary winding coupled to an output of the switching power converter. The switching power converter further comprises a power switch coupled to the primary winding and a rectifier coupled to the secondary winding. Current is generated in the primary winding responsive to the power switch being turned on and not generated responsive to the power switch being turned off. A detection circuit measures a voltage across the rectifier. If the detection circuit detects a decrease in the voltage across the rectifier outside of a blanking period, the detection circuit generates a current pulse in the secondary winding of the transformer.

Abstract: A charge pump includes: a first diode that is connected to a first node; a second diode that is connected to a second node; a pump capacitor that is connected to a third node to which the first diode and the second diode are connected; a power supply capacitor that is connected to the pump capacitor; a third diode that is connected between the pump capacitor and the power supply capacitor; and a zener diode that is connected in parallel to the third diode and the power supply capacitor. A power supply device decreases a ripple of an output current using a ripple reduction signal.

Abstract: A switching circuit with reverse current prevention for use in a Buck converter includes a power switch coupled to a coupling node, which is an interconnection point of a power switch, an inductor and a freewheeling diode of the Buck converter. The inductor is coupled between the coupling node and an output of the Buck converter, and the freewheeling diode is coupled between coupling node and an output return of the Buck converter. A controller is coupled to receive a feedback signal to control switching of the power switch to regulate a transfer of energy from the input to the output of the Buck converter. A reverse current prevention circuit is coupled to detect a reverse current condition of the power switch to generate an inhibit signal to inhibit the power switch from receiving a drive signal to prevent a reverse current through the power switch.