Abstract: A power supply circuit is provided which includes a first booster to boost a power supply voltage supplied from a battery and generate a first boosted voltage, a second booster to boost the power supply voltage at a higher multiplication factor than the first booster and generate a second boosted voltage, a power supply selection circuit to output the first boosted voltage or the second boosted voltage, a first smoothing capacitor placed at an output end of the power supply selection circuit, and a second smoothing capacitor placed at an output end of the second booster.

Abstract: A voltage/current control apparatus and method are disclosed. The apparatus includes a low-side field effect transistor (FET) having a source, a gate and a drain, a high-side field effect transistor (FET) having a source, a gate and a drain, a gate driver integrated circuit (IC), a sample and hold circuit, and a comparator configured to produce a trigger signal at the output when a sum of the first and second input signals is equal to a sum of the third and fourth input signals, wherein the trigger signal is configured to trigger a beginning of a new cycle by turning the gate of the high-side FET “on” and the gate of the low-side FET “off”.

Abstract: A device of inductance detection, which includes: a controller, a current pulse generator, and a detector. The controller generates a control signal and an enable signal to the switching regulator according to a judge signal. The switching regulator then generates an output voltage. The current pulse generator is coupled to the controller and generates a current pulse signal to the object according to the control signal. The detector is coupled to the object and the current pulse generator, and is used to detect a reflective signal responded by the object after the object receives the current pulse signal. The detector then generates a judge signal according to the reflective signal.

Abstract: Embodiments for at methods, apparatus and systems for operating a voltage regulator are disclosed. One method includes generating, by a switching controller, a switching voltage through controlled closing and opening of a series switch element and a shunt switch element. Further, the method includes generating, by a switchable output filter, a regulated output voltage by filtering the switching voltage, wherein the switchable output filter comprises a plurality of capacitors that are selectively included within the switchable output filter.

Abstract: A control circuit for a switching regulator includes a clock circuit, a pulsewidth modulation (PWM) circuit, and a reduction monitor. The clock circuit provides a clock signal at a variable frequency. The PWM circuit produces a drive signal of at least a first predetermined duration once every period of the clock signal. The reduction monitor controls the clock circuit to reduce the variable frequency in response to a sense signal that indicates that at least one of a voltage and a current is outside a limit during the first predetermined duration of said drive signal.

Abstract: A system and method for regulating power flow and limiting inductor current in a bidirectional direct current (DC)-to-DC converter is provided. In one aspect, a feedback circuit is provided to control power flow and/or limit inductor current based on the input/output voltage and/or current conditions in the bidirectional DC-DC converter. During a boost mode of operation, the duty cycle of a low-side switch within the bidirectional DC-DC converter is reduced, based on an analysis of the high-side voltage and positive inductor current. Further, during a buck mode of operation, the duty cycle of the low-side switch is increased, based on an analysis of the low-side voltage and negative inductor current. Moreover, the duty cycle of the low-side switch is adjusted, such that, the high-side voltage, low-side voltage and inductor current (in both directions) do not exceed preset threshold and the bidirectional DC-DC converter returns to a steady state.

Abstract: A switching power converter current limit reference circuit generates an output-referred input current reference (or an input-referred output current reference) which takes into account a converter's input voltage, output voltage, and efficiency, thereby enabling implementation of a DC, or average, input current regulation scheme. A reference current (Iref) is provided which represents the desired average current limit. Circuitry multiplies Iref and the complement of the converter's duty cycle D (1-D) together. When Iref represents a desired input current limit, the resulting product represents the average output current achievable when Iref=Iin for the prevailing duty cycle D. When Iref represents a desired output current limit, the resulting product represents the average input current achievable when Iref=Iout for prevailing duty cycle D.

Abstract: A constant-on-time generation circuit for generating a turn-on signal to a buck is disclosed. The constant-on-time generation circuit includes a capacitor, a current source, a second resistor, an inverter, a transistor coupled to the inverter for generating a set turn-on signal according to a first front-end driver signal of the buck converter, a comparator including a negative input terminal coupled to a reference voltage, a positive input terminal coupled to the second resistor and the current source, and an output terminal, for comparing the reference voltage with the set turn-on signal to output a comparison result, and an SR-latch for outputting a turn-on signal to a driver stage circuit of the buck converter according to a trigger signal of the buck converter and the comparison result.

Abstract: Systems and methods for increasing power measurement accuracy for power factor correction (PFC) are disclosed. An exemplary method may include providing a PFC circuit for a power supply, the PFC circuit having a bulk capacitor connected to a rectified AC line. The method may also include measuring output load. The method may also include enabling AC wave skipping if the measured output load drops below a threshold value.

Abstract: The present invention is directed to an electrical supply apparatus having an input for connecting the electrical supply apparatus to a mains supply which provides an alternating voltage as input voltage, having an output for connecting the electrical supply apparatus to a load, wherein the output provides a DC voltage as output voltage, having a rectifier which rectifies the input voltage to form a rectified input voltage, having a PFC module which comprises a smoothing device for smoothing the rectified input voltage and an active power factor correction device, wherein the power factor correction device is designed to form a time-dependent supply current for the smoothing device depending on a time-dependent current form signal in such a way that a time-dependent input current in the PFC module is matched to the current form signal, wherein the current form signal is produced by an analogue circuit.

Abstract: A voltage regulator circuit includes: a first pulse generator configured to output a pulse whose level remains unchanged when an input signal of a first circuit is in a first period, and whose level changes from a second level to a first level when an edge of the input signal of the first circuit is detected after the first period; a second pulse generator configured to output a pulse from a time that the pulse output by the first pulse generator becomes the first level until a second period elapses; a first field-effect transistor having a source connected to a power supply potential node, and a drain connected to a power supply potential terminal of the first circuit; and a first switch configured to cause a potential at a gate of the first field-effect transistor to be a first potential.

Abstract: A control circuit for a power converter is disclosed, having a shared pin, a driving circuit, a current source, a sampling circuit, and a signal processing circuit. The shared pin is used for coupling with an output end of the power converter through a resistor. The driving circuit is used for conducting a switch of the power converter. The current source provides a current to the resistor through the shared pin. The sampling circuit samples the signal on the shared pin for generating a first sampling value and a second sampling value. When the difference between the first sampling value and the second sampling value is less than a predetermined value, the signal processing circuit configures the driving circuit to adjust at least one of the conduction time and the conduction frequency of the switch according to an output signal of the power converter received from the shared pin.

Abstract: In various embodiments a circuit is provided including: an input terminal to receive an input voltage; a switch, a first controlled input of which being coupled to the input terminal; an inductor, a first terminal of which may be coupled in series to a second controlled input of the switch; a freewheeling diode, wherein a first diode terminal may be coupled with the second controlled input of the switch and with the first terminal of the inductor, and wherein a second diode terminal may be coupled with a reference potential; a capacitor coupled with a second terminal of the inductor; and a controller configured to operate the switch and the inductor in continuous current mode to charge the capacitor.

Abstract: The invention discloses a voltage regulating apparatus which includes: an output stage providing the apparatus with an output voltage and producing a partial voltage of the output voltage; an error amplifier coupled to the output stage and comparing the partial voltage with a reference to produce a first voltage; a PWM unit coupled to the error amplifier and comparing the first voltage with a voltage signal to produce second and third voltages; a selection unit coupled to the error amplifier and the PWM unit and outputting a fourth voltage equalling either the first or the second voltage; a first transistor coupled to the selection unit and receiving the fourth voltage and a DC voltage; and a second transistor coupled to the PWM unit, the first transistor, and a ground and receiving the third voltage; wherein a connection point of the first and second transistors is connected to the output stage.

Abstract: Embodiments described include voltage generators having reduced or eliminated cross current. Dynamic adjustment of a low or high threshold voltage used in a voltage generator is described. Use of a folded cascade amplifier in a voltage generator is also described.

Abstract: A buck converter and a switching regulator capable of suppressing a ripple voltage under light load conditions. The buck converter has NMOS transistors QN2 and QN3 that are connected in series between input voltage VIN and the ground, inductor L1 that is connected to node SW where transistors QN2 and QN3 are connected, comparator COMP2 that compares respective voltages of node N1 and node N2 so as to decide on time of transistor QN2, and current detection circuit 100 that detects reverse current Ig flowing to the ground from inductor L1 via node SW and transistor QN3. When current detection circuit 100 detects reverse current Ig, voltage of node N1 of comparator COMP2 is reduced by variable circuit 110 in order to reduce the on time of transistor QN2.

Abstract: A power architecture receives an input signal at an input node and converts the input signal into an intermediate signal with a power conversion stage. The power conversion stage supplies the intermediate signal to an output node of the power conversion stage where the intermediate signal is filtered with an operating capacitance coupled to the output node. A hold-up capacitance is charged, and when a loss of the input signal is detected, the hold-up capacitance is coupled to the input node.

Abstract: A regulated, power supply system is described using multiphase DC-DC converters with dynamic fast-turnon, slow-turnoff phase shedding, early phase turn-on, and both load-voltage and drive-transistor feedback to pulsewidth modulators to provide fast response to load transients. In an embodiment, a system master can automatically determine whether all, or only some, slave phase units are fully populated. The programmable system includes fault detection with current and voltage sensing, telemetry capability, and automatic shutdown capability. In an embodiment, these are buck-type converters with or without coupled inductors, however some of the embodiments illustrated include boost configurations.

Abstract: Disclosed herein are bias voltage generating circuits configured for switching power supplies, and associated control methods. In one embodiment, a bias voltage generating circuit can include: (i) a first control circuit configured to compare a drain-source voltage of a switch against a bias voltage; (ii) a capacitor, with the bias voltage across the capacitor; (iii) a second control circuit configured to control the switch, and that is enabled when the bias voltage is at least as high as an expected bias voltage; (iv) the first control circuit being configured to control the capacitor to charge when the drain-source voltage of the switch is greater than the bias voltage; and (v) the bias voltage being less than an overvoltage protection voltage when the capacitor charges, and where the overvoltage protection voltage comprises a voltage that is a predetermined amount higher than the expected bias voltage.

Abstract: A power converter includes a power converting unit and a driving circuit. The power converting unit generates a DC output voltage based on a pull up driving signal, a pull down driving signal, and a DC input voltage. The driving circuit compensates for an inductor peak current, and performs in a pulse-frequency-modulation (PFM) mode and a pulse-width-modulation (PWM) mode to generate the pull-up driving signal and the pull-down driving signal based on the DC output voltage and the compensated inductor peak current. The power converter performs a mode transition between the PFM and PWM modes at a uniform load current, even when a magnitude of the DC output voltage varies.

Abstract: A bootstrap gate driver including a load indication unit, a bootstrap gate-drive unit and a drive-control unit is provided. The load indication unit is configured to generate a load indication signal in response to a state of a load. The bootstrap gate-drive unit is configured to drive a switch-transistor circuit in response to an inputted pulse-width-modulation (PWM) signal, wherein the switch-transistor circuit has a high-side driving path and a low-side driving path. The drive-control unit is coupled to the load indication unit and the bootstrap gate-drive unit, and configured to enable or disable the high-side driving path in response to the load indication signal. In the invention, the operation of the low-side driving path is not affected by enabling or disabling the high-side driving path.

Abstract: Systems and methods are disclosed to detect current for an output load with an inductor. The system includes a high side power transistor a low side power transistor coupled to the high side power transistor; and a controller coupled to the high and low side power transistors.

Abstract: A power converter includes an input and an output. A regulation circuit is coupled between the power converter input and the power converter output. The regulation circuit is coupled to receive a feedback signal representative of the power converter output. The feedback signal has a first feedback state that represents a level at the power converter output that is above a threshold level and a second feedback state that represents a level at the power converter output that is below the threshold level. An oscillator is included in the regulation circuit that provides an oscillation signal that cycles between two states. The regulation circuit is coupled to be responsive to the oscillation signal and to a change between the first and second feedback states to enable or disable a flow of energy from the power converter input to the power converter output.

Abstract: It is an object to obtain a detection circuit for detecting feedback voltage without variation in output voltage/current or in output voltage by the operation temperature, and a power supply circuit including thereof. A power supply circuit includes a detection circuit, an amplifier circuit outputting an output voltage, a control circuit, and a divider circuit. The detection circuit includes first and second reference voltage generation circuits and an input signal adjustment circuit. The control circuit is electrically connected to the amplifier circuit and includes the detection circuit, an error amplifier circuit, a pulse width modulation driver, a triangle-wave generation circuit, and a capacitor. The divider circuit is electrically connected to the amplifier circuit and the control circuit and inputs a voltage obtained by dividing the output voltage to the second reference voltage generation circuit.

Abstract: A control circuit for a power converter includes a shared pin, a driving circuit, a current source, a sampling circuit, and a signal processing circuit. The shared pin is coupled with an output end of the power converter through a resistor. The driving circuit conducts a switch of the power converter. The current source provides a current to the resistor through the shared pin. The sampling circuit samples the signal on the shared pin for generating a first sampling value and a second sampling value. The signal processing circuit calculates a first difference between the first sampling value and a first reference value, and a second difference between the second sampling value and a second reference value. When the difference between the first difference and the second difference is less than a predetermined value, the signal processing circuit may therefore configure the conduction time or frequency of the switch.

Abstract: A SEPIC converter with over-voltage protection includes a high-side inductor that connects a node Vw to a node Vx. The node Vx is connected, in turn to ground by a power MOSFET. The node Vx is also connected to a node Vy by a first capacitor. The node Vy is connected to ground by a low-side inductor. A rectifier diode further connects the node Vy and a node Vout and an output capacitor is connected between the node Vout and ground. A PWM control circuit is connected to drive the power MOSFET. An over-voltage protection MOSFET connects an input supply to the PWM control circuit and the node Vw. A comparator monitors the voltage of the input supply. If that voltage exceeds a predetermined value Vref the comparator output causes the over-voltage protection MOSFET to disconnect the node Vw and the PWM control circuit from the input supply.

Abstract: Consistent with an example embodiment, there is a controller for a resonant converter, wherein the controller is configured to operate the resonant converter in a high power mode of operation by adjusting a first control parameter to vary the output power and a low power mode of operation by adjusting a second control parameter to vary the output power. The controller is configured to set the value of the first control parameter when changing over between the high power mode of operation and the low power mode of operation such that the output power is substantially consistent during the changing over.

Abstract: A semiconductor integrated circuit includes: a first switching element and a second switching element that are provided in series between a first power line and a second power line; a power supply circuit that outputs a given output voltage by on/off controlling the first switching element and the second switch element; a current detection circuit that detects a current corresponding to an output load current of the power supply circuit; a switching time control circuit that controls a switching time defined by a power supply voltage and the output voltage based on a current value detected by the current detection circuit; and a switching element control circuit that controls the first switching element and the second switching element based on an output signal of the switching time control circuit.

Abstract: A buck switching voltage regulator, with high side and low side switching transistors, includes mode control circuitry for switching between PWM and PFM modes based on sensing inductor current through the low side switch during switching cycle OFF times (inductor discharge). Mode switching is based on comparing a an integrated inductor current sense signal with an integrated reference signal corresponding to a predefined average inductor current IAVE. In one embodiment, a mode switching condition is based in part on [IVALLEY=21AVE?IPEAK], where IPEAK is a detected peak inductor current at the beginning of an OFF time, and IVALLEY is an inductor current value determined by IAVE and IPEAK.

Abstract: An electric protection mechanism for a light controller includes an overload protection device. The overload protection device includes a lamplight controller, a power controller, and a load detector. A current sensor is provided between the power controller and a light. An overload detector is provided to detect the state of the electric current anytime. Once abnormal current is outputted to the light, the power controller immediately shuts its output and informs the lamplight controller of the abnormal current. The lamplight controller will reset its process, such as to shut down the power source or to press the button so as to return to normal. Thus, the lamplight controller, a light adjuster or a remote controller can be protected. The present invention provides an overload protection function, and it is safe to use the present invention.

Abstract: A buck-boost power converter switches the switches thereof with a novel sequence and extends the switching periods of the switches to reduce the switching loss and conduction loss when the input voltage thereof approaches the output voltage thereof. The influence of the load current of the power converter on the duty thereof is taken into account to switch the power converter between modes at correct time points, so as to prevent the output voltage from being affected by the mode switching.

Abstract: A power converter and method of controlling the same for selected modes of operation. In one embodiment, the power converter includes a first power switch coupled to a source of electrical power and a second power switch coupled to the first power switch and to an output terminal of the power converter. The power converter also includes a controller configured to control an operation of the first and second power switches during selected modes of operation.

Abstract: Generated are an error signal representative of a difference between a signal representative of the output voltage of a current mode switching power supply and a reference voltage, and a peak current threshold signal that is indicative of a peak current that should be reached in an inductor within the power supply during each cycle of a periodic clock signal and that has a level that is based on the error signal. A switch control signal regulates the voltage output of the power supply by closing and then opening a power switch during each cycle of the periodic clock signal. Timing of opening is based on the peak current threshold signal. Negative slope compensation causes the switch control circuit to delay opening the power switch during each cycle of the periodic clock signal in an amount that decreases with increasing duty cycles of the switch control signal.

Abstract: A current sense circuit for use with a switching regulator including a first transistor, connected to an inductor, configured to switch a current flowing through the inductor from a power supply; and a second transistor, connected to a node to which the inductor and the first transistor are connected, configured to be turned on during a part of an OFF period of the first transistor. The current sense circuit includes a current generator configured to generate a sense current corresponding to a current flowing through the first transistor; a hold circuit configured to output a voltage corresponding to the sense current during an ON period of the first transistor, and to hold and output the voltage corresponding to the sense current during the OFF period of the first transistor; and an output transistor configured to generate a current corresponding to the voltage output by the hold circuit.

Abstract: A current mode synchronous rectification direct current (DC)/DC converter according to the present invention includes: a soft start function unit (in FIG. 1, a reference voltage generation unit (104) enabling a reference voltage REF to slowly increase while starting), for inhibiting a target value of an output voltage VO to be lower than that at a normal action while starting; and an output stabilization function unit (in FIG. 1, a frequency variable type oscillator (110A) generating a clock signal CLK and a slope voltage SLOPE through an oscillation frequency corresponding to a reference voltage REF), for performing at least one of waiting for start of a switching action and reduction of a drive frequency while starting.

Abstract: A switching direct current (DC)-to-DC converter includes a charge pump circuit with a flying capacitor (104) and a switching circuit (106). The switching circuit (106) has an ON resistance (Ron) and is configured and arranged to boost an input voltage (Vin) by operating in each of a charging mode (loading) during which charge is provided from the flying capacitor (104) to an output voltage (Vout) and a discharging mode (storing) during which charge is not provided from the flying capacitor (104) to the output voltage (Vout). A determination circuit (102) is configured and arranged to determine a ratio between a discharge rate (308) and a charge rate (310). The discharge rate (308) and the charge rate (310) both correspond to a rate of change for the output voltage of the switching DC-to-DC converter. An ON resistance circuit (102) module is configured and arranged to adjust the ON resistance (Ron) of the charging mode (loading) and to change the determined ratio to a target ratio.

Abstract: A DC-DC converter including a Pulse Width Modulation (PWM) controller for converting an input voltage into an output voltage is provided. The PWM controller includes a first comparator, receiving a compensated error signal and a ramp signal, wherein when the compensated error signal exceeds the ramp signal, the first comparator generates a trigger signal. The PWM controller further includes a PWM generator coupled to the first comparator, providing a timing signal according to the trigger signal to control the operation of the DC-DC converter.

Abstract: A DC-DC converter or the like capable of generating a stable output voltage is provided. A control circuit 11 of a current mode step-down DC-DC converter 1 includes a slope compensation circuit SC and an offset circuit IF1. The slope compensation circuit SC adds an increase gradient m2 due to slope compensation to an increase gradient of a coil current waveform Vsense in a range wherein an ON period Ton of a switch SW1 exceeds ½ of an operating cycle T. An offset circuit IF1 applies an offset voltage Voffset which becomes smaller depending on the ON period Ton in excess of ½ of an operating cycle T, to a coil current waveform Vsense.

Abstract: A constant frequency ON-time control system applied to a voltage regulator is disclosed. The voltage regulator determines a time length of an input voltage inputted thereto according to an ON-time and thereby regulates an output voltage. The constant frequency ON-time control system includes a constant frequency ON-time control circuit for computing the ON-time according to a system duty cycle of the voltage regulator and a frequency setting parameter and a frequency setting parameter adjusting circuit for generating a frequency setting parameter adjust value according to an OFF-time corresponding to the ON-time and taking a result of operation between the frequency setting parameter adjust value and a preset frequency setting parameter as the frequency setting parameter. The frequency setting parameter adjusting circuit uses the frequency setting parameter adjust value to change the result of operation for varying the frequency setting parameter when the OFF-time is shorter than a reference value.

Abstract: A circuit for detecting fault conditions in a supply circuit includes a monitoring circuit and a comparator circuit. The monitoring circuit is operable to output a detection signal related to a control signal for the switched mode power supply. The control signal may be configured to operate at least one switch of the supply circuit between alternating activated and deactivated states to supply power to a load. The comparator circuit is operable to compare the detection signal to a range defined by first and second thresholds and output a fault signal according to a relationship of the detection signal to the range over a time period. Related methods of operation are also discussed.

Abstract: A DC-DC voltage converter operating in zero-voltage switching mode with a switching threshold includes a plurality of interlaced cells, each cell having at least two controlled switches that are configured to be alternately closed and open, and each cell having an inductor in which an output current from the cell flows. The converter also includes a clock with a given switching period configured for triggering the switching of the switches between upper and lower control thresholds. A method for closed-loop control of the converter includes measuring, for each cell, an overrun period, determining a correction time corresponding to a minimum overrun period measured for the plurality of cells during an interlacing cycle, calculating an optimized switching period for the clock, and applying the optimized switching period to the clock to provide closed-loop control of the interlacing of the output currents from the plurality of cells of the converter.

Abstract: A boost converter comprises an inductance that receives an input signal. A switch controls current supplied by the inductance to a load. A power factor control module comprises a mode control module that selects an operating mode of the boost converter and a switch control module that switches the switch at a frequency. The frequency is equal to a first frequency when the mode control module selects a continuous mode and equal to a second frequency when the mode control module selects a discontinuous mode. The first frequency is greater than the second frequency.

Abstract: A semiconductor device is described that includes a switch to switch a load current path on and off according to an input signal. The device further includes an over-current detector to compare a load current with a threshold and to signal an over-current when the load current reaches or exceeds the threshold. The device further includes a control unit to set the threshold to a higher value while in a first state of operation and to a lower value while in a second state of operation, and to at least temporarily switch the switch off when an over-current is signalled, change from the first state of operation to the second state of operation when a first pre-defined time span has elapsed, and to change from the from the second state of operation to the first state when the switch is off for more than a second pre-defined time span.

Abstract: A switching power converter including an upper-bridge switch, a lower-bridge switch, an impedance circuit, a first control circuit, a second control circuit and a logic circuit is provided. The impedance circuit generates an output voltage and a sensing current according to a conductive state of the upper-bridge switch and the lower-bridge switch. The first control circuit generates a first pulse signal according to the output voltage. The second control circuit has a first mode and a second mode for generating a second pulse signal and a third pulse signal individually. Furthermore, the second control circuit uses different threshold values in different modes to determine whether to switch the mode thereof, so as to form a hysteretic effect in mode switching. The logic circuit controls the upper-bridge switch by the first pulse signal, and controls the lower-bridge switch by the second pulse signal or the third pulse signal.

Abstract: Methods and systems are disclosed for an integrated voltage regulator with open loop digital control for power stepping. In one aspect, a method for regulating an output voltage includes receiving data indicative of a power setting associated with an identified state of an electrical circuit, the power setting based on a load current demand of the electrical circuit in the identified state, enabling one or more parallel driver segments based on the received data indicative of the power setting. The method further includes sourcing by the enabled one or more parallel driver segments sufficient current to meet the load current demand of the electrical circuit in the identified state while maintaining the output voltage at a predetermined voltage level, and providing the output voltage to the electrical circuit at the predetermined voltage level.

Abstract: A DC-DC converter and a method of controlling an inductor-based switching-mode DC-DC converter in a discontinuous conduction mode are disclosed. In one aspect the method includes providing a DC-DC converter having a first and second switching elements, and, in each conversion cycle, first, turning on a first switching element, while maintaining a second switching element in off state, thereby increasing the current through an inductor. The method also includes detecting when a voltage signal at one connection node of the inductor reaches a first threshold value for the first time after the start of the conversion cycle, and turning on the second switching element, while maintaining the first switching element in off state, thereby decreasing the inductor current.

Abstract: A switch mode power supply having an output terminal configured to provide an output voltage which is regulated to an output target, the switch mode power supply has a first switch and a control circuit. When the output voltage increases to a first threshold voltage, the control circuit is configured to turn OFF the first switch until a time period expires.

Abstract: When the switching frequency of a constant on-time power converter decreases to a threshold, the power converter is switched from the original operation of triggering a constant on-time of a high-side switch responsive to the output voltage of the power converter reaching a valley point to the operation of triggering a constant off-time of the high-side switch responsive to the output voltage reaching a peak point, to thereby prevent the power converter from operating in an audio frequency range.

Abstract: A control circuit used to control a DC-DC converter includes a duty cycle control unit to control a duty cycle of the DC-DC converter and a hysteretic control unit to maintain a voltage at an output of the DC-DC converter within a narrow range during certain operational time periods. The hysteretic control unit may maintain the converter output voltage within the range by alternately enabling and disabling the duty cycle control unit based on feedback from the DC-DC converter output. In at least one embodiment, the control circuit is used within LED driver circuitry for driving a plurality of LED channels.

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.