Abstract: A power converter is provided. A driver circuit is connected between a controller circuit and a switch circuit. The switch circuit is connected to an inductor. The inductor is connected in series with a first capacitor and grounded through the first capacitor. A first comparison input terminal of a first comparator is connected to an output terminal between the inductor and the first capacitor. A second comparison input terminal of the first comparator is grounded through a second capacitor. The controller circuit outputs a control signal for controlling the driver circuit to drive the switch circuit according to a comparison signal outputted by the first comparator. A reference current source provides a reference current to the second capacitor. A first terminal of a first resistor is connected to the second capacitor. A second terminal of the first resistor is coupled to a reference potential.

Abstract: A device includes a first transistor connected between a first node and an output terminal and a first current source connected between the first node and a supply rail. A circuit includes a second current source connected between the supply rail and a second node, an operational amplifier having a non-inverting input configured to receive a potential set point, and a second transistor connected between the second node and an inverting input of the operational amplifier. An output of the operational amplifier is connected to a control terminal of the second transistor and further connected to a control terminal of the first transistor.

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 circuit arrangement includes two switching group series circuits of switch assemblies, switch-mode power supply units, and two capacitor bridges connecting the switching group series circuits. Each switch assembly has a parallel circuit of a semiconductor switch and a freewheeling diode as well as a driver for actuating the semiconductor switch. Each switch-mode power supply unit is associated with a switch pair of semiconductor switches and supplies the drivers of both semiconductor switches of the switch pair with energy. Each switch pair is formed by a semiconductor switch of a first switching group series circuit and a semiconductor switch of a second switching group series circuit. A power convertor module having the circuit arrangement is also provided.

Abstract: A switching converter, control method control circuit thereof are disclosed. The switching converter converts a DC input voltage into a DC output voltage. The control circuit comprising: a compensation module, generating a ramp signal; a comparator, compares a first superimposed signal related to the DC output voltage with a second superimposed signal related to an error signal between the DC output voltage and the ramp signal; a first RS flip-flop generates a pulse width modulation signal in accordance with a set signal and a reset signal, obtains a constant on time in accordance with the reset signal, and obtains an off time related to the DC output voltage; and a driving module which converts the pulse width modulation signal into a switching control signal, wherein the compensation module adaptively adjusts the slope of the ramp signal. The control circuit adopts an adaptive ramp signal to perform compensation.

Abstract: A semiconductor switch control circuit includes: a pulse signal generating part configured to generate a pulse signal which becomes a time reference for performing an ON/OFF control of a semiconductor switch; a drive current generating part configured to generate a drive current based on the pulse signal which the pulse signal generating part generates and to supply the drive current to a gate electrode of the semiconductor switch; a current detecting part configured to detect a drain current or a source current of the semiconductor switch; and a drive current control part configured to have a function of controlling a drive current which the drive current generating part generates based on the pulse signal which the pulse signal generating part generates and the current which the current detecting part detects.

Abstract: A load control device for controlling power delivered from an alternating-current power source to an electrical load may comprise a controllably conductive device, a control circuit, and an overcurrent protection circuit that is configured to be disabled when the controllably conductive device is non-conductive. The control circuit may be configured to control the controllably conductive device to be non-conductive at the beginning of each half-cycle of the AC power source and to render the controllably conductive device conductive at a firing time during each half-cycle (e.g., using a forward phase-control dimming technique). The overcurrent protection circuit may be configured to render the controllably conductive device non-conductive in the event of an overcurrent condition in the controllably conductive device.

Abstract: The power conversion device includes a multilevel boosting circuit and a smoothing capacitor for smoothing output voltage of the multilevel boosting circuit. The multilevel boosting circuit includes: a leg portion in which four semiconductor elements, i.e., a first diode, a second diode, a first switching element, and a second switching element are connected in series; and an intermediate capacitor connected between a connection point of the first diode and the second diode, and a connection point of the first switching element and the second switching element. When voltage of the smoothing capacitor becomes a reference voltage value or more, the control unit executes a protection mode to fix the first switching element and the second switching element in OFF states.

Abstract: An LED driver comprises a current source and a power supply configured to provide a power supply output voltage to the current source. The LED driver further comprises a controller configured to measure a voltage drop over the current source and to generate a feedback signal in response to the measured voltage drop. The power supply comprises a power supply regulator configured to regulate the power supply output voltage of the power supply between a minimum power supply output voltage and a maximum power supply output voltage, the power supply regulator comprising a power supply regulator input. The feedback signal is provided to the power supply regulator input, in a range from a first feedback signal value representing a minimum power supply output voltage to a second feedback signal value representing a maximum power supply output voltage.

Abstract: A controller for a motor includes a first processing circuit and a second processing circuit configured to communicate with each other. The first processing circuit is configured to execute a first operation amount calculation process, an operation process, and an output process. The first operation amount calculation process is a process of calculating a first operation amount. The output process is a process of outputting the first operation amount to the second processing circuit. The second processing circuit is configured to execute a second operation amount calculation process, a first use operation process, a second use operation process, and an elimination process.

Abstract: A controller includes a voltage sensing circuit configured to detect a voltage variation across a capacitor of a power converter, and a control circuit configured to calculate a current flowing through an inductor of the power converter based on the voltage variation across the capacitor of the power converter.

Abstract: A voltage converter with a high side power switch, having: an off control circuit, having a first input terminal configured to receive an input voltage, a second input terminal configured to receive an output voltage, a third input terminal configured to receive a current representing signal indicative of a current flowing through the high side power switch, a fourth input terminal configured to receive an on-set signal in response to an on operation of the high side power switch, and an output terminal configured to provide an off control signal to indicate an end of an on time period of the high side power switch; wherein the on time period of the high side power switch is regulated by the input voltage, the output voltage and the current representing signal.

Abstract: A circuit protective system. The system includes an output controlling enablement of a transistor and an input sensing an operational parameter associated with the transistor. The system also includes detection circuitry providing an event fault indicator if the operational parameter violates a condition. The system also includes protective circuitry disabling the transistor in response to the event fault indicator and subsequently selectively applying an enabling bias to the transistor; the enabling bias is selected from at least two different bias levels and in response to a number of event fault indications from the detection circuitry.

Abstract: Current flowing through an inductor on a primary side of a voltage converter is sensed and compared to a threshold peak current value to determine when to end an ON portion of the voltage converter. The secondary side of the voltage converter supplies an indication of output voltage for use in determining the threshold peak current value. On start-up the primary side detects when the indication of output voltage is supplied by the secondary side across on isolation channel. Prior to detecting the indicating is being supplied, the primary side uses an increasing threshold peak current as the threshold peak current value. After detection that the indication of output voltage is being provided by the secondary side, the threshold peak current value is based on the indication of the output voltage.

Abstract: A power conversion system includes a hybrid power converter phase unit including three voltage inputs, a voltage output, a pair of outer switches between the voltage inputs and voltage output, and a pair of inner switches between the voltage inputs and the outer switches. The power conversion system includes a controller in electrical communication with the inner and outer switches. The controller is configured to selectively disable or enable the inner switches by switching the inner switches OFF or ON. A method includes selectively disabling or enabling inner switches in a hybrid power converter phase unit with a controller such that the hybrid power converter phase unit is a 3-level converter when the inner switches are ON and enabled in a 3-level mode and a 2-level converter when the inner switches are OFF and disabled in a 2-level mode.

Abstract: A switch-mode power supply includes a pair of input terminals, a pair of output terminals, and at least one switch coupled between the input terminals and the output terminals. The power supply further includes an analog-to-digital converter (ADC) for converting a sensed analog current value at the output terminals to an output digital value, an interface for receiving a user configurable current setting, and a control circuit coupled with the interface, the ADC and the at least one switch. The control circuit is configured to determine a raw digital value of the ADC that corresponds to the received current setting by processing an iterative loop, and turn on and turn off the at least one switch according to the determined raw digital value and the output digital value of the ADC, to supply an output current at the pair of output terminals that corresponds to the received current setting.

Abstract: A switching regulator has an error amplifier supplying an error current, a phase compensation portion generating an error voltage, a clamper clamping the error voltage, a PFM detector supplying a comparison result signal of a first level or a comparison result signal of a second level based on the error current, an oscillator supplying a clock signal in response to the comparison result signal at the second level and fixing the clock signal in response to the comparison result signal at the first level, and a PWM converter turning on/off a switching element with a desired pulse width based on the error voltage and the output from the oscillator.

Abstract: An information handling system includes a power supply and a power assist unit. The power supply powers a power rail. The power assist unit includes a power storage element, a converter including a semiconductor device coupled to provide power from the power storage element to the power rail, and a controller configured to receive a load indication that indicates a power demanded by the load and to provide an intermediate output based upon the load indication. The controller includes a boost element to receive the intermediate output and to provide a controller output. The controller output is a sum of a bias voltage level provided by the bias element and the intermediate output. The controller output is coupled to a gate terminal of the semiconductor device. The converter provides power from the power storage element to the power rail in response to the controller output.

Abstract: A power source switch control device includes a detection circuit, a detection circuit, a detection circuit, and a detection circuit. The detection circuit detects forward voltage of a body diode of a FET, and the detection circuit detects forward voltage of a body diode of a FET. The detection circuit detects forward voltage of a body diode of a FET, and the detection circuit detects forward voltage of a body diode of a FET. A controller determines whether a defect of a power circuit has occurred based on results of the detection by the detection circuits to. Accordingly, the power source switch control device can appropriately detect defect of a switching element of a power source.

Abstract: Systems and methods for power conversion are described. Symmetric topologies and modulation schemes are described that may reduce common-mode noise. For example, a system may include a transformer including a first secondary winding and a second secondary winding; a rectifier, including a set of switches, that connects taps of the first secondary winding and the second secondary winding to a first terminal and a second terminal, wherein the rectifier is symmetric with respect to the first secondary winding and the second secondary winding; a battery connected between the first terminal and the second terminal; and a processing apparatus that is configured to control the set of switches to rectify a multilevel voltage signal on the transformer, including: selecting a modulation scheme from among two or more modulation schemes based on a measured voltage level of the battery.

Abstract: Controlling switching frequency of a switching power converter. At least some example embodiments are methods of operating a switching power converters, comprising: operating, by a primary-side controller, a switching power converter at a first frequency set by a resistor coupled to a first pin of the primary-side controller; and sensing a synchronization signal applied to the first terminal of the primary-side controller, the synchronization signal has a second frequency that is variable; and operating, by the primary-side controller, the switching power converter at the second frequency.

Abstract: A reconfigurable regulator includes an error amplifier configured to generate a difference signal indicative of a voltage difference between a reference analog signal and a feedback analog signal; a pulse width modulation generator configured to receive the difference signal, and to generate a first pulse width modulated signal in a linear mode and a second pulse width modulated signal in a switching mode; and a digital multiplexer (MUX) configured to receive a mode selection signal, the first pulse width modulated signal and the second pulse width modulated signal. The digital MUX outputs one of the first pulse width modulated signal or the second pulse width modulated signal based on the mode selection signal.

Abstract: A driver circuit for a laser diode is configured to pass a current. The circuit includes a charge-pump configured to generate an output boosted positive supply rail voltage. At least one switch is configured to couple the output of the charge-pump to a terminal of the laser diode and to isolate the positive supply rail from the terminal of the laser diode when the charge-pump is enabled.

Abstract: A charger device comprises a Single-Input-Multiple-Output (SIMO) device including a first transistor connected to an input and a first end of an inductor, a second transistor connected to ground and the first end of the inductor, a third transistor connected to a second end of the inductor and a first output, a fourth transistor connected to the second end of the inductor and a second output, and a controller connected to the SIMO device. The controller is configured to cause the SIMO device to charge the inductor based upon an input signal using a first power source coupled to the input during a first time period and discharge the inductor to charge at least one of the first power source and a second power source coupled to the first output during an unused time period.

Abstract: A method of controlling an isolated switching converter having an output voltage that is adjustable, can include: generating an output voltage setting signal characterizing an expected output voltage of a load; increasing a time period when an output voltage reference signal changes from a current value to the output voltage setting signal; and making overvoltage protection not trigger due to a change of the output setting signal.

Abstract: A voltage converter including first to fourth switches between a first voltage node and ground, fifth to eighth switches between the first voltage node and the ground, a first floating capacitor between a first node between the first and second switches and a second node between the third and fourth switches, a second floating capacitor between a third node between the fifth and sixth switches and a fourth node between the seventh and eighth switches, a ninth switch between a second voltage node and a center node, a first inductor between the second node and a third voltage node, a center capacitor between the center node and the ground, a tenth switch between the second voltage node and the third voltage node, a first capacitor between the third voltage node and the ground, and a second capacitor between the second voltage node and the ground may be provided.

Abstract: Packaged electronic devices and integrated circuits include a ceramic material or other thermally conductive, electrically insulating substrate with a patterned electrically conductive feature on a first side, and an electrically conductive layer on a second side. The IC further includes a semiconductor die mounted to the substrate, the semiconductor die including an electrically conductive contact structure, and an electronic component, with an electrically insulating lamination structure enclosing the semiconductor die, the frame and the thermal transfer structure. A redistribution layer with a conductive structure is electrically connected to the electrically conductive contact structure.

Abstract: A gate driver circuit is provided that includes a high-side power transistor; a low-side power transistor coupled to the high-side power transistor, where an output voltage is generated at a load node coupled between the low-side power transistor and the high-side power transistor; a gate driver configured to receive a high-side control signal and a low-side control signal, drive the high-side power transistor based on the high-side control signal, and drive the low-side power transistor based on the low-side control signal; and a short circuit detection circuit configured to monitor for short circuit events at the high-side power transistor and at the low-side power transistor based on the high-side control signal, the low-side control signal, and the output voltage, and, generate a fault signal in response to detecting a short circuit event at either of the high-side power transistor or the low-side power transistor.

Abstract: A device includes a first amplifier and a second amplifier. The first amplifier includes an inverting input configured to be coupled to a feedback node of an output of a power converter, a first non-inverting input configured to couple to a first voltage node, a second non-inverting input, and an output. The second amplifier includes an inverting input coupled to the output of the first amplifier, a non-inverting input coupled to a second voltage node, and an output. The device also includes a first transistor coupled to the output of the first amplifier and having a control terminal coupled to the output of the second amplifier, a capacitor coupled to a ground node and to the second non-inverting input of the first amplifier, and a current node coupled to the capacitor.

Abstract: A semiconductor integrated circuit including a power switch element, a control circuit connected to the power switch element, an electrostatic discharge protection device connected to an input terminal to which an input voltage is applied, for protecting the power switch element and the control circuit from being damaged by an electrostatic discharge, and a short-to-supply fault protection circuit connected to the electrostatic discharge protection device, for protecting the power switch element and the control circuit from being damaged by a high voltage. The short-to-supply fault protection circuit includes a first step-down circuit disposed between the input terminal and the control circuit, and a second step-down circuit disposed between the input terminal and a gate of the power switch element. Each of the first and second step-down circuits, upon detecting the high voltage, steps down the high voltage for the control circuit or the power switch element.

Abstract: A power conversion device including: a power conversion unit which is connected to two DC power supplies and performs power conversion; and a control unit which calculates a manipulated variable for controlling output voltage of the power conversion unit, wherein the manipulated variable for control is calculated on the basis of a voltage detection value on the primary side or the secondary side of the power conversion unit and a predetermined fixed value.

Abstract: A semiconductor integrated circuit device includes digital output terminals and output circuits. Each output circuit includes a switch, and applies a potential, which corresponds to either one of binary logic levels, to corresponding one of the digital output terminals through the switch. An indefinite range is interposed between one of the binary logic levels and the other one of the binary logic levels. The output circuits respectively include potential fixers. Each potential fixer has an identical circuit arrangement, and the potential fixer fixes a potential applied to the digital output terminals through the switch to a potential corresponding to either one of the binary logic levels apart from the indefinite range, in response to that a short circuit occurs between the digital output terminals.

Abstract: A switch circuit includes: a power transistor having a source coupled to a supply terminal, a drain coupled to an output terminal, and a gate; a bipolar transistor having a collector coupled to the supply terminal, an emitter coupled to the gate of the power transistor, and a base; a bias circuit to control an emitter current of the bipolar transistor; and a resistor coupled between the supply terminal and the base. A control circuit receives a current at a current input to turn the bipolar transistor on responsive to a control input being in a first state, and ceases receiving the current at the current input to reduce a gate-source voltage of the power transistor responsive to the control input being in a different second state.

Abstract: Embodiments described herein provides a battery charging circuit that boosts an input current and feeds the boosted input current to a battery for fast charging. Specifically, the battery charging circuit includes a low dropout regulator (LDO) for providing a voltage, a switch mode charger, coupled between the LDO and a battery, and a capacitor divider, coupled between the LDO and the battery, in parallel to the switch mode charger, for dividing the voltage outputted from the LDO by a factor.

Abstract: A modified modulated wave acquisition method includes: obtaining a modulated wave uaba; calculating a difference between the given value iNq* and the actual value iNq of the q-axis component of a grid side current, inputting the result to a proportional integral (PI) controller, and multiplying an output of the PI controller by cos ?t to obtain a modulated wave offset ?uaba; and calculating a difference between the modulated wave uaba and the modulated wave offset ?uaba to obtain a modified modulation wave uaba?, where ?t is a grid voltage phase in a sinusoidal case. The MPC method for a single-phase cascaded H-bridge rectifier includes: obtaining the modified modulated wave uaba?, where the component iNq* is 0; and replacing the modulated wave uaba with the modified modulated wave uaba? to perform MPC for the single-phase cascaded H-bridge rectifier.

Abstract: A DC-DC converter providing adaptive peak current control is disclosed. A DC-DC converter includes an inductor having first and second terminals coupled to a voltage source and a transistor, respectively. The DC-DC circuit further includes a control circuit configured to control activation of the transistor. A first control block of the control circuit controls the transistor (and thus the inductor peak current) using pulse frequency modulation (PFM). A second control block controls the transistor using pulse width modulation (PWM) and PFM. In a first mode of operation, the control circuit activates the transistor, using PFM, such that the peak-to-peak current through the inductor has a fixed value. In a second mode of operation, the control circuit activates the transistor such that the peak-to-peak current through the inductor is modulated, using both PWM and PFM.

Abstract: The present invention discloses a gate drive circuit for reducing a reverse recovery current of a power device, and belongs to the field of basic electronic circuit technologies. The gate drive circuit includes a high-voltage LDMOS transistor, a diode forming a freewheeling path when the diode is turned on or a low-voltage MOS transistor in anti-parallel connection with a body diode, and a voltage detection circuit.

Abstract: Voltage on the output terminal of an inductor is obtained as a first input signal to a control block (CB); the inductor has an input terminal connected to a power switch and driver block at a switching node. A sense input voltage is obtained on an output terminal of a sensing circuit that is not directly connected to the switching node, as a second input signal to the CB. A voltage is generated on a first output terminal of the CB and is selected such that the CB can use its first and second input signals to infer the current through the inductor. A pulse width modulation (PWM) signal is generated on a second output terminal of the CB, based on the inferred current through the inductor; the second output signal from the CB is provided to a PWM input terminal of the power switch and driver block.

Abstract: An alternating-current (AC) voltage regulator configured to receive an input voltage. The regulator including an AC/DC pulse-width modulated (PWM) power supply configured to receive the input voltage and output a direct-current (DC) signal isolated from the input voltage. The regulator including a control circuit configured to receive a portion of the input voltage, adjust an amplitude and a phase of the portion of the input voltage, and output the adjusted voltage. The regulator including an amplifier configured to receive, via an power input, the isolated DC signal; receive, via a first input, the adjusted voltage; receive a feedback loop from an amplifier output to a second input; and output, via the amplifier output, a differential signal. The regulator including an output configured to add the differential signal to the input voltage resulting in a regulated voltage, and output the regulated voltage.

Abstract: A method and apparatus for voltage clamping including: measuring a DC voltage across the PV module at an input of a power converter, comparing the measured DC voltage to the overvoltage threshold, determining the measured DC voltage exceeds the overvoltage threshold, and operating a clamping circuit to clamp at least a portion of the DC voltage prior to input to the power converter.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed to improve performance while reading a one-time programmable memory. An example apparatus includes: a voltage boost circuit including a first output, a second output, a first input configured to be coupled to a controller, a second input coupled to a first output of a decoder, a third input coupled to a second output of the decoder; and a multiplexer including a first input coupled to the first output of the voltage boost circuit, a second input coupled to the second output of the voltage boost circuit, a third input coupled to an array of memory, and an output coupled to a sensing circuit.

Abstract: An electronic system includes a plurality of voltage regulators configured to convert an input voltage, a plurality of inductors respectively connected to the plurality of voltage regulators to respectively output a plurality of converting currents, and a switching unit configured to select at least one converting current from among the plurality of converting currents in response to a switching control signal and supply power to a load unit based on the selected at least one converting current.

Abstract: A flyback power converter includes a primary side controller circuit for controlling a primary side switch; and a secondary side controller circuit for generating an SR (Synchronous Rectification) signal to control an SR switch. The SR signal includes an SR pulse and a ZVS (Zero Voltage Switching) pulse. The SR pulse controls the SR switch for synchronous rectification at the secondary side. The secondary side controller circuit samples and holds a voltage at a first end of the SR switch as a first voltage at a timing between the end of the ZVS pulse and the beginning of the SR pulse, and determines a length of the ZVS pulse so as to control the SR switch to be conductive for a ZVS time period, whereby the primary side switch achieves ZVS. The first voltage is proportional to an input voltage.

Abstract: A voltage regulator control integrated circuit includes constituent parts including an error amplifier circuit, a comparator circuit, a compensation signal generator circuit, an oscillator/one-shot circuit, a latch, and a current sense circuit. In a first example, the integrated circuit is operable in a first mode and in a second mode. In the first mode, the various parts are configured and interconnected in such a way that they operate together as a valley current mode regulator control circuit. In the second mode, the various parts are configured and interconnected in such a way that they operate together as a current-mode constant on-time mode regulator control circuit. In another example, a voltage regulator control integrated circuit has the same basic constituent parts and is operable in a first mode as a peak current mode regulator control circuit, or in a second mode as a constant off-time time mode regulator control circuit.

Abstract: In accordance with an embodiment, a memory cell device includes at least one memory cell; a first switch connected between the at least one memory cell and a reference potential node; a second switch connected between the at least one memory cell and the reference potential node, and switch driver logic adapted to put the first switch selectively into one of at least three operating states by activation or deactivation of a first subcircuit of the switch driver logic, wherein the at least three operating states comprises an on state, an off state, and a conductive state in which an electrical conductivity of the first switch is lower than in the on state and higher than in the off state, and put the second switch selectively into one of the at least three operating states by activation or deactivation of a second subcircuit of the switch driver logic.

Abstract: A circuit includes a first voltage divider coupled between an output node and a ground voltage, and a second voltage divider coupled between the output node and a modulation node. The first voltage divider includes the modulation node. The modulation node is configured to receive a pulse width modulation (PWM) modulated control signal having an open drain configuration. The modulation node is switchable by the PWM modulated control signal between a floating state and a grounded state. The modulation node experiences a high impedance with respect to a ground connection while in the floating state and experiences a low impedance with respect to the ground connection while in the grounded state.

Abstract: A circuit and method for protecting from reverse current is disclosed. A reverse current protection circuit is coupled to a pass transistor of power circuitry (e.g., a power switch or voltage regulator), the pass transistor being coupled between first and second voltage nodes, the first voltage node being coupled to a power supply circuit. The reverse current protection circuit includes a sensing circuit that is configured to sense an amount of reverse current flowing through the pass transistor (from the second voltage node to the first voltage node). Responsive to the amount of reverse current exceeding a threshold value, the reverse current sensing circuit activates a shunt circuit, which redirects at least some of the reverse current to a reference node (e.g., ground).

Abstract: An electric switch-mode power converter comprises: a parameter predictor for predicting and updating at least one regulator parameter of a regulator controlling a switching device of the converter, a performance feedback signal generator for providing a performance feedback signal indicative of a performance of the conversion operation, wherein the parameter predictor is configured to predict an update of the regulator parameter based on the performance feedback signal and during update intervals, the intervals being during the power conversion operation and being separated by pauses without update.

Abstract: A high-voltage pulser circuit for Electromagnetic Acoustic Transducer (EMAT) coils using a Capacitive Discharge push-pull converter. The present invention relates in particular to the operation of the converter into an Electromagnetic Acoustic Transducer (EMAT) differential coil. The present invention reduces ringing of the coil current resulting in a smaller blind zone and a well-defined broadband ultrasonic wave from the coil. The pulser can be used to generate one or more cycles and work in either pulse-echo (same transmitter and receiver) or pitch-catch (different transmitter and receiver).

Abstract: A direct current voltage step-down regulation circuit structure is provided, which includes a switching circuit and a feedback regulation circuit connected to the switching circuit. An output capacitor is arranged at an output end of the switching circuit, and the switching circuit receives an input voltage at an input end thereof. The feedback regulation circuit includes a first operational amplifier, a second operational amplifier and voltage division power supplies. A non-inverting input terminal of the first operational amplifier is connected to a first voltage division circuit. A non-inverting input terminal of the second operational amplifier is connected to a second voltage division circuit. The voltage division power supplies are respectively connected to the first voltage division circuit and the second voltage division circuit.