48 results about "Parasitic oscillation" patented technology

A two-transistor flyback topology in which a portion of leakage inductance energy in the transformer is extracted and used to obtain zero voltage switching on both switching elements in any operating conditions, and in which a third low power switch eliminates parasitic oscillations and allows an operation at a determined frequency. In this topology, there are no switching losses and there are no spikes or glitches in any switching node, eliminating the need for snubbers. This topology is an “ideal two transistor flyback topology.”

A buck topology operates in discontinuous mode in which energy contained in the parasitic oscillations is harvested as needed, with additional energy provided by a voltage injection source, the power switchers of the buck topology turn on at zero voltage in any operating conditions.

An object of the present disclosure is to suppress reduction of noise resistance and parasitic oscillation in a semiconductor device. A semiconductor device includes: a plurality of semiconductor chips parallelly connected to each other; a source electrode; a first source pattern connected to the source electrode; a source sensing terminal; and a second source pattern connected to the source sensing terminal, wherein a surface of each of the semiconductor chips is connected to the first source pattern, a surface of a reference chip is connected to the second source pattern, a surface of at least one non-reference chip as the semiconductor chip other than the reference chip is not connected to the second source pattern, and a resistance value of a gate resistance of the reference chip is larger than a resistance value of a gate resistance of the non-reference chip.

The invention relates to the field of DC / DC converters, and aims to provide a synchronous rectification circuit and method applied to a bidirectional CLLC resonant converter. The synchronous rectification circuit comprises a high-speed current sampling circuit, a zero crossing point detection circuit, a timer circuit, a logic processing circuit and a driving circuit. According to the invention, the change state of the secondary side resonance current is detected, the reliable action of the switching tube is ensured according to the delay signal of the timer, and the misoperation of the switching tube possibly caused by parasitic oscillation of the circuit can be avoided. According to the method, the accuracy and reliability of synchronous rectification are improved, complex calculation is not needed, and the method has the advantages of being wide in application range and good in anti-interference performance. According to the invention, through real-time detection of the secondary side resonance current, synchronous rectification in the same period can be realized, and the conversion efficiency of the converter is improved.

The invention is a method and an analysis device for determining an oscillation pattern of a substance without using an excitation source for the substance. The analysis device comprises a central unit having two identical sample containers, two microphone apparatuses, and a differential amplifier; wherein: one of the microphone apparatuses is located in each of the sample containers; the microphone apparatuses are electronically coupled to the differential amplifier via respective connecting lines; the connecting lines are of identical design; and the differential amplifier is designed to compensate for in-phase parasitic oscillations from both sample containers and, when the substance is introduced into one of the two sample containers, to determine the oscillation pattern of the substance without using an excitation source for the substance.

The application relates to the field of DC / DC converters, and aims to provide a synchronous rectification circuit and method applied to a bidirectional CLLC resonant converter. The synchronous rectification circuit comprises a high-speed current sampling circuit, a zero-crossing point detection circuit, a timer circuit, a logic processing circuit and a driving circuit; the application detects the change state of the resonant current on the secondary side, guarantees the reliable action of the switch tube according to the delay signal of the timer, and can avoid the misoperation of the switch tube caused by the parasitic oscillation of the circuit. The application improves the accuracy and reliability of the synchronous rectification, does not need to perform complex calculation, has the characteristics of wide application range and good anti-interference performance. The application can realize the synchronous rectification in the same cycle through the real-time detection of the resonant current on the secondary side, and improves the conversion efficiency of the converter.

The invention relates to the technical field of solid laser, in particular to an active Q-switched crystal waveguide for suppressing parasitic oscillation and a laser, the crystal waveguide is of a three-layer structure and comprises a core layer, an inner cladding and an outer cladding, the material of the core layer is doped with 1at.% Yb: YAG, the material of the inner cladding is doped with 0.5 at.% Er: YAG, and the material of the outer cladding is an infrared absorption material Ge. The peak power of active Q-switching and the light-to-light conversion efficiency are improved in a manner of cutting off a parasitic oscillation path in a multi-stage manner.

The invention provides a semiconductor laser with an inclined cavity surface in a vertical plane and a manufacturing method. The semiconductor laser comprises a laminated structure; the main oscillator region, the power pre-amplifier region and the conical power amplifier region are sequentially integrated on the stacked structure in the extension direction of the axis of the waveguide optical path; the laminated structure is formed on the substrate; the substrate has a preset offset cutting angle, and the preset offset cutting angle is larger than or equal to 12 degrees and smaller than 17 degrees; wherein the semiconductor laser is provided with an output cavity surface formed by cleavage along the cleavage direction of the substrate at the output end of the conical power amplifier region, and the output cavity surface is obliquely arranged relative to the direction vertical to the axis of the waveguide light path in a vertical plane. The semiconductor laser effectively solves the technical problems of parasitic oscillation and light beam quality degradation induced by residual reflection of an output cavity surface of a monolithic integrated MOPA semiconductor laser in the prior art.

A switching power conversion apparatus includes an input voltage source, an output load, a first switch connected to a switching node, and a second switch connected to the switching node. An inductive element has a magnetizing current connected to the switching node. The inductive element delivers energy via the first and second switches from the voltage source to the load during power conversion cycles. A capacitance connected to the switching node can resonate with the inductive element during a portion of the power conversion cycles to cause a parasitic oscillation. A first clamp subcircuit is across the inductive element and contains a unidirectional auxiliary switch to trap energy from the inductive element and store it into the storage capacitor and prevent parasitic oscillation. The auxiliary switch is complementary to the first switch. A current source discharges the storage capacitor and uses the energy in the switching power conversion apparatus.

The invention discloses a converter circuit for suppressing output voltage spikes. The converter circuit comprises a transformer module, an input module, a rectification output module, a first capacitive suppression module and a second capacitive suppression module, wherein the input module is arranged on a primary winding of the transformer module; the rectification output module, the first capacitive suppression module and the second capacitive suppression module are arranged on a secondary winding of the transformer module; the first capacitive suppression module is bridged at the two ends of a first path inductor, and the first path inductor is located between the first end of the secondary winding and the first end of the rectification output module; the second capacitive suppression module is bridged at the two ends of a second path inductor, and the second path inductor is located between the second end of the secondary winding and the second end of the rectification output module; the capacitive suppression module only comprises a capacitor. According to the invention, the junction capacitance parasitic oscillation in the turn-on and turn-off processes of the rectification device in the output rectification module can be suppressed, and the output voltage spike of the output rectification module can be greatly reduced, so that the voltage stress of the output rectification module is reduced, and the circuit stability is improved.

The invention relates to the technical field of gallium nitride TVS tubes, in particular to a gallium nitride TVS tube interference suppression circuit which comprises an input driving circuit which comprises a transistor Q1, a transistor Q2, a voltage stabilizing diode Z1, a resistor R4, a resistor R2, a thermistor R3, a capacitor C2, a capacitor C3, a diode D1, an inductor L1, a power supply VCC and a primary transformer T2. A signal GT is input into one end of the Zener diode Z1, the other end of the Zener diode Z1 is connected with the resistor R4, the resistor R4 is connected with the capacitor C2 in parallel, and one end of the resistor R4 is connected with the base electrode of the transistor Q1 and the base electrode of the transistor Q2. Interference from the outside is absorbed through the TVS tube Z1 and the TVS tube Z2, the two TVS tubes are connected in a back-to-back mode, interference from an external circuit is effectively absorbed, meanwhile, interference from a transformer is also absorbed, in addition, parasitic oscillation of the driving circuit is attenuated through the capacitive characteristic of the two TVS tubes, work abnormity of gallium nitride is avoided, and the driving circuit is safe and reliable. The stability of the whole circuit is improved.

The invention relates to the technical field of gate drive circuits, and provides a crosstalk parasitic oscillation suppression method and circuit, a test platform and equipment, and the method comprises the steps: a drive signal generation module generates a gate drive signal, and the gate drive signal is transmitted to a gate of a main MOS tube through a module in which an auxiliary MOS tube and an auxiliary capacitor are connected in parallel; when crosstalk parasitic oscillation is generated, the auxiliary capacitor and the parasitic inductor of the circuit form series resonance so as to form a low-impedance path for suppressing the crosstalk parasitic oscillation. When crosstalk parasitic oscillation is generated, the auxiliary capacitor and the parasitic inductor of the circuit form series resonance, and the auxiliary capacitor provides a low-impedance path for the oscillation component of the crosstalk parasitic oscillation near the resonant frequency, so that the amplitude of the crosstalk parasitic oscillation is reduced, and the influence of the crosstalk parasitic oscillation is suppressed. According to the invention, the switching speed of the main MOS tube is guaranteed without depending on complex logic control, and crosstalk parasitic oscillation can be effectively suppressed in a scene with a large voltage change rate.

The invention relates to the field of microwave vacuum electronic amplification devices, and particularly provides a double-staggered coupled cavity expansion interaction klystron with a trapezoidal sub-wavelength hole high-frequency structure, which comprises an input cavity, a plurality of middle cavities, an output cavity, a rectangular electron beam channel and a drift tube, and is characterized in that the input cavity, the plurality of middle cavities and the output cavity are sequentially connected through the drift tube; the input cavity, the middle cavity and the output cavity all adopt a double-staggered coupled cavity structure; on the basis, in the input cavity, the middle cavity and the output cavity, the resonant cavities are connected with the upper coupling cavity and the lower coupling cavity through the isosceles trapezoid sub-wavelength holes, and the long bottom edges of the isosceles trapezoid sub-wavelength holes and the wide edges of the resonant cavities are arranged in equal proportion, so that the electric field energy is more gathered in an electron beam channel, the characteristic impedance is increased, and the interaction efficiency is improved; meanwhile, the quality factor is reduced, and parasitic oscillation is avoided. Compared with an existing structure, the expansion interaction klystron has obvious advantages in the aspects of high power, high gain, high efficiency and wide bandwidth.

The disclosed embodiment provides a method and a corresponding device for avoiding parasitic oscillation in a parallel semiconductor switch. The method according to the disclosed embodiment includes: setting an unbalanced driving impedance for a plurality of parallel power devices so that only one power device controls the on transition of the switch and only one power device controls the off transition of the switch. According to the disclosed embodiment, parasitic oscillation during switch conversion is avoided, impedance matching is not required, and the impact on switching characteristics is small.

The invention discloses a pre-cavity electron beam channel structure for suppressing parasitic oscillation of a high-power gyrotron. The structure comprises a cathode end electron beam channel cylinder and a resonant cavity end electron beam channel cylinder which are communicated with each other, the cathode end electron beam channel cylinder comprises a cathode end outer cylinder and a cathode end inner cylinder which are sleeved and fixed together, and a first channel in a conical cylinder shape is formed in the cathode end outer cylinder; the resonant cavity end electron beam channel cylinder comprises a resonant cavity end outer cylinder and a resonant cavity end inner cylinder which are sleeved and fixed together, a second channel of a kidney-shaped cylindrical structure is formed in the resonant cavity end inner cylinder, the inner diameter of the second channel is gradually reduced from the two ends to the middle, and the interior of the resonant cavity end inner cylinder is further concaved inwards to form a plurality of inner holes which are not symmetric about the central axis. When the structure is used, the problems that in the prior art, a gyrotron parasitic oscillation suppression mode is complex in machining and high in cost, and parasitic oscillation of a low-frequency band cannot be effectively suppressed are solved.

The present invention discloses a waveguide energy transmission window capable of suppressing spurious mode oscillation and a manufacturing method thereof. The waveguide energy transmission window includes: a first rectangular waveguide section, a second rectangular waveguide section coaxially arranged therewith, and a circular waveguide section located therebetween, as well as a circular ceramic sheet hermetically arranged in the circular waveguide section. The long sides of the first rectangular waveguide section and the second rectangular waveguide section are parallel. A linear conductor is formed on the circular ceramic sheet along the diameter, and the linear conductor is arranged parallel to the long side of the rectangular waveguide section. The technical solution of the present invention enables the microwave axially passing through the circular waveguide section to be converted from the circular waveguide into two semi-circular waveguides for propagation, so that the electric field direction of the microwave in the circular waveguide is perpendicular to the waveguide wall direction, thereby suppressing the coexisting mode generated during the conversion of the microwave in waveguides of different shapes, and further suppressing the spurious parasitic oscillation of the microwave generated during this process; at the same time, the energy loss of the microwave when passing through the circular energy transmission window is greatly reduced, and the energy transmission efficiency is improved.

This invention discloses a low-noise, stable acquisition and amplification circuit for weak photoelectric signals. The circuit includes: a photodetector module, a transimpedance amplifier module, a power frequency notch filter and low-pass active filter module, an output buffer conditioning module, and a regulated power supply module. The photodetector module reduces the influence of junction capacitance and suppresses parasitic oscillations through parasitic suppression capacitors. The transimpedance amplifier module achieves low-noise current-to-voltage conversion of weak photocurrent. The power frequency notch filter and low-pass active filter module filters out 50Hz power frequency interference and high-frequency thermal noise. The output buffer conditioning module achieves impedance matching to ensure distortion-free signal output. The regulated power supply module provides low-ripple positive and negative power supplies and a precise reference voltage through positive voltage regulators, negative voltage regulators, and a voltage reference source, effectively suppressing power supply noise and DC drift. This invention improves the signal-to-noise ratio and acquisition stability of weak optical signals through precise port connections and coordinated operation of each module.

Methods and circuits for detecting and controlling for parasitic oscillations in a crystal oscillator circuit. An example method comprises initializing (710) power-up of the crystal oscillator circuit, wherein said initializing (710) power-up comprises increasing an effective transconductance of the crystal oscillator circuitry over time, at a first rate, and detecting (720) a frequency of oscillation of the crystal oscillator circuit. This example method further comprises, in response to determining that the detected frequency of oscillation is lower than a target frequency, restarting (730) power-up of the crystal oscillator, wherein said restarting power-up comprises increasing the effective transconductance of the crystal oscillator circuitry over time at a second rate that is slower than the first rate.

Provided is a laser device with which the occurrence of parasitic oscillation can be suppressed. A laser device 1 comprises: a light generation unit 10 that supplies excitation light Q1 from an excitation light source 12 to an inner cladding 152 of an amplification optical fiber 15 to generate seed signal light S1; and an optical amplification unit 20 that supplies the seed signal light S1 to a core 211 of an amplification optical fiber 21 and supplies excitation light Q2 from an excitation light source 22 to an inner cladding 212, thereby amplifying the seed signal light S1 to generate amplified signal light S2. The laser device 1 includes: a photodetector 71 capable of detecting a light quantity PMO of the seed signal light S1; a photodetector 72 capable of detecting a light quantity PPA of the amplified signal light S2; and a control unit 40 that controls the excitation light sources 12, 22 so that a ratio PMO / PPA is equal to or greater than a threshold α when the amplified signal light S2 is being emitted from a light emission unit 30.

The invention discloses a SiC MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) phase-shifted full-bridge topology circuit and a control method, belongs to the technical field of phase-shifted full-bridge topology circuits, and provides a SiC MOSFET phase-shifted full-bridge topology of which the secondary side adopts an active absorption circuit. The invention provides a method for solving the problem of mis-turn-off caused by interlayer capacitance interference of SiC MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) phase-shifted full-bridge topology under a no-load condition. The invention provides an active absorption circuit for solving the parasitic oscillation problem of a secondary rectifier diode, which can absorb oscillation voltage and feed back energy in an absorption capacitor to a load at the same time, and basically does not generate extra loss.

This invention discloses a method for stabilizing and correcting radio frequency power amplifiers based on modulator parasitic control, belonging to the field of radio frequency technology. The method includes: Step S1: collecting modulator output voltage, power amplifier power supply current, power amplifier power supply voltage, and gate bias voltage; Step S2: calculating parasitic response parameters using a recursive parameter algorithm and recording abnormal oscillation components; Step S3: calculating stability margin values ​​and identifying abnormal oscillation branches; Step S4: calculating the damping coefficient of the abnormal oscillation branches, constructing a digital compensator to perform a cyclic correction process, completing the cyclic correction process when the stability margin value of the abnormal oscillation branch exceeds a preset margin threshold. This invention, by collecting power amplifier power supply voltage and gate bias voltage, uses a recursive parameter algorithm to calculate parasitic response parameters in real time, and actively predicts and corrects parasitic oscillations. It has the advantage of verifying parasitic oscillations in the bias network and helps to quickly locate design defects in the bias network.

To provide a semiconductor device capable of reducing parasitic oscillation caused by inductance generated between semiconductor chips.SOLUTION: The first gate pattern 4 and the first source pattern 6 are linearly formed in parallel with each other along a first side of the insulating substrate 1. The second gate pattern 5 extends from a first side of the insulating substrate 1 to a second side opposite to the first side and is formed in a rectangular shape in a top view. The drain pattern 8 is formed so as to surround at least three sides of the square shape of the second gate pattern 5. The second source pattern 7 is formed along sides other than the first side of the insulating substrate 1 so as to surround the drain pattern 8. The first and second groups of semiconductor chips 1112 and are arranged at positions adjacent to the second source pattern 7. The first and second groups of semiconductor chips 1112 and and the second source pattern 7 are connected via a plurality of first source wires 23.SELECTED DRAWING: Figure 2

The utility model relates to a circuit for eliminating IGBT short circuit oscillation. The circuit comprises a resistor R1, a resistor R3, a resistor R2, a resistor R4, a first transistor Q3, a second transistor Q5, a first capacitor C3 and a second capacitor C4. The grid electrode of the first transistor Q3 is connected in series with the resistor R1, the resistor R2 and the first capacitor C3 are connected in series between the grid electrode and the emitter electrode of the first transistor Q3, the emitter electrode of the first transistor Q3 is connected with the grid electrode of the second transistor Q5, and the grid electrode of the second transistor Q5 is connected in series with the resistor R3. The resistor R4 and the first capacitor C4 are connected in series and arranged between the grid electrode and the emitter electrode of the second transistor Q5, and the resistor R2 and the resistor R4 which are connected in series are additionally arranged, so that the IGBT can be normally and stably started, and meanwhile, parasitic oscillation of the IGBT during short circuit can be restrained. The same function of a complex circuit can be realized by setting the resistor, the circuit cost is reduced, and the stability of the IGBT is improved.

The application provides a millimeter wave power divider based on an electromagnetic bandgap structure and belongs to the technical field of millimeter waves.The millimeter wave power divider comprises a dielectric substrate, a power divider body composed of a substrate integrated waveguide input power division stage and a half-mode substrate integrated waveguide output power division stage arranged on the dielectric substrate, a metal packaging cavity, a periodic metal column array electromagnetic bandgap resonance suppression structure arranged on the inner surface of the top cover plate of the metal packaging cavity, and a suspended microstrip line transition structure connected to the input port and the output port respectively.The application utilizes the bandgap characteristics of the electromagnetic bandgap structure to suppress the parallel plate waveguide mode excited by the deep cavity packaging, eliminates parasitic oscillation, and realizes low-loss signal transition by using the suspended microstrip line, thereby improving the transmission performance of the power divider while keeping the miniaturization advantage.

A synchronous rectification control circuit is disclosed, including a first trigger, a first comparator, a second comparator and a delay circuit, wherein the first comparator compares the drain-source voltage of the synchronous rectifier tube with a first reference signal and provides a first control signal, the second comparator compares the drain-source voltage of the synchronous rectifier tube with a second reference signal and provides a third control signal to the second input terminal of the first trigger, and the delay circuit delays the first control signal and provides a second control signal to the first input terminal of the first trigger. The delay time of the delay circuit of the synchronous rectification control circuit of the present invention is a threshold value for judging whether the body diode of the rectifier tube is normally turned on or parasitic oscillation turned on, that is, judging whether the effective start time of the third control signal is before or after the effective start time of the second control signal, respectively corresponding to the first trigger being set to two output states before maintaining the original output state, and controlling the timely conduction and shutdown of the synchronous rectifier tube.

The invention provides a low-power-consumption numerically-controlled oscillator, relates to the technical field of integrated circuits, and comprises a resonant cavity module used for generating a high-frequency resonant signal based on a resonator; the input end of the complementary cross-coupled oscillation module is connected with the resonant cavity module, and the complementary cross-coupled oscillation module is used for receiving high-frequency resonant signals and generating continuous oscillation; a capacitor array of the segmented numerical control capacitor tuning module is connected in parallel to two ends of the resonant cavity module and is used for receiving external numerical control signals and changing equivalent capacitance of a resonant network, so that wide-range and high-precision digital tuning is carried out on oscillation frequency; the parasitic oscillation suppression module is integrated in an internal feedback path of the complementary cross-coupled oscillation module and is used for suppressing direct-current positive feedback and attenuating low-frequency loop gain so as to eliminate direct-current locking and low-frequency parasitic oscillation; the input end of the output buffer module is connected with the output node of the complementary cross-coupling oscillation module, and the output buffer module is used for shaping and driving the oscillation signal and then outputting the signal. In the mode, wide tuning, ultra-low power consumption, high stability and high-precision tuning are realized, meanwhile, the phase noise performance and the mass production feasibility are improved, and the strict requirements of the battery-free Internet of Things node are met.

A method is disclosed for preventing a driver from changing the state of an output switch in response to parasitic oscillation that includes allowing or preventing a signal from the driver from reaching the output switch based on a timing signal. Also disclosed is a way to prevent a driver from changing the state of an output switch in response to parasitic oscillation by using a directional element, a timing element, and a control element. An exemplary oscillator circuit that uses a diode, a MOSFET, and a resistor to prevent parasitic oscillation without adding propagation delay, and a block diagram of circuit functionality, is also disclosed.

The invention relates to the field of integrated circuits, in particular to a low-phase-noise differential oscillator, a self-adaptive biasing circuit and application of the low-phase-noise differential oscillator and the self-adaptive biasing circuit. The oscillator adopts a Class-C architecture, and a self-adaptive bias circuit composed of two bias copy transistors, an integrating capacitor and a bias resistor is introduced. The self-adaptive biasing circuit and the Class-C oscillator can form a feedback loop, so that the differential crystal oscillator can reliably start oscillation in a C-type working mode; and the conduction angle of the cross coupling pair is limited in a relatively small range, so that extra noise is prevented from being introduced by an overlarge conduction angle. The adaptive biasing circuit can further reduce the pole frequency corresponding to a low-frequency additional resonance point introduced by the Class-C structure. Therefore, the problem that the differential crystal oscillator is difficult to give consideration to reliable oscillation starting and parasitic oscillation suppression is solved.

The utility model discloses a half-bridge LLC resonant circuit, a power panel and a display device. The half-bridge LLC resonant circuit comprises a half-bridge LLC topology module, a first capacitor, a second capacitor and a multiplexing resistor unit. The first capacitor and the second capacitor are connected in series to form an energy storage string, one end of the energy storage string is connected with the first end of the first switch unit, and the other end is connected with the second end of the second switch unit; one end of the multiplexing resistor unit is connected with a first series node, the other end is connected with a second series node, the first series node is a connection node of the first capacitor and the second capacitor, and the second series node is a connection node of the first switch unit and the second switch unit. The first capacitor and the second capacitor are connected in series and then are connected in parallel with the first switch unit and the second switch unit which are connected in series, a feedback path of high-frequency noise generated by the half-bridge LLC topology module at the switch node and high-frequency parasitic oscillation in the circuit is formed, the noise can quickly return to the source, and it is ensured that the noise path is controllable.

This invention provides an all-solid-state high-power single-frequency laser based on a fiber-slab hybrid structure, belonging to the field of solid-state laser technology. It includes an all-solid-state continuous single-frequency seed module, a fiber pulse modulation module, a fiber pre-amplification module, a slab laser pre-amplification module, a slab laser main amplification module, and a frequency doubling module, arranged sequentially. Both the slab laser pre-amplifier and the slab laser main amplifier in this invention utilize a multi-pass amplification designed with the principle of spherical aberration self-compensation to compensate for thermal aberrations generated by the slab laser, thereby improving beam quality. Furthermore, this invention uses discrete mirror groups instead of complete amplifier cavity mirrors, effectively suppressing spontaneous emission and parasitic oscillations during amplifier operation, resulting in a single-frequency pulsed laser with excellent beam quality in the near-hundred mJ range, which can meet the requirements for lidar detection or industrial applications.