96 results about "Pulse-frequency modulation" patented technology

The present disclosure provides an approach that determines a pulse frequency modulation (PFM) period of a buck regulator. The PFM period comprises a first charging stage and a first discharging stage, and wherein the buck regulator switches from the first discharging stage to the first charging stage based on comparing a feedback voltage to a low threshold voltage. The approach generates a pseudo random pulse at a pseudo random period, wherein the pseudo random period is independent from the low threshold voltage. Then, the approach initiates a transition from a second discharging stage to a second charging stage based on the pseudo random pulse.

The invention provides an infrared image sensor and a pixel-level reading circuit thereof, and relates to the field of infrared image sensors. The pixel-level reading circuit is integrated in a single pixel unit, and comprises a direct injection input-level circuit used for converting an infrared light-generated current generated by an infrared image sensor into an analog voltage signal; the pulse frequency modulation analog-to-digital converter is connected with the direct injection input stage circuit and is used for converting the analog voltage signal into a pulse signal; the SR latch is electrically connected with the pulse frequency modulation analog-to-digital converter and is used for carrying out accumulative counting on the pulse signals so as to form digital code words reflecting the infrared light intensity; and the digital logic control unit is electrically connected with the SR latch and is used for transmitting the digital code word to a reading bus of the infrared image sensor, so that the output of a digital signal is realized, and the reading rate of the image sensor is improved.

The invention discloses an air pressure sensor communication control method and system based on PFM pulse frequency modulation, in a multi-sensor networking scene, environmental parameters are converted into analog electric signals through signal conditioning and then mapped into a unique pulse change sequence, and coding optimization is carried out for the matching degree of the pulse sequence and the parameter variable quantity. High-fidelity and low-power-consumption data expression and transmission are realized; anti-interference filtering is implemented through a communication link in combination with a signal transmission protocol, and original parameter data is restored through inverse mapping after the integrity of a pulse sequence is ensured; then, the data of the multi-source sensor is integrated in the main control unit to form a networking parameter data set, abnormal deviation is judged through comparison logic, a control instruction is generated and fed back to a terminal to execute accurate adjustment, a complete link from sensing and optimized transmission to closed-loop regulation and control is formed, and finally high-reliability real-time monitoring and self-adaptive intelligent regulation and control of environmental parameters are achieved.

According to the light-load current limiting circuit of the switching circuit provided by the embodiment of the invention, the voltage and current conversion module generates the initial error current and the pulse frequency modulation current according to the fixed voltage when the clamping module locks the error voltage to the fixed voltage; the clamping module is used for locking the error voltage received by the voltage-current conversion module to a fixed voltage when the error current is smaller than the first reference current; the trigger signal generation module is used for generating a first trigger signal at a first preset moment and generating a second trigger signal at a second preset moment when the clamping module locks the error voltage received by the voltage and current conversion module to a pulse signal period corresponding to the fixed voltage; and the switch module is connected in a first mode when receiving the first trigger signal and determines a target voltage input to the pulse width modulation module, and the switch module is connected in a second mode when receiving the second trigger signal and the second resistor is connected to an output load of the switch circuit through the switch module.

The invention discloses a humanoid robot control method based on a neural circuit, and belongs to the technical field of robot control, and the method comprises the steps: S1, constructing a three-layer pulse neural control architecture comprising spinal cord reflex, brainstem balance and cortex decision, and carrying out the weight adaptive distribution and cooperative operation between layers through the dynamic adjustment of neurotransmitter concentration, organic cooperation of prediction and reflection is realized through a three-stage control system; the cerebellar prediction network executes attitude adjustment in advance through a delay compensation algorithm, and compared with pure feedback, the control energy consumption is reduced; the parallel reflex pathway of the spinal cord layer establishes a nerve bypass mechanism, and the emergency response is realized by bypassing high-level processing in an emergency; the multi-layer safety monitoring improves the triggering accuracy of a protection mechanism through error confidence evaluation and contact stability analysis; a weight transfer mechanism of pulse frequency modulation avoids sudden movement change during control mode switching; by means of the design, the stability retention rate of the robot walking on the inclined plane is remarkably improved compared with a traditional method.

The invention provides a driving system and method for a vehicle-mounted lamp and a vehicle, and relates to the technical field of vehicle lamps, and the driving system comprises a single-end primary inductance converter and a control module; the single-end primary inductance converter comprises a power supply module and a gallium nitride switch module, and the gallium nitride switch module is connected with the power supply module and the vehicle-mounted lamp; the control module is connected with the gallium nitride switch module and the vehicle-mounted lamp, the control module is used for detecting the load current of the vehicle-mounted lamp and switching the on-off state of the gallium nitride switch module and the working mode of the driving system based on the load current, and the working mode comprises a pulse width modulation mode, a pulse frequency modulation mode and a burst mode. The system is provided with the gallium nitride switch module, so that the synchronous rectification effect can be achieved, and the conduction loss and the switching loss are relatively low. And secondly, the system adopts a hybrid modulation strategy, so that the optimal working mode can be automatically switched in different load states, and the driving stability, reliability and efficiency of the system are improved.

A switching converter controller includes: a stopband controller having a stopband controller input and a stopband controller output, the stopband controller is configured to provide stopband information at the stopband controller output responsive to a reference signal; a pulse-frequency modulation (PFM) controller having a first PFM controller input, a second PFM controller input and a PFM controller output, the first PFM controller input configured to receive a feedback error signal, the second PFM controller input coupled to the stopband controller output, and the PFM controller configured to selectively adjust a clock signal at the PFM controller output based on the feedback error signal and the stopband information; and a driver circuit having a driver circuit input coupled to the PFM controller output and configured to receive the clock signal, and having a driver circuit output adapted to be coupled to a power stage switch.

The invention discloses a DCAC power conversion device and a power conversion method thereof, and the device comprises a full-bridge inverter which is used for converting an input DC voltage into a high-frequency AC voltage; the LCL resonance network is connected to the output end of the full-bridge inverter and is used for being equivalent to a current source in a target frequency range to realize zero voltage switching ZVS and harmonic suppression; the primary side of the high-frequency isolation transformer is connected with the LCL resonance network, and the secondary side of the high-frequency isolation transformer is connected with a load to realize electrical isolation of input and output; and the load phase angle detection module is used for detecting current and voltage signals of a load in real time, calculating a load phase angle # imgabs0 # hybrid control unit and dynamically switching control modes according to the numerical relationship between the load phase angle # imgabs1 # and a preset threshold # imgabs2 # so as to control the output current, and the control modes comprise pulse frequency modulation (PFM) and phase shift pulse width modulation (PS-PWM). According to the device and the method, through the cooperative operation of the LCL resonance network and the hybrid control unit, the problems of large switching loss, low constant current precision and difficulty in EMI suppression in high-frequency application are solved.

A switching converter controller includes: mode control logic; and a pulse-frequency modulation (PFM) timer circuit coupled to the mode control logic. The PFM timer circuit includes: a first terminal; a second terminal; a digital-to-analog converter (DAC); a current source; a capacitor; and a comparator. A first terminal of the DAC is coupled to the first terminal of the PFM timer circuit. The current source has a first terminal, a second terminal, and a third terminal. The second terminal of the current source is coupled to a second terminal of the DAC. A first terminal of the capacitor is coupled to the first terminal of the current source. The comparator has first, second, and third terminals. The first terminal of the comparator is coupled to the first terminal of the capacitor. The third terminal of the comparator is coupled to the second terminal of the PFM timer circuit.

The invention relates to a buck switched mode power supply. A buck-type switched mode power supply includes a switching unit formed of a first switch configured to be periodically set to an on state by a first control signal modulated by a pulse width or pulse frequency modulation type. The amplifier generates an error voltage representing a difference between a reference voltage and an output voltage of a power supply intended to be applied to an input of the amplifier. The delay circuit applies a delay to the first control signal to reduce a difference between the error voltage and the reference voltage. The delay modulation circuit modulates a value of the delay according to a difference between the error voltage and a reference voltage.

The invention discloses a wide-input single-stage Boost-LLC converter and a control method thereof, and relates to the field of power factor correction AC-DC converters. According to the wide-input single-stage Boost-LLC converter, a pulse frequency and pulse width hybrid modulation mode is introduced on the basis of basic pulse frequency modulation control, the voltage stress of a switching device can be reduced, and the input voltage range can be expanded; by introducing quasi-resonance control, the problem that the output of the single-stage AC-DC converter is seriously influenced by double power frequency ripples is solved, and the condition that the output voltage of the secondary side is unstable when the switching frequency is too low is suppressed by adopting a CLC filtering mode at the secondary side. The single-stage Boost-LLC converter has the beneficial effects that through a hybrid modulation mode, the single-stage Boost-LLC converter can realize wide-range input under the condition that the voltage stress requirement of a switching device is not high, double power frequency ripples on the output side are effectively reduced, the stability of the output voltage is ensured, only one-stage power conversion exists in a system, and the system is simple in structure and low in cost. The device has the advantages of small size, high efficiency and low cost.

A power conversion circuit includes a transformer, a resonant capacitor, a resonant inductor, a high-side transistor, a low-side transistor, and a control circuit. The transformer includes a primary coil and a secondary coil. The primary coil, the resonant capacitor, and the resonant inductor are connected in series between a switch node and a ground. The high-side transistor provides an input voltage to a switch node based on the high-side driving signal. The low-side transistor couples the switch node to the ground based on the low-side transistor. The control circuit operates in a pulse frequency modulation mode to generate the high-side transistor and the low-side transistor with a switch frequency. When the switch frequency exceeds the first threshold, the control circuit switches from the pulse frequency modulation mode to the pulse width modulation mode.

The invention discloses a power conversion circuit and a control method thereof. The power conversion circuit comprises a transformer, a resonant capacitor, a resonant inductor, an upper bridge transistor, a lower bridge transistor and a control circuit. The transformer comprises a primary coil and a secondary coil. The primary coil, the resonant capacitor and the resonant inductor are connected in series between the switching node and the ground terminal. The upper bridge transistor supplies an input voltage to the switching node based on an upper bridge driving signal. The lower bridge transistor couples the switching node to a ground terminal based on a lower bridge driving signal. The control circuit is operated in a pulse frequency modulation mode to generate an upper bridge driving signal and a lower bridge driving signal at a switching frequency. When the switching frequency exceeds a first threshold value, the control circuit switches from the pulse frequency modulation mode to the pulse width modulation mode.

This invention discloses a method and system for resisting slice reconstruction interference based on alternating frequency modulation slope polarity and time-series agility. It mainly addresses the problems of high complexity, poor real-time performance, and high dependence on prior information and training data in existing technologies. The scheme is as follows: At the transmitting end, a joint agile transmission signal is established based on the number of sub-pulses, sub-pulse duration, sub-pulse interval, sub-pulse bandwidth, and sub-pulse frequency modulation slope; at the receiving end, the received signal is segmented according to the recorded sub-pulse timing to obtain each segment signal, and pulse compression and delay compensation for both matched and mismatched channels are performed simultaneously; dynamic weights are generated based on the energy of the two compensated channels; an anomaly suppression factor is constructed based on the energy of the matched channels of each segment, and the output of each segment's matched channels is weighted and accumulated using this factor and the dynamic weights to obtain a one-dimensional range profile result. This invention does not require a large amount of training data or estimation of interference parameters, has low computational complexity, can suppress false targets generated by slice reconstruction interference while maintaining the energy of the real target, and can be used for target detection.

The present disclosure relates to multiphase switching voltage regulators and controllers. A controller for a multiphase switching voltage regulator includes a first control loop and a second control loop. The first control loop has a first set of coefficients for implementing pulse width modulation (PWM) and a second set of coefficients for implementing pulse frequency modulation (PFM). The second control loop is configured to implement phase current balancing for the multiphase switching voltage regulator. In a first configuration, the first control loop is configured to implement PWM-based control of the multiphase switching voltage regulator using the first set of coefficients. In a second configuration, the first control loop is configured to implement PFM-based control of the multiphase switching voltage regulator using the second set of coefficients.

The invention provides a soft switching implementation and synchronous hybrid control method for a bidirectional symmetric CLLLC resonant converter, which relates to the technical field of converter control and comprises three steps of constructing a bidirectional symmetric network and setting soft switching conditions, executing synchronous hybrid control and monitoring the state of the soft switching. According to the invention, the CLLLC resonant network is constructed by adopting the design that the parameters of the primary side and the secondary side are symmetrical, the symmetrical soft switching control can be realized when the converter is in the forward and reverse working modes, the stability and the symmetry of the system are improved, and the stability and the symmetry of the system are improved by optimizing the soft switching condition and combining the two control modes of pulse frequency modulation and pulse width modulation. The working state of the system can be automatically adjusted within the wide input / output voltage and load change range, soft switching is kept all the time, and therefore the problems that in a traditional method, due to input voltage fluctuation and load change, system efficiency is reduced, and stability is poor are solved.

The embodiment of the invention provides a voltage drop circuit and a charging controller and method for the voltage drop circuit, and the charging controller compares a reference voltage with a plurality of feedback voltages of a plurality of output voltages which are output to a plurality of voltage output ends by a pulse frequency modulation voltage drop module through a single inductor and a plurality of change-over switches. Each of the plurality of change-over switches is disposed between a single inductor and a corresponding voltage output terminal. Then, the charging controller determines the charging sequence of the plurality of voltage output ends according to the plurality of comparison result signals. And the control module is used for generating a plurality of switching signals for controlling the plurality of change-over switches and a starting signal for enabling the pulse wave frequency modulation voltage drop module to charge one of the plurality of voltage output ends according to the zero current detection signal of the single inductor and the charging sequence.

The present disclosure provides a method of determining a pulse frequency modulation (PFM) period of a buck regulator. The PFM period comprises a first charging phase and a first discharging phase, and wherein the buck regulator switches from the first discharging phase to the first charging phase based on comparing a feedback voltage to a low threshold voltage. The method generates a pseudo-random pulse at a pseudo-random period, where the pseudo-random period is independent of the low threshold voltage. The method then initiates a transition from a second discharge phase to a second charge phase based on the pseudo-random pulse.

A system may include a power converter comprising a power inductor and a plurality of switches and a controller configured to control the power converter, including controlling the power converter in discontinuous conduction mode to magnetize and demagnetize the power inductor, wherein the controller is further configured to, in each switching cycle of the power converter, terminate a magnetization period of the power inductor based on a function dependent upon an output voltage of the power converter and a power inductor current flowing through the power inductor.

The present application discloses a control circuit, a control method, a power conversion circuit and an electronic device, relating to the technical field of electronic circuits. The control circuit outputs a first pulse width modulation signal and a second pulse width modulation signal for controlling a switched-capacitor converter. The control circuit includes a signal generation module and a signal setting module. The signal generation module outputs a first indication signal when the output voltage drops to a first preset voltage, and outputs a second indication signal when the output voltage rises to a second preset voltage. When the switched-capacitor converter is in the charge pump operating mode, the signal setting module sets the first pulse width modulation signal and the second pulse width modulation signal to signals with a duty cycle of 50%. When the switched-capacitor converter is in the pulse frequency modulation operating mode, if the first indication signal is received, the first pulse width modulation signal is set to a high level, and if the second indication signal is received, the second pulse width modulation signal is set to a high level. By the above method, the voltage conversion efficiency can be improved.

A universal serial bus power transfer power adapter and a method of operating the same are disclosed. In an embodiment of the technology presented herein, a universal serial bus power transfer (USB-PD) power adapter includes: a USB port; and a USB controller configured to transmit power to the USB port, where the USB controller includes: a voltage regulator configured to generate a supply voltage based on a pulse frequency modulation (PFM) signal; and a variable current bleeder unit configured to generate a variable current bleeder load on the voltage regulator based on the frequency of the PFM signal to maintain the frequency of the PFM signal above an audible frequency range.

A tool storage system is provided that includes a drawer, and an optical system configured to detect presence of an object in the drawer. The optical system includes a photoelectric sensor and processing circuitry. The photoelectric sensor includes a light transmitter configured to emit pulsed light, and a photoelectric receiver configured to convert a reflection of the pulsed light off of the object to an electrical signal that indicates proximity of the object and thereby the presence of the object in the drawer. The processing circuitry is configured to output a pulse-frequency modulation (PFM) signal from which the light transmitter is driven to emit the pulsed light. The PFM signal has a frequency that is adjustable to control an average intensity of the pulsed light, the frequency calibrated for a type of the object and an effective range of the photoelectric sensor.

The application provides an adaptive optimization charging method for a LCC resonant converter with a capacitive load based on an improved fundamental equivalent model, to solve the long charging time, large frequency variation range, narrow ZVS range and other defects of a traditional CC charging method. The charging method comprises the following steps: establishing an enhanced fundamental approximation (E-FHA) model; obtaining an analytical expression of a voltage gain M, a resonant current effective value I rms , an average output current I o and a switching frequency f s ; determining the relationship between the maximum average output current and the switching frequency during charging directly through the analytical expression and an AOC method, and realizing a pulse frequency modulation (PFM) frequency control curve. The method provided by the application fully utilizes the working current limit of the switch and the switching frequency limit to obtain a higher average output current, thereby improving the charging speed and reducing the switching frequency range and temperature rise.

The invention provides a soft switching three-level boost converter topological structure and a working method thereof. The topological structure comprises a direct-current power supply, a resonant structure and an output circuit structure which are connected in sequence, the resonant structure comprises a switching tube S1, a switching tube S2, a diode D1, a diode D2, a diode D3, a diode D4, a resonant inductor Lr and a resonant capacitor Cr, and zero-current switching-on of the power switching device is realized through combination of the resonant inductor Lr, the resonant capacitor Cr and other elements. And the switching loss is effectively reduced. High-frequency loss is avoided by combining pulse frequency modulation of the CRM mode and the DCM mode. According to the topology, zero-current switching-on of the switching tubes, reduction of the inductor size and improvement of the overall efficiency are achieved, and the topology is suitable for various working conditions such as high gain and low gain.

This invention discloses an LLC resonant converter with a wide output voltage range based on a voltage doubler rectifier, applicable to DC fast charging of new energy vehicles. The converter achieves primary-side inversion and secondary-side rectification topology reconfiguration through switch drive signals, enabling wide-range voltage output in four operating modes. The primary side can switch between half-bridge and full-bridge inversion modes, while the secondary side can switch between full-bridge, voltage doubler, and voltage quadruple rectifier modes. This invention reduces diode voltage stress, possesses self-balancing capability of the voltage doubler capacitor, and achieves soft switching across the entire voltage range. Ultra-wide voltage gain is achieved within a narrow frequency adjustment range across the entire voltage range through simple pulse frequency modulation (PFM), allowing the converter to adapt to the charging needs of new energy vehicles with different voltage platforms.

A DC-DC converter operating in pulse frequency modulation (PFM) and pulse width modulation (PWM) modes includes a plurality of PWM signal generators. The PWM signal generators generate PWM signals with different duty cycles. PWM signals with larger duty cycles may be selected for use in undervoltage situations. The DC-DC converter may include gain circuitry coupled as feedback from the output to the PWM signal generators to provide alternating current (AC) regulation.

The application discloses a control circuit, a control method and a resonant converter compatible with LLC and DCX, the control circuit comprises: a reference voltage generation circuit, which is used for generating a corresponding pulse width modulation reference voltage according to a selected control mode; a modulation signal generation circuit, which is used for comparing a slope voltage with the pulse width modulation reference voltage to output a pulse width modulation signal, and comparing the slope voltage with a correlation voltage of the pulse width modulation reference voltage to output a pulse frequency modulation signal; the correlation voltage comprises at least one voltage used for generating the pulse width modulation reference voltage; and a logic control circuit, which is used for generating an upper tube driving signal and a lower tube driving signal according to the pulse width modulation signal and the pulse frequency modulation signal. The application can configure the resonant converter to work in the DCX mode or the LLC mode according to different scenes, and reduces the design complexity and cost of the resonant converter system.

The utility model discloses a load detection circuit which is used for detecting the connection state of a load in a charging and discharging circuit. The load detection circuit includes a switching element, a first resistor, and a controller. The input end of the switch element is connected with the power supply, and the output end is connected with the controller. The input end of the first resistor is connected with the first output end of the switch element, and the output end of the first resistor is connected with the common end of the DC-DC converter switch pin and the energy storage element in the charging and discharging circuit. The direct current-direct current converter comprises a pulse frequency modulation working mode, in the pulse frequency modulation working mode, the common end transmits a low level signal to the first output end of the switch element through the first resistor, so that the switch element is in a conducting state, and the second output end of the switch element transmits a first electric signal output by the power supply end to the controller; when the first electric signal is smaller than a preset value, the controller sends a load disconnection instruction to the charging and discharging circuit or a load in the charging and discharging circuit is in a disconnection state.

The invention discloses a five-switch multi-mode wide-voltage-range LLC resonant converter. The five-switch multi-mode wide-voltage-range LLC resonant converter is mainly composed of a five-switch inverter stage, a resonant cavity, a high-frequency transformer and a full-wave rectifier stage. A hybrid modulation mode is adopted in a control strategy, the duty ratio is adjusted through fixed-frequency pulse width modulation (PWM) so as to increase the voltage of a direct-current bus, and the voltage gain range of more than three times is achieved in cooperation with fixed-duty-ratio pulse frequency modulation (PFM). In addition, the topology can maintain excellent soft switching characteristics in a full working range, and high-efficiency operation under wide voltage output is ensured. Compared with a traditional wide-range resonant converter, only five weighted switch tubes, one transformer and two diodes are needed, the hardware cost is remarkably reduced, the power density is improved, and the wide-range resonant converter has remarkable engineering application value.

The utility model provides a bidirectional DCDC transformer for a charging and discharging all-in-one machine, which comprises two groups of combined frameworks, supplementary frameworks are arranged on the same sides of the two combined frameworks, transformer group windings are arranged in the combined frameworks and the supplementary frameworks, and the two supplementary frameworks are connected in parallel; a plurality of opposite connecting plates are arranged in the single-group combined framework, transformer group winding wires are arranged in the opposite connecting plates in the same group and are connected in series, and the transformer group winding wires in the opposite connecting plates are communicated with the transformer group winding wires in the supplementary framework; two groups of transformer group windings in the two combined frameworks are mutually connected in parallel; according to the utility model, a two-path phase-shifted full-bridge interleaving parallel connection mode is adopted, a compact UU structure is selected, the size of the system is reduced, non-uniform load current caused by device deviation is reduced through phase-shifted modulation compensation, the output voltage is modulated and controlled by pulse frequency, the interleaving angle between the two paths of LLC resonant converters is dynamically adjusted according to the size of a phase-shifted angle, and the phase-shifted phase-shifted full-bridge resonant converter is realized. And the output current ripple is further reduced.