Abstract: The provided is an on-time generator circuit and a switching converter. The on-time generator circuit includes a ramp module configured to generate a ramp signal based on a drive signal of a main power transistor and an input voltage; a compensation module configured to generate a compensation signal based on the input voltage and a duty cycle; and a timing signal generation module configured to generate a timing signal based on the ramp signal, the compensation signal, and an output feedback signal. The compensation signal is used to offset delay time generated by the timing signal, making turn-on time (Ton) be preset Ton corresponding to the duty cycle, and keeping a switching frequency constant at different duty cycles.

Abstract: A dynamic automotive turn signal circuit includes at least one drive control module configured to receive a power supply signal from a body control module (BCM) to start operation, where the drive control module outputs first control signals at different delays through a delay unit; and a light emitting diode (LED) light set connected to the drive control module and lit based on the first control signals. A dynamic automotive turn signal system is further provided. The dynamic automotive turn signal circuit and the dynamic automotive turn signal system uses an external resistor to preset a high-precision delay circuit to realize the function of dynamic flowing turn signals. The external resistor can be used to configure a turn-on delay and a turn-off delay of the internal driver chip, such that the channel turn-on time and turn-off time can be flexibly adjusted.

Abstract: A frequency regulating circuit for a switching circuit, a frequency regulating method, and the switching circuit are provided. The frequency regulating circuit includes a charging current generating module configured to receive a first signal characterizing an output power and a second signal characterizing an input voltage to generate a charging current and a signal generating module configured to output a third signal according to the charging current. The third signal is used to adjust the maximum operating frequency of the switching circuit so that the maximum operating frequency decreases with the increase of the input voltage. Therefore, the frequency regulating circuit increases the maximum operating frequency of the switching circuit under the condition of low voltage input, which decreases the maximum operating frequency of the switching circuit under the condition of high voltage input to reduce the switching loss of the switching circuit with wide input voltage and improve efficiency.

Abstract: Disclosed is a flyback converter and a control method thereof. The flyback converter comprises: a transformer; a power switch; a driver; a synchronous rectifier; and a feedback control module, wherein the feedback control module is configured to output a primary-side turn-on signal when a new switching cycle is started; in each switching cycle, the feedback control module is configured to turn off a primary-side power switch according to a voltage across the synchronous rectifier and an output voltage of the flyback converter. The flyback converter only needs a single isolation device to achieve lossless equivalent peak current control and driving interlocking of primary side and the secondary side, and the synchronous rectifier can effectively prevent driving shoot-through of the primary side and the secondary side in terms of control without reducing a drive voltage, which further improves system efficiency and reliability.

Abstract: The present disclosure relates to a flyback converter and a power supply system. The flyback converter comprises: a transformer; a first switching transistor and a second switching transistor; a first inductor and a first capacitor; and a control circuit. The control circuit includes an under voltage protection module configured to determine an under voltage protection threshold proportional to an output voltage of the flyback converter and to trigger an under voltage protection action of the flyback converter in a case that an input voltage of the flyback converter is less than the under voltage protection threshold. By setting an adaptive under voltage protection threshold, a system-restart phenomenon of the flyback converter after an input power failure or a shutdown may be avoided, and a PFC circuit may be turned off to optimize the standby power consumption and the low load efficiency in fast charging applications using an flyback topology.

Abstract: A current limiting circuit of a switching circuit, and a switching circuit are provided. The switching circuit uses a gallium nitride (GaN) power transistor as a main power transistor. The current limiting circuit includes a first terminal connected with a drain of the GaN power transistor, and a second terminal connected with a controller of the switching circuit. The current limiting circuit is configured to limit a current flowing out of a power supply terminal of the controller. The current limiting circuit suppresses a negative current flowing through the controller.

Abstract: A power supply system control method and a power supply system are provided. The control method includes: controlling a power supply system to enter a first mode based on a power parameter, a temperature parameter, and an electric quantity parameter; and during the first mode, controlling a first regulating circuit to regulate a second switching circuit such that an input voltage of the load module is adjusted to a target voltage, and controlling a first voltage loop to regulate a first switching circuit based on the power parameter, to stabilize an output voltage of a solar cell at a first threshold voltage, where the first threshold voltage is close to an output voltage corresponding to maximum output power of the solar cell.

Abstract: Disclosed is an asymmetric half-bridge flyback converter and a control method, comprising: in an initial switching cycle of the asymmetric half-bridge flyback converter, obtaining a pre-turnoff time of the second switch transistor, and controlling the second switch transistor to be turned off after a delay which lasts for a first time and starts at the pre-turnoff time of the second switch transistor; in a non-initial switching cycle of the asymmetric half-bridge flyback converter, obtaining a judgment result by judging whether the first switch transistor is operated with zero-voltage switching in a current switching cycle, and adjusting a length of the first time based on the judgment result. The present disclosure can realize zero-voltage switching of the asymmetric half-bridge flyback converter, and at the same time, satisfy a requirement for achieving more ideal dead-time setting under a wider range of input voltage and a wider range of output voltage.

Abstract: A flyback converter, a constant-current control method, and a lighting system are provided. The constant-current control method includes: sampling a loop current in a resonant loop to obtain a first sampling signal; obtaining zero crossing time of an excitation current in the resonant loop; and turning off a first switch tube when the first sampling signal reaches a reference value, and turning off a second switch tube after the zero crossing time of the excitation current in the resonant loop to control an average value of the excitation current to keep constant. The present disclosure can achieve a constant average value of an excitation current in each switching cycle based on a loop current in a resonant loop on the primary side of the converter, thereby realizing constant-current control of an output current of the converter.

Abstract: Disclosed is a switch protection circuit and a power converter, configured to set upper and lower limit-value current signals which can be adjusted along with an input voltage, so that instantaneous power of a main power switch can be prevented from being too high, and the main power switch can always be operated within a safe operating range, thereby solving the problem that the power converter is easy to be damaged in applications under a high-current circumstance.

Abstract: A switched-mode power supply includes a first switch transistor. A drain of the first switch transistor receives an input voltage on a direct current input bus of the switched-mode power supply, and a source is connected to a reference ground. The power supply circuit includes a junction field-effect transistor (JFET), where a drain of the JFET receives the input voltage, a gate is connected to the reference ground, and a source outputs a supply voltage or a supply current. During each switch cycle, the first switch transistor is controlled to be turned off or a drain voltage is controlled to be greater than or equal to a first threshold voltage when the first switch transistor is turned on, such that the supply voltage or the supply current satisfies a drive voltage of the first switch transistor and an operating voltage of a to-be-powered circuit of the switched-mode power supply.

Abstract: A light source driving circuit and a communication device for a display system are provided. The communication device includes a control unit and at least one string light source driving circuit. The control unit includes an output interface for transmitting the control commands or data and a reading back data input interface. Each string light source driving circuit includes a plurality of light source driving circuits. The control unit transmits the control commands or data to the first light source driving circuit of each string light source driving circuit through the output interface. The first driving circuit takes out the commands or data required at the current stage after receiving the control command or data, and then repackages the commands or data of the remaining driving circuits, and transmits the repackaged data packet through the serial output interface and the parallel interfaces or the parallel interfaces.

Abstract: A light source driving circuit and a communication device for display system are provided. The communication device includes a control unit and at least one string light source driving circuit. The control unit includes an output interface for transmitting control commands or data and a data reading back input interface. Each string light source driving circuit includes a plurality of light source driving circuits, and each light source driving circuit interface includes a serial input interface, a serial output interface, parallel interfaces, and at least one current output interface. The serial input interface and serial output interface of the plurality of light source driving circuits are cascaded with each other as a first channel of the control commands or data transmission. The parallel interfaces of each driving circuit in the plurality of driving circuits are coupled with each other as a second channel of the control commands and data transmission.

Abstract: Disclosed is an asymmetric half-bridge flyback converter and a control method, including: in an initial switching cycle of the asymmetric half-bridge flyback converter, obtaining a pre-turnoff time of the second switch transistor, and controlling the second switch transistor to be turned off after a delay which lasts for a first time and starts at the pre-turnoff time of the second switch transistor; in a non-initial switching cycle of the asymmetric half-bridge flyback converter, obtaining a judgment result by judging whether the first switch transistor is operated with zero-voltage switching in a current switching cycle, and adjusting a length of the first time based on the judgment result. The present disclosure can realize zero-voltage switching of the asymmetric half-bridge flyback converter, and at the same time, satisfy a requirement for achieving more ideal dead-time setting under a wider range of input voltage and a wider range of output voltage.

Abstract: Disclosed is a soft switch control circuit and a flyback converter, comprising a primary edge part and a secondary edge part, and obtaining a trigger pulse signal according to a pre-turning on signal of a main switch transistor before the main switch transistor is turned on. The trigger pulse signal is transmitted to the secondary edge part by an isolation module to control the switch at a secondary edge circuit to conduct, to reduce source-drain voltage of the main switch circuit of the primary edge, to make the main switch transistor to turn on when the source-drain voltage is near zero voltage. The switch of the secondary edge circuit is a synchronous rectifying switch transistor or a discharge switch transistor connected at two ends of the synchronous rectifying switch transistor.

Abstract: The present disclosure relates to a buck-boost converter and a control method therefor. The buck-boost converter includes a boost unit and a buck unit. The boost unit has a first capacitor and a first group of switches. The buck unit has an inductor and a second group of switches. The buck-boost converter has a cascaded structure of the boost unit and the buck unit to achieve multiple voltage conversion modes. The inductor of the buck unit is coupled to the output terminal. Therefore, not only can it achieve a smooth transition of the DC output voltage, but also reduce voltage ripple and improve dynamic response speed.

Abstract: Disclosed is a protection circuit of a flyback converter and a control method. The protection circuit comprises: an active discharge module, connected to at least one end of a first capacitor in a resonance circuit of the flyback converter to provide a discharge path, and controlling turning-on and turning-off of the discharge path according to the discharge enable signal; in a normal work state, the discharge path is disconnected, the first capacitor works as a resonance capacitor; before the flyback converter is restarted, the discharge path is turned on for a predetermined time period to release charges of the first capacitor, a resonance current after the flyback converter is restarted is reduced to a safe work current of the second switch transistor. Charges stored in the first capacitor can be discharged to release before the flyback converter is restarted to reduce the resonance current and enhance system stability and security.

Abstract: Disclosed is a protection circuit of a flyback converter and a control method. The protection circuit comprises: an active discharge module, for providing a discharge path between a first current terminal and a second current terminal of a switch transistor in a resonance circuit, and controlling turning-on and turning-off of the discharge path according to a discharge enable signal; in the normal work state of the flyback converter, the discharge path is disconnected, the resonance circuit works, before the flyback converter is restarted, the discharge path is turned on for a predetermined time period to release charges stored in the resonance circuit, and the resonance current after the flyback converter is restarted is reduced to the safe work current of the second switch transistor. The resonance current is discharged before the flyback converter is restarted, thus reducing the resonance current and enhancing system stability and security.

Abstract: A supply circuit and a switched mode power supply (SMPS) are provided. The supply circuit includes a first capacitor, a second capacitor, and a charging-discharging control circuit; the first capacitor includes a first terminal connected to a switching node, and a second terminal for providing a first supply voltage; the second capacitor includes a first terminal connected to a reference ground or a first potential terminal under control of the charging-discharging control circuit, and a second terminal for providing a second supply voltage; and according to a charging-discharging enable signal, the charging-discharging control circuit charges the second capacitor in a first time period and discharges the second capacitor in a second time period.

Abstract: Disclosed is a semiconductor device and a manufacturing method, comprising: forming a pad oxide layer and a silicon nitride layer on a substrate; etching the silicon nitride layer into a plurality of segments; forming an oxide layer, having an up-and-down wave shape, by performing a traditional thermal growth field oxygen method on the semiconductor device by use of the plurality of segments serving as forming-assisted structures; performing traditional processes on the semiconductor device having an up-and-down wavy semiconductor surface, to form a gate oxide layer, a polysilicon layer, and to form a source region and a drain region by implantation The semiconductor device having an up-and-down wavy channel region may be formed by a traditional thermal growth field oxygen method, thus the manufacturing processes are simple, the cost is low, and the completed device may have a larger effective channel width and a lower on-state resistance.