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 invention relates to a crystalline form and/or maleate, phosphate, L-tartrate, and adipate of the compound represented by the structural formula I, and various crystalline forms of various salt forms, and preparation methods and applications thereof.

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: 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: A switching-type regulation driver includes a transformer, a controller, a synchronous rectifier and a drive control module. The drive control module is connected to the synchronous rectifier and the non-dotted terminal of the secondary winding respectively, and is used to detect a target parameter of a voltage across both power ends of the synchronous rectifier when the synchronous rectifier disconnects the conductive path between the non-dotted terminal of the secondary winding and the reference ground. When it is detected that the target parameter of the voltage across both power ends of the synchronous rectifier meets a preset condition, the controller controls a switching action of the first transistor so that the primary winding transmits power to the secondary winding. According to the present disclosure, the pre-stage chip may be matched with to realize a function of dynamic acceleration, and the dependence on the output pin may be reduced.

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 control method and control circuit of a switched-mode power supply, and the switched-mode power supply are provided. An operating mode of the switched-mode power supply is controlled in a first mode and a second mode according to an output feedback signal of the switched-mode power supply. One operating period of the first mode includes a switch period of a boundary conduction mode (BCM), and one operating period of the second mode includes N switch periods of BCMs and a switch period of a discontinuous conduction mode (DCM). The auxiliary switch transistor is turned on once to discharge a parasitic capacitor of the main switch transistor when the switched-mode power supply enters the next operating period from one operating period of the current second mode before the next operating period starts or the switched-mode power supply enters the first mode from the current second mode before the first mode starts.

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 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 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: 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: A switching-type regulation driver comprises a transformer, a controller, a synchronous rectifier and a drive control module. The drive control module is connected to the synchronous rectifier and the non-homonymous end of the secondary winding respectively, and is used to detect a target parameter of the voltage at both power ends of the synchronous rectifier when the synchronous rectifier disconnects the conductive path between the non-homonymous end of the secondary winding and the reference ground. When it is detected that the target parameter of the voltage at both power ends of the synchronous rectifier meets a preset condition, the controller controls a switching action of the first transistor so that the primary winding transmits power to the secondary winding. According to the present disclosure, the pre-stage chip may be matched with to realize a function of dynamic acceleration, and the dependence on the output pin may be reduced.

Abstract: A controller having an on-time controller, an off-time controller, a switch control signal generator, and a jittering signal generator, wherein the jittering signal generator couples jitter into the on-time or the off-time of a primary switch of the power supply. Therefore the EMI performance may be improved.

Abstract: One embodiment of the present invention discloses a switch-mode power supply controller and associated method. In an embodiment, the controller comprises an on-time controller, an off-time controller, a switch control signal generator, and a jittering signal generator, wherein the jittering signal generator couples jitter into the on-time or the off-time of a primary switch of the power supply. Therefore the EMI performance may be improved.