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.

A power stage controller includes: a reference circuit having a first reference input and a reference output, the first reference input adapted to be coupled to an input terminal of a power stage, and the reference circuit configured to adjust a reference voltage at the reference output responsive to whether a voltage at the first reference input is below a threshold; and a comparator having a current sense input, a second reference input, and a comparator output, the current sense input adapted to be coupled to a current terminal of the power stage, the second reference input coupled to the reference output, and the comparator output coupled to a driver input of a driver circuit configured to configured to control a driver output adapted to be coupled to a gate of a transistor of the power stage and responsive to the driver input.

A first capacitor and a second capacitor are connected in series through a neutral point on the DC side of an inverter. A first converter receives an input voltage from a power source and outputs a first DC voltage to the first capacitor. A second converter receives a common input voltage and outputs a second DC voltage to the second capacitor. A control circuit controls the first converter such that the first DC voltage is controlled in accordance with a preset first voltage command value and controls the second converter such that the second DC voltage is controlled in accordance with a second voltage command value set equivalent to the first voltage command value.

A power conversion apparatus and a synchronous rectification controller thereof are provided. At least one of a differentiation operation and an integration operation is performed on a drain voltage signal of a synchronous rectification transistor. According to at least one of a differential signal obtained by performing the differential operation and an integral signal obtained by performing the integral operation, it is determined whether to turn on the synchronous rectification transistor at the next time when the drain voltage signal is less than or equal to a turn-on threshold voltage.

System and method for regulating a power conversion system. A system controller for regulating a power conversion system includes a first controller terminal and a second controller terminal. Additionally, the system controller is configured to receive an input signal at the first controller terminal, and generate a drive signal at the second controller terminal based at least in part on the input signal to turn on or off a transistor in order to affect a current associated with a secondary winding of the power conversion system. Moreover, the system controller is further configured to determine whether the input signal is larger than a first threshold at a first time, in response to the input signal being determined to be larger than the first threshold at the first time, determine whether the input signal is smaller than a second threshold at a second time.

A switched-mode power supply includes an input, an output, and a transformer including primary and secondary windings. The power supply also includes a synchronous rectifier coupled to selectively conduct current through the secondary winding of the transformer. The synchronous rectifier includes a source, a gate and a drain terminal. The power supply further includes a controller having a supply voltage terminal and a gate terminal to supply a control signal to the gate of the synchronous rectifier, and a circuit coupled between the supply voltage terminal of the controller and at least one of the gate terminal of the controller and the drain terminal of the synchronous rectifier to supply power from the gate terminal of the controller or the drain terminal of the synchronous rectifier to the supply voltage terminal of the controller. Methods of supplying power in switched-mode power supplies are also disclosed.

A flyback converter communication channel is provided that comprises a pair of capacitors. A transmitter on a first side of a transformer for the flyback converter transmits a transmitter signal over a first one of the capacitors. The transmitter also transmits a complement of the transmitter signal over a second one of the capacitors. A receiver on a second side of the transformer controls a switch transistor responsive to a high-pass-filtered difference of the received signals from the pair of capacitors.

This disclosure provides an integrated transformer and a power converter, the integrated transformer includes: a magnetic core, including an upper cover, a lower cover, a first winding column and a second winding column; a printed wiring board, disposed between the upper cover and the lower cover, and including a first through hole corresponding to the first winding column and a second through hole corresponding to the second winding column; and a first winding, a second winding, a third winding and a fourth winding; the first winding and the third winding are wound on the first winding column and the second winding column respectively, the second winding and the fourth winding are provided at positions corresponding to the first through hole and the second through hole on the printed wiring board, and magnetic flux directions within the first winding column and the second winding column are opposite.

A resonant converter includes a transformer, a resonant network, control circuit, primary and secondary circuits. One of the primary switches is turned on from a first switching moment until a second switching moment. The resonant network is coupled between the primary circuit and the primary winding. A current of the resonant network changes a direction at a first moment between the first and second switching moments. The secondary circuit is coupled to the secondary winding. One of the secondary switches is turned on during first and second preset time interval to increase the current in a direction by the secondary winding being clamped by a preset voltage, in which the output current is increased in an opposite direction or equal to zero.

An input voltage estimate circuit for use in a power converter. The input voltage estimate circuit comprises a timer, which comprises a timer control circuit to generate a control signal in response to a request signal, a winding signal, and an output voltage signal. The control signal is coupled to transition to a first logic level in response to a request event in the request signal, and to transition to a second logic level in response to the winding signal falling below the output voltage signal. The timer comprises a primary conduction timer to generate a primary conduction time signal in response to the first logic level and the second logic level in the control signal and a secondary conduction timer to generate a secondary conduction time signal in response to the second logic level in the control signal and a second logic level in a second drive signal.