Abstract: A switching power supply includes a secondary control circuit coupled to a secondary side of a transformer of the switching power supply, and a primary control circuit coupled to a primary side of the transformer. The secondary control circuit is configured to receive a power request signal of a load device, and encode the power request signal to generate encoded information. The primary control circuit is configured to receive, by use of the transformer, a feedback signal reflecting an output voltage of the switching power supply, decode the encoded information based on a change of the feedback signal, and based thereon, control the switching power supply to supply power to the load device.

Abstract: A switching power supply includes a secondary control circuit coupled to a secondary side of a transformer of the switching power supply, and a primary control circuit coupled to a primary side of the transformer. The secondary control circuit is configured to receive a power request signal of a load device, and encode the power request signal to generate encoded information. The primary control circuit is configured to receive, by use of the transformer, a feedback signal reflecting an output voltage of the switching power supply, decode the encoded information based on a change of the feedback signal, and based thereon, control the switching power supply to supply power to the load device.

Abstract: A standby method for a switching power supply may be applied to a switching power supply provided with an optical coupler circuit. The method includes: upon detecting a mode control signal indicating that a load device power supply demand is greater than a preset value, entering a first mode, and controlling output voltage of the switching power supply by means of an optical coupler circuit; and upon detecting a mode control signal indicating that the load device power supply demand is less than or equal to the preset value, entering a second mode, turning off a bias current of the optical coupler circuit, and controlling the output of the switching power supply by means of a driving pulse signal, so as to reduce bias currents of a primary side and a secondary side of the switching power supply, and reduce standby power consumption of the switching power supply.

Abstract: Aa switching power supply is provided. The switching power supply may include: a protocol circuit disposed on a secondary side of the switching power supply and configured to detect a power supply demand of a load device connected to the protocol circuit; a synchronous rectifier circuit disposed on the secondary side of the switching power supply and configured to control a rectifier power tube; and a signal transmission circuit disposed between the protocol circuit and the synchronous rectifier circuit and configured to transmit a signal between the protocol circuit and the synchronous rectifier circuit.

Abstract: A system for controlling a skip mode of a switching power supply and a PWM controller are provided. The system includes a feedback signal detection circuit configured to detect an output voltage of the switching power supply and generate a feedback signal related to the output voltage; a primary winding sampling circuit coupled with a primary winding of the switching power supply and configured to sample a sampling voltage of the primary winding; a skip mode soft control circuit configured to receive the feedback signal and output an electrical signal; and a comparison circuit configured to determine a threshold for the sampling voltage, where the skip mode is activated when the feedback signal is greater than a soft activation voltage threshold, and the skip mode is pre-exited when the feedback signal is less than a predetermined voltage threshold and greater than a soft exit voltage threshold.

Abstract: A system for controlling a skip mode of a switching power supply and a PWM controller are provided. The system includes a feedback signal detection circuit configured to detect an output voltage of the switching power supply and generate a feedback signal related to the output voltage; a primary winding sampling circuit coupled with a primary winding of the switching power supply and configured to sample a sampling voltage of the primary winding; a skip mode soft control circuit configured to receive the feedback signal and output an electrical signal; and a comparison circuit configured to determine a threshold for the sampling voltage, where the skip mode is activated when the feedback signal is greater than a soft activation voltage threshold, and the skip mode is pre exited when the feedback signal is less than a predetermined voltage threshold and greater than a soft exit voltage threshold.

Abstract: Disclosed is flyback converter having a controller that performs a startup switching process when the flyback converter is powered up, and then performs normal switching afterward. The controller includes a pulse generator to generate a control signal for normal switching. During startup switching, the controller may generate a control signal by output every Nth pulse from the pulse generator. In another embodiment, the controller may generate pulses based on a sense signal provided from an input section of the flyback converter.

Abstract: Disclosed is flyback converter having a controller that performs a startup switching process when the flyback converter is powered up, and then performs normal switching afterward. The controller includes a pulse generator to generate a control signal for normal switching. During startup switching, the controller may generate a control signal by output every Nth pulse from the pulse generator. In another embodiment, the controller may generate pulses based on a sense signal provided from an input section of the flyback converter.

Abstract: A system to supply power to an electronic system, comprises a set of one or more power units each configured to transform an input voltage into an output voltage; and a line regulator coupled to a power unit and configured to modulate a duty cycle of the power unit and a load regulator configured to provide a second control signal to a power unit to selectively enable the power unit based on load information provided by the electronic system.

Abstract: A system to supply power to an electronic system, comprises a set of one or more power units each configured to transform an input voltage into an output voltage; and a line regulator coupled to a power unit and configured to modulate a duty cycle of the power unit and a load regulator configured to provide a second control signal to a power unit to selectively enable the power unit based on load information provided by the electronic system.

Abstract: A cost effective circuit improves the cross regulation of multiple outputs converter, especially for that output chokes are coupled and a synchronous rectifier is applied to one of the outputs. A DC/DC converter includes a transformer having a primary winding and two secondary windings. The first secondary winding is coupled to a synchronous rectifier and a first output choke. The second secondary winding is coupled to a diode rectifier and a second output choke. The first output choke and the second output choke are coupled. A low power MOSFET switch is added to the diode rectifier for avoiding the diode rectifier operating in DCM when light loaded.

Abstract: This invention provides an AC-to-DC power converter that improves the overall conversion efficiency especially that at the minimum input ac voltage for universal input operation design by adopting a new combination of control strategies and topologies for the PFC pre-regulator and DC-to-DC converter. The PFC pre-regulator was arranged to provide a regulated bus voltage of which the amplitude is varied in accordance with input ac voltage by a follower boost controller to achieve best efficiency in minimum input ac voltage operation. A synchronous rectifier dual boost PFC pre-regulator was present for further reduction of the power loss in the converter. Symmetrical half-bridge or symmetrical full bridge switch devices were arranged for the primary side of DC-to-DC converter and synchronous rectification circuit with two synchronous rectifier were arranged for the secondary side of the DC-to-DC converter as combination of the AC-to-DC converter.

Abstract: A cost effective circuit improves the cross regulation of multiple outputs converter, especially for that output chokes are coupled and a synchronous rectifier is applied to one of the outputs. A DC/DC converter includes a transformer having a primary winding and two secondary windings. The first secondary winding is coupled to a synchronous rectifier and a first output choke. The second secondary winding is coupled to a diode rectifier and a second output choke. The first output choke and the second output choke are coupled. A low power MOSFET switch is added to the diode rectifier for avoiding the diode rectifier operating in DCM when light loaded.