2results about How to "Achieve zero current shutdown" patented technology

This application discloses a resonant DC / DC converter, system, method, and controller, including: a primary-side circuit, a resonant cavity, a secondary-side circuit, and a controller; the first terminal of the primary-side circuit is connected to a DC source, the second terminal of the primary-side circuit is connected to the first terminal of the resonant cavity, and the second terminal of the resonant cavity is connected to the secondary-side circuit; the controller is used to achieve zero-current turn-off of the primary-side circuit's switching transistor when the gain of the resonant DC / DC converter is less than 1, and when the gain of the resonant DC / DC converter is greater than 1, and when the switching frequency of the resonant DC / DC converter is greater than the resonant frequency of the resonant cavity, to achieve zero-current turn-off of the primary-side circuit's switching transistor. Thus, during startup, the switching transistor of the primary-side circuit of the resonant DC / DC converter can achieve zero-current turn-off, protecting the switching transistor.

The invention provides a push-pull conversion topology and a switching power supply, and the push-pull conversion topology comprises a transformer which comprises a first primary winding, a second primary winding and a secondary winding; the primary side circuit comprises a first switching tube, a second switching tube and a resonant inductor, and the resonant inductor comprises a first winding and a second winding; the secondary circuit comprises an output rectifying circuit and a resonant capacitor, and the resonant capacitor is connected between the first input end of the output rectifying circuit and one end of the secondary winding or between the second input end of the output rectifying circuit and the other end of the secondary winding; wherein one end of the first primary winding, the other end of the second primary winding and one end of the secondary winding are dotted terminals; one end of the first winding and the other end of the second winding are dotted terminals; and the resonant inductor and the resonant capacitor form a resonant network for realizing soft switching of the first switching tube and the second switching tube. The driving circuit has the advantages of realization of soft switching of the primary side switching tube, simple driving circuit, low cost and the like.