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US 2025/0293584 A1Published application
Two-Transistor Flyback Topology With Rompower High Efficiency Passive Clamp
AssigneeRompower Technology Holdings, LLC
InventorsIonel Jitaru, Andrei Stefan Savu
Life of this patent
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Abstract
A two-transistor flyback topology in which a portion of leakage inductance energy in the transformer is extracted and used to obtain zero voltage switching on both switching elements in any operating conditions, and in which a third low power switch eliminates parasitic oscillations and allows an operation at a determined frequency. In this topology, there are no switching losses and there are no spikes or glitches in any switching node, eliminating the need for snubbers. This topology is an “ideal two transistor flyback topology.”
Claims17
A circuit having primary and secondary sides, the circuit comprising:
- a flyback power converter including an input voltage source and a transformer having primary and secondary windings on the primary and secondary sides, respectively;
- two main switchers in series with the primary winding on the primary side;
- and
- said two main switchers are controlled by two control signals;
- the first main switch connected in between said input voltage source and the first terminal of said primary winding;
- the second main switch connected to the second terminal of said primary winding;
- parasitic capacitors across each of said two main switchers;
- a passive clamp circuit across one of said primary switchers, the passive clamp circuit comprising a clamp diode, a clamp capacitor;
- an auxiliary circuit comprising first and second rectifiers in series with each other and in series with an electronic component configured to store electromagnetic energy, the electronic component having first and second terminals;
- wherein an anode of the first rectifier is connected to the passive clamp circuit, and a cathode of the first rectifier is connected to the second terminal of electronic component;
- wherein a cathode of the second rectifier is connected to the anode of the first rectifier, and an anode of the second rectifier is connected to the first terminal of the electronic components.
8 more elements
A method of operating a circuit having primary and secondary sides, the method comprising:
- providing a flyback power converter including an input voltage source and a transformer having primary and secondary windings on the primary and secondary sides, respectively;
- providing two main switchers in series with the primary winding on the primary side;
- and
- said two main switchers are controlled by two control signals;
- a passive clamp circuit across one of said primary switchers, the passive clamp circuit comprising a clamp diode, a clamp capacitor;
- an auxiliary circuit comprising first and second rectifiers in series with each other and in series with an electronic component configured to store electromagnetic energy, the electronic component having first and second terminals;
- wherein an anode of the first rectifier is connected to the passive clamp circuit, and a cathode of the first rectifier is connected is connected to the second terminal of electronic component;
- wherein a cathode of the second rectifier is connected to the anode of the first rectifier, and an anode of the second rectifier is connected to the first terminal of the electronic components;
- and
- directing a current, flowing through a leakage inductance reflected in the primary side of the transformer, to flow through the clamp capacitor and through the first rectifier towards the auxiliary energy storage, so as to change the first charge value, thereby imparting a second charge value to flow through the second rectifier during a reverse recovery time of the clamp diode, so as to balance the electrical charger in the clamp capacitor.
7 more elements
A method of operating a circuit having primary and secondary sides, the method comprising:
- providing a flyback power converter including an input voltage source and a transformer having primary and secondary windings on the primary and secondary sides, respectively;
- providing two main switchers in series with the primary winding on the primary side;
- and
- said two main switchers are controlled by two control signals;
- parasitic capacitors across each of said two main switchers;
- an active clamp circuit across one of said primary switchers, the active clamp circuit comprising a controlled switch clamp, a clamp capacitor;
- an auxiliary circuit comprising first and second rectifiers in series with each other and in series with an electronic component configured to store electromagnetic energy, the electronic component having first and second terminals;
- wherein an anode of the first rectifier is connected to the active clamp circuit, and a cathode of the first rectifier is connected is connected to the second terminal of electronic component;
- wherein a cathode of the second rectifier is connected to the anode of the first rectifier, and an anode of the second rectifier is connected to the first terminal of the electronic components;
- directing a current, flowing through a leakage inductance reflected in the primary side of the transformer, to flow through said controlled switch clamp and through the clamp capacitor and through the first rectifier towards the auxiliary energy storage, so as to change the first charge value, thereby imparting a second charge value to flow through the second rectifier during the time said controlled switch clamp is conducting, so as to balance the electrical charger in the clamp capacitor.
7 more elements
Dependencies are inferred from the claim text.