Symmetrical DC/DC converter
AssigneeNEC Tokin Corporation
InventorsSumiko Seki, Takahiko Ito
Life of this patent
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Abstract
A symmetrical DC/DC converter selects an energy transferring direction and a step-up or a step-down operation as well as a desired step-up or a step-down ratio. The converter includes a single inductor with a pair of switching devices connected to its terminals in a symmetrical arrangement with respect to the inductor. The converter is operable as a step-up converter and a step-down converter in a manner such that one and the other of the switching devices are used as an input switch and an output switch, respectively, and that one and the other of the switching devices are conversely used as an output switch and an input switch, respectively.
Claims23
A symmetrical DC/DC converter having a first pair of terminals and a second pair of terminals and operating symmetrically in that the first pair of terminals and the second pair of terminals are used as a pair of input terminals and a pair of output terminals, respectively, and in the case that the first pair of terminals and the second pair of terminals are used as the pair of output terminals and the pair of input terminals, respectively;
- said converter comprising:
- a single inductor having first and second terminals;
- a first switching means connected to said first terminal of said single inductor and comprising first and second switching portions connected in series, said first terminal of said inductor being connected to a junction between a first terminal of said first switching portion and a first terminal of said second switching portion, second terminals of said first and second switching portions selectively acting as input or output terminals of said symmetrical DC/DC converter;
- a second switching means connected to said second terminal of said single inductor and comprising third and fourth switching portions connected in series, said second terminal of said inductor being connected to a junction between a first terminal of said third switching portion and a first terminal of said fourth switching portion, second terminals of said third and fourth switching portions selectively acting as input or output terminals of said symmetrical DC/DC converter;
- said converter being selectively operable as a step-up converter and a step-down converter, and
- wherein when said converter operates as a step-up converter,
- one of said switching means has its pair of terminals connected to an input source and operates as an input switch, in which said one of the switching portions operates to be in a closed state, and the other of the switching portions operates to be in a first state selected from an opened state and a rectifying state, and
- the other of said switching means operates as an output switch, in which one of the switching portions operates to be in a second state selected from an opened state and a rectifying state and the other of the switching portions operates to repeat an on-off control action intermittently, and
- wherein when said converter operates as a step-down converter,
- said one of said switching means operates as an output switch, in which said one of the switching portions operates to repeat an on-off control action intermittently, and said other of the switching portions operates to be the second state, and
- said other of said switching means operates an input switch, in which said one of the switching portions operate to be in a closed state, and said other of the switching portions operate to be in the first state.
A symmetrical DC/DC converter comprising:
- a single inductor having first and second terminals;
- a first switching means connected to said first terminal of said single inductor and comprising first and second switching portions connected in series, said first terminal of said inductor being connected to a junction between a first terminal of said first switching portion and a first terminal of said second switching portion, second terminals of said first and second switching portions selectively acting as input or output terminals of said symmetrical DC/DC converter;
- a second switching means connected to said second terminal of said single inductor and comprising third and fourth switching portions connected in series, said second terminal of said inductor being connected to a junction between a first terminal of said third switching portion and a first terminal of said fourth switching portion, second terminals of said third and fourth switching portions selectively acting as input or output terminals of said symmetrical DC/DC converter;
- at least one of said switching portions having a rectifying mechanism which uses a synchronous rectifying technique;
- said first and second switching means being connected in a symmetrical arrangement with respect to said inductor,
- said converter being selectively operable as a step-up converter and a step-down converter, and wherein when said converter operates as a step-up converter, one of said switching means has its pair of terminals connected to an input source and operates as an input switch and the other of said switching means operates as an output switch, and wherein when said converter operates as a step-down converter, said one of said switching means operates as an output switch and said other of said switching means has its pair of terminals connected to an input source and operates an input switch.
Dependencies are inferred from the claim text.