Class E high-frequency high-efficiency dc/dc power converter
First Claim
1. A swithing mode dc/dc power converter comprising:
- means for receiving input dc power,a Class E dc/ac power inverter having a switch operated at a switching frequency, coupled to said means for receiving input dc power and having an output with said inverter characterized by a switch voltage that is substantially zero at the time said switch is to be turned on, when the load impedance at said output is within a predetermined range of zero to slightly higher than a nominal load impedance value;
a rectifier circuit coupled to the output of said power inverter so as to rectify the ac output of said power inverter;
a matching network intercoupling said rectifier circuit and said output of said power inverter; and
means for providing dc output power from said rectifier circuit;
wherein said matching network comprises means for transforming the input impedance of said rectifier circuit to present a load impedance within said predetermined range to said output of said power inverter.
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Accused Products
Abstract
A Class E switching-mode dc/dc power converter is obtained by adding a rectifier circuit at the output of a Class E dc/ac power inverter. It can operate at high efficiency at high switching frequencies. Further, the power switch is not subjected to high power dissipation or high second-breakdown stress while it is switching between the "on" and "off" states, even if the dc load on the power converter varies over a very wide range, e.g., from open-circuit to short-circuit. The high efficiency is achieved by shaping the waveforms of switch voltage and switch current so that the transitions of those two waveforms are displaced in time from each other. Then the power switch does not experience simultaneously high voltage and high current while switching. High efficiency and low stress on the switch are achieved under all load conditions by interposing a matching network between the output of the Class E dc/ac inverter and the input of the rectifier circuit. That matching network transforms the rectifier input impedance in such a way that the impedance presented to the output of the Class E dc/ac inverter is always in the range which generates switch voltage and current waveforms that yield low power dissipation and low second-breakdown stress during switching, for any value of dc load resistance at the output of the rectifier.
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Citations
12 Claims
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1. A swithing mode dc/dc power converter comprising:
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means for receiving input dc power, a Class E dc/ac power inverter having a switch operated at a switching frequency, coupled to said means for receiving input dc power and having an output with said inverter characterized by a switch voltage that is substantially zero at the time said switch is to be turned on, when the load impedance at said output is within a predetermined range of zero to slightly higher than a nominal load impedance value; a rectifier circuit coupled to the output of said power inverter so as to rectify the ac output of said power inverter; a matching network intercoupling said rectifier circuit and said output of said power inverter; and
means for providing dc output power from said rectifier circuit;wherein said matching network comprises means for transforming the input impedance of said rectifier circuit to present a load impedance within said predetermined range to said output of said power inverter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification