High-Frequency Power MESFET Boost Switching Power Supply
First Claim
1. A boost converter that includes a normally off N-channel MESFET switch that regulates the output of the converter.
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Accused Products
Abstract
A MESFET based boost converter includes an N-channel MESFET connected to a node Vx. An inductor connects the node Vx to a battery or other power source. The node Vx is also connected to an output node via a Schottky diode or a second MESFET or both. A control circuit drives the MESFET (and the second MESFET) so that the inductor is alternately connected to ground and to the output node. The maximum voltage impressed across the low side MESFET is optionally clamped by a Zener diode. In some implementations, the MESFET is connected in series with a MOSFET. The MOSFET is switched off during sleep or standby modes to minimize leakage current through the MESFET. The MOSFET is therefore switched at a low frequency compared to the MESFET and does not contribute significantly to switching losses in the converter. In other implementations, more than one MESFET is connected in series with a MOSFET, the MOSFETs being switched off during periods of inactivity to suppress leakage currents.
155 Citations
102 Claims
- 1. A boost converter that includes a normally off N-channel MESFET switch that regulates the output of the converter.
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6. A synchronous boost converter that includes:
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a low-side switch implemented using a first N-channel MESFET where the first N-channel MESFET is normally off; and a synchronous rectifier implemented using a second N-channel MESFET. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13)
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- 14. A cascode power switch comprising a MOSFET in series with a normally-off MESFET.
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25. A switch that comprises:
- a normally-off MESFET in parallel with a Zener diode, the Zener diode having an avalanche voltage that is lower than the avalanche voltage of the MESFET.
- 26. A clamped cascode switch comprising a series connection of a normally off MESFET and a MOSFET, where the MESFET is connected in parallel with a Zener diode, and where the Zener diode has an avalanche voltage lower than the avalanche voltage of the MESFET.
- 32. A clamped cascode switch comprising a series connection of a normally off MESFET and a MOSFET, where the series connected MESFET and MOSFET is connected in parallel with a Zener diode, and where the Zener diode has an avalanche voltage lower than the avalanche voltage of the MESFET.
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38. A cascode switch comprising a series connection of a normally off N-channel MESFET and an N-channel MOSFET, where the source of N-channel MOSFET is connected to the drain of the MESFET, and where the body of the N-channel MOSFET is connected to the source of the MESFET;
- and where the MOSFET includes a drain-to-body diode.
- View Dependent Claims (39, 40, 41)
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42. A cascode switch comprising a series connection of a normally off N-channel MESFET and a P-channel MOSFET, where the source of P-channel MOSFET is connected to the drain of the MESFET, and where the body of the P-channel MOSFET is connected to the source of the MESFET;
- and where the MOSFET includes a drain-to-body diode.
- View Dependent Claims (43, 44, 45)
- 46. A boost converter that includes a cascode switch comprising a series connected MESFET and MOSFET.
- 53. A synchronous boost converter that comprises a first MESFET switch with a grounded source and a synchronous rectifier comprising a second MESFET switch having neither its source nor its drain connected to ground.
- 62. A synchronous boost converter that comprises a grounded cascode switch comprising a first N-channel MESFET and a N-channel MOSFET, and a synchronous rectifier comprising a second N-channel MESFET switch having neither its source nor its drain connected to ground.
- 76. A synchronous boost converter that comprises a first N-channel MESFET with a grounded source and a P-channel MOSFET in series with an inductor, and a synchronous rectifier comprising a second N-channel MESFET switch having neither its source nor its drain connected to ground.
- 90. A synchronous boost converter that comprises a grounded cascode switch comprising an N-channel MESFET and a N-channel MOSFET, and a synchronous rectifier comprising a P-channel MOSFET switch having neither its source nor its drain connected to ground.
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102. A synchronous boost converter that comprises:
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an inductor connected between a battery and a node Vx; an N-channel MESFET; a MOSFET; and a control circuit, where the control circuit drives the MESFET and MOSFET out of phase so that the node Vx is alternately connected to ground and to an output node.
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Specification