Bridge circuits and their components
AssigneeTransphorm Inc.
InventorsJames Honea, Yifeng Wu
Life of this patent
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Abstract
A half bridge is described with at least one transistor having a channel that is capable in a first mode of operation of blocking a substantial voltage in at least one direction, in a second mode of operation of conducting substantial current in one direction through the channel and in a third mode of operation of conducting substantial current in an opposite direction through the channel. The half bridge can have two circuits with such a transistor.
Claims38
A method of operating a circuit comprising a first transistor having a single gate, a second transistor having a single gate, and an inductive component, the second transistor comprising a channel and lacking an intrinsic diode anti-parallel to the channel, the method comprising:
- biasing the first transistor on and biasing the second transistor off, allowing current to flow through the first transistor and the inductive component and blocking voltage in a first direction across the second transistor;
- changing the first transistor to an off bias while leaving the second transistor biased off, allowing the current to flow through the channel of the second transistor in a second direction;
- and
- changing the second transistor to an on bias after changing the first transistor to an off bias, wherein the current continues to flow through the channel of the second transistor in the second direction.
A method of operating a circuit comprising a first switch formed of a first single transistor having a single gate, a second switch formed of a second single transistor having a single gate and a channel, and an inductive component, the method comprising:
- biasing the second transistor on and biasing the first transistor off, allowing current to flow through the channel of the second transistor in a first direction;
- biasing the first transistor on and biasing the second transistor off, allowing current to flow through the first transistor and the inductive component, whereby a blocking voltage is present across the second transistor;
- and
- after biasing the first transistor on and biasing the second transistor off, changing the first transistor to an off bias, allowing the current to flow through the channel of the second transistor in a second direction and through the inductive component.
A circuit, comprising:
- an inductive component coupled to a switching device, the switching device comprising a depletion-mode transistor and an enhancement-mode transistor, the enhancement-mode transistor including a gate, and the depletion-mode transistor including a channel, wherein a gate of the depletion-mode transistor is electrically connected to a source of the enhancement-mode transistor and a source of the depletion-mode transistor is electrically connected to a drain of the enhancement-mode transistor;
- wherein
- the switching device is configured such that in a first mode of operation current flows through the channel of the depletion-mode transistor in a first direction when the gate of the enhancement-mode transistor is biased below a threshold voltage of the enhancement-mode transistor, and in a second mode of operation current flows through the channel of the depletion-mode transistor in the first direction when the gate of the enhancement-mode transistor is biased above the threshold voltage of the enhancement-mode transistor.
A method of operating a circuit, the circuit comprising an inductive component coupled to a first switching device and a second switching device, the second switching device comprising a depletion-mode transistor and an enhancement-mode transistor, the enhancement-mode transistor including a gate, the depletion-mode transistor including a channel, wherein a gate of the depletion-mode transistor is electrically connected to a source of the enhancement-mode transistor and a source of the depletion-mode transistor is electrically connected to a drain of the enhancement-mode transistor, the method comprising:
- flowing a current through the inductive component;
- at a first time, biasing a gate of the first switching device at a voltage lower than a threshold voltage of the first switching device and biasing the gate of the enhancement-mode transistor at a voltage lower than a threshold voltage of the enhancement-mode transistor, causing the first switching device to operate in blocking mode and the second switching device to operate in diode mode, wherein the current flows through the channel of the depletion-mode transistor in a first direction;
- and
- at a second time following the first time, changing the bias on the gate of the enhancement-mode transistor to be higher than the threshold voltage of the enhancement-mode transistor, wherein the current continues to flow through the channel of the depletion-mode transistor in the first direction.
A half bridge comprising a switch formed of a single transistor, the single transistor having a single gate, a source, a drain and a channel, wherein the half bridge is configured such that in a first mode of operation the switch blocks a substantial voltage in a first direction, in a second mode of operation the switch conducts substantial current in the first direction through the channel of the transistor, and in a third mode of operation the switch conducts substantial current in an opposite direction through the channel of the transistor, wherein in the third mode of operation the single gate is biased relative to the source at a voltage lower than a threshold voltage of the single transistor.
Dependencies are inferred from the claim text.