Single flux quantum inverter circuit
AssigneeSynopsys, Inc.
InventorStephen Robert Whiteley
Life of this patent
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Abstract
A circuit can include a first sub-circuit, a second sub-circuit, and a third sub-circuit. The first sub-circuit can store a reset state or a set state, and can include a first Josephson junction (JJ), a second JJ, and a third JJ coupled in parallel using superconducting inductors. The first JJ, the second JJ, and the third JJ can be biased using a JJ-based current source. The second sub-circuit can switch the first sub-circuit to the set state in response to receiving a pulse. The third sub-circuit can switch the first sub-circuit to the reset state in response to receiving one or more pulses.
Claims18
A circuit, comprising:
- a first sub-circuit to store a reset state or a set state, the first sub-circuit comprising a first Josephson junction (JJ), a second JJ, and a third JJ coupled in parallel using superconducting inductors, wherein the first JJ, the second JJ, and the third JJ are biased using one or more JJ-based current sources, wherein the first JJ is biased using a bias current that is less than a critical current of the first JJ and greater than the critical current of the first JJ minus an input pulse amplitude that is desired to trigger the first JJ;
- a second sub-circuit to switch the first sub-circuit to the set state in response to receiving a pulse;
- and
- a third sub-circuit to switch the first sub-circuit to the reset state in response to receiving one or more pulses.
A circuit, comprising:
- a first sub-circuit comprising a first Josephson junction (JJ), a second JJ, and a third JJ coupled in parallel using superconducting inductors, wherein the first JJ, the second JJ, and the third JJ are biased using one or more JJ-based current sources, wherein the circuit has two stable states, wherein a first stable state corresponds to an absence of a persistent current circulating in a superconducting loop comprising the first JJ and the second JJ, wherein a second stable state corresponds to a presence of the persistent current circulating in the superconducting loop comprising the first JJ and the second JJ;
- a second sub-circuit to switch the first sub-circuit to the second stable state in response to receiving a pulse, wherein the first sub-circuit transitions to the second stable state when a clock pulse is received at a set terminal of the circuit that is coupled to the second sub-circuit;
- and
- a third sub-circuit to switch the first sub-circuit to the first stable state in response to receiving one or more pulses.
A single flux quantum (SFQ) cell, comprising:
- a first sub-circuit to store a first logic state or a second logic state, the first sub-circuit comprising a first Josephson junction (JJ), a second JJ, and a third JJ coupled in parallel using superconducting inductors;
- a second sub-circuit to switch the first sub-circuit to the second logic state responsive to receiving an external pulse at a first pin of the second sub-circuit;
- and
- a third sub-circuit to switch the first sub-circuit to the first logic state responsive to receiving one or more external pulses on a second pin of the third sub-circuit.
Dependencies are inferred from the claim text.