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US 7,202,708 B2Granted
Comparator with resonant tunneling diodes
AssigneeRaytheon Company
InventorsLouis Luh, Keh-Chung Wang
Life of this patent
Estimating the term…
Abstract
A comparator uses two resonant tunneling diodes (RTDs) in series with resistors of the latch element of the comparator. By inserting two RTD diodes in series with resistors, the negative resistance of the first and the second RTD diodes reduces the effective RC time constants of the resistors and latch, leading to a faster regeneration during a latching mode of the comparator than achieved with alternative designs.
Claims19
A comparator having a sample mode end a latching mode, a first comparator input, a second comparator input, and an output, the comparator comprising:
- a cross-coupled regenerative latch for regenerating, during a latching mode, a difference signal indicative of a difference between the first comparator input and the second comparator input, said cross-coupled regenerative latch comprising:
- a first and a second resistor,
- a first and a second resonant tunneling diode, wherein the first tunneling diode is coupled in series with the first resistor to form a first resistor-diode pair, and the second tunneling diode is coupled in series with the second resistor to form a second resistor-diode pair, and
- a first end a second transistor, wherein a collector of the first transistor and a base of the second transistor are connected to a first terminal of the first resistor-diode pair, a collector of the second transistor and a base of the first transistor are connected to a first terminal of the second resistor-diode pair, and an emitter of the first transistor is connected to an emitter of the second transistor;
- a third transistor coupled to the second terminal of the first resistor-diode pair;
- a fourth transistor coupled to the second terminal of the second resistor-diode pair;
- and
- a current switch circuit for switching the comparator between the sample mode and the latching mode;
- wherein the third and the fourth transistors couple the difference signal into the latch during the sample mode and are operable as a cascode amplifier to couple a latch state to the output during the latching mode.
6 more elements
A comparator comprising:
- a first, second, third, fourth, fifth, sixth, and seventh transistor, each transistor having a first terminal, a second terminal, and a control terminal;
- a current source;
- a first and a second resistor-diode pair, each of the first and second resistor-diode pair comprising a tunneling diode and a resistor coupled in series;
- where the first terminal of the first transistor is coupled to the control terminal of the second transistor, the first terminal of the second transistor is coupled to the control terminal of the first transistor, and the second terminal of the second transistor is coupled to the second terminal of the first transistor;
- where a first terminal of the first resistor-diode pair is coupled to the first terminal of the first transistor, and a first terminal of the second resistor-diode pair is coupled to the first terminal of the second transistor;
- where a second terminal of the first resistor-diode pair is coupled to the second terminal of the fifth transistor, a second terminal of the second resistor-diode pair is coupled to the second terminal of the sixth transistor;
- where the current source is coupled to the second terminal of the third transistor, and the first terminal of the third transistor is coupled to the second terminal of the first and second transistors, and the current source is coupled to the second terminal of the fourth transistor and the second terminal of the seventh transistor;
- and
- where the first terminal of the fourth transistor is coupled to provide bias current to the second terminal of the fifth transistor during sample mode.
6 more elements
A comparator comprising:
- a first, second, third, fourth, fifth, sixth, and seventh transistor, each transistor having a first terminal, a second terminal, and a control terminal;
- a current source;
- a first and a second resistor-diode pair, each of the first and second resistor-diode pair comprising a tunneling diode mid a resistor coupled in series;
- where the first terminal of the first transistor is coupled to the control terminal of the second transistor, the first terminal of the second transistor is coupled to the control terminal of the first transistor, and the second terminal of the second transistor is coupled to the second terminal of the first transistor;
- where a first terminal of the first resistor-diode pair is coupled to the first terminal of the first transistor, and a first terminal of the second resistor-diode pair is coupled to the first terminal of the second transistor;
- where a second terminal of the first resistor-diode pair is coupled to the second terminal of the fifth transistor, a second terminal of the second resistor-diode pair is coupled to the second terminal of the sixth transistor;
- where the current source is coupled to the second terminal of the third transistor, and the first terminal of the third transistor is coupled to the second terminal of the first and second transistors, and the current source is coupled to the second terminal of the fourth transistor and the second terminal of the seventh transistor;
- and
- where the first terminal of the fourth transistor is coupled to provide bias current to the second terminal of the fifth transistor;
- where the first terminal of the seventh transistor is coupled to provide bias current to the second terminal of the sixth transistor.
7 more elements
A comparator comprising:
- a first, second, third, fourth, fifth, and sixth, transistor, each transistor having a first terminal, a second terminal, and a control terminal;
- a current source;
- a first and a second tunneling diode;
- where the first terminal of the first transistor is coupled to the control terminal of the second transistor, the first terminal of the second transistor is coupled to the control terminal of the first transistor, and the second terminal of the second transistor is coupled to the second terminal of the first transistor;
- where a first terminal of the first tunneling diode is coupled to the first terminal of the first transistor, and a first terminal of the second tunneling diode is coupled to the first terminal of the second transistor,
- where a second terminal of the first tunneling diode is coupled to the second terminal of the fifth transistor, a second terminal of the second tunneling diode is coupled to the second terminal of the sixth transistor;
- where the current source is coupled to the second terminal of the third transistor, and the first terminal of the third transistor is coupled to the second terminal of the first and second transistors, and the current source is coupled to the second terminal of the fourth transistor;
- and
- where the first terminal of the fourth transistor is coupled to provide bias current to the second terminal of the fifth transistor.
6 more elements
Dependencies are inferred from the claim text.