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US 10,658,987 B2Granted
Amplifier circuit for cryogenic applications
AssigneeRambus Inc.
InventorsRichelle L. Smith, Roxanne Vu, Carl W. Werner
Life of this patent
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Abstract
The embodiments herein describe technologies of an amplifier circuit that is designed for wideband communication with superconductive components in cryogenic applications, including Josephson Junction integrated circuits, operating in a cryogenic temperature domain (e.g., 4K). The amplifier circuit operates in a temperature domain (e.g., 77K) that is higher than the cryogenic temperature domain of the superconductive components.
Claims20
An amplifier circuit comprising:
- a current source;
- a first complementary transistor pair coupled between a first source node and a second source node, the first source node being coupled to the current source and the first complementary transistor pair comprising a first input terminal and a first output terminal;
- a second complementary transistor pair coupled between the first source node and the second source node, the second complementary transistor pair comprising a second input terminal and a second output terminal;
- a first shunt resistor coupled between the first input terminal and the first output terminal;
- and
- a second shunt resistor coupled between the second input terminal and the second output terminal, wherein an input impedance between the first input terminal and the second input terminal is controlled by a transconductance of the first complementary transistor pair and the second complementary transistor pair, wherein the transconductance of the first complementary transistor pair and the second complementary transistor pair is adjusted by a first magnitude of a first well body bias voltage applied to a first well of the first complementary transistor pair and by a second magnitude of a second well body bias voltage applied to a second well of the first complementary transistor pair.
3 more elements
An integrated circuit comprising:
- a first interconnect terminal and a second interconnect terminal to receive a differential input signal over a pair of conductors;
- and
- a fully-differential complementary metaloxidesemiconductor (CMOS) low-noise amplifier (LNA) circuit comprising:
- a first input node coupled to the first interconnect terminal;
- a second input node coupled to the second interconnect terminal;
- a common current source;
- a common voltage node;
- a first complementary transistor pair coupled to the first input node, the common current source, the common voltage node, and a first output node;
- a second complementary transistor pair coupled to the second input node, the common current source, the common voltage node, and a second output node;
- a first resistor coupled between the first input node and the first output node;
- and
- a second resistor coupled between the second input node and the second output node, wherein an input impedance of the fully-differential CMOS LNA circuit is controlled by a transconductance of the first complementary transistor pair and the second complementary transistor pair by applying a first magnitude of a first well body bias voltage to a first well of the first complementary transistor pair and by applying a second magnitude of a second well body bias voltage to a second well of the first complementary transistor pair.
9 more elements
A method comprising:
- applying a first input voltage across input terminals of an amplifier circuit with matched complementary transistor pairs coupled at a common source node that is coupled to a common current source, wherein the matched complementary transistor pairs having shunt resistive feedback;
- measuring a first current at the amplifier circuit;
- applying a second input voltage across the input terminals of the amplifier circuit;
- measuring a second current at the amplifier circuit;
- calculating an impedance value based on the first current, the second current, the first input voltage, and the second input voltage;
- comparing the impedance value against a specified impedance setting for the amplifier circuit;
- adjusting a transconductance parameter of the amplifier circuit;
- and
- repeating the applying the first input voltage, measuring the first current, applying the second input voltage, measuring the second current, calculating, comparing, and adjusting the transconductance parameter until the impedance value is within a specified tolerance of the specified impedance setting for the amplifier circuit.
6 more elements
Dependencies are inferred from the claim text.