Amplifier circuit
AssigneeSony Semiconductor Solutions Corporation
InventorYoshikatsu Jingu
Life of this patent
Estimating the term…
Abstract
Linearity is improved in an amplifier circuit without lowering gain. The amplifier circuit includes a transistor, a load, an impedance element, and a variable current source. The transistor amplifies an input signal. The load is connected between the transistor and a power supply. The impedance element is connected between the transistor and a ground terminal, and passes a direct current. The variable current source is connected to a connection part between the transistor and the impedance element, and supplies a current in accordance with a voltage of the connection part.
Claims11
An amplifier circuit comprising:
- a transistor that amplifies an input signal;
- a load connected between the transistor and a power supply;
- an impedance element that is connected between the transistor and a ground terminal and passes a direct current;
- and
- a variable current source that is connected to a connection part between the transistor and the impedance element and supplies a current in accordance with a voltage of the connection part, the variable current source including:
- an additional transistor having a drain connected to the connection part,
- a capacitor connected between the connection part and a gate of the additional transistor,
- a resistor having one end connected to the gate of the additional transistor, and
- a bias voltage source connected between another end of the resistor and the ground terminal.
An amplifier circuit comprising:
- first and second transistors that amplify differential input signals;
- first and second loads respectively connected between the first and second transistors and a power supply;
- a current source having one end connected to a ground terminal;
- first and second impedance elements that are respectively connected between the first and second transistors and another end of the current source and pass a direct current;
- a first variable current source that has one end connected to a first connection part between the first transistor and the first impedance element and supplies a current in accordance with a voltage of the first connection part;
- a second variable current source that has one end connected to a second connection part between the second transistor and the second impedance element and supplies a current in accordance with a voltage of the second connection part;
- a third variable current source that has one end connected to the first connection part and supplies a current in accordance with the voltage of the second connection part;
- and
- a fourth variable current source that has one end connected to the second connection part and supplies a current in accordance with the voltage of the first connection part, wherein
- each of the first to fourth variable current sources has another end connected to the another end of the current source.
Dependencies are inferred from the claim text.