Amplifying circuit and voltage generating circuit

Patent metadata

Field	Value
Publication number	US-2025341851-A1
Application number	US-202519182572-A
Country	US
Kind code	A1
Filing date	Apr 17, 2025
Priority date	May 1, 2024
Publication date	Nov 6, 2025
Grant date	—

Abstract

An amplifying circuit includes a floating inverter amplifier and a voltage generating circuit. A threshold voltage of transistors in the floating inverter amplifier varies corresponding to an environmental condition. The voltage generating circuit is coupled with the floating inverter amplifier. The voltage generating circuit is configured to provide an operating voltage to the floating inverter amplifier. The operating voltage provided by the voltage generating circuit is linearly correlated to the threshold voltage, and the voltage generating circuit modulates a variation of the operating voltage to keep track with a variation of the threshold voltage.

First claim

What is claimed is:

1 . An amplifying circuit, comprising:
a floating inverter amplifier, wherein a threshold voltage of a transistor in the floating inverter amplifier varies corresponding to an environmental condition; and a voltage generating circuit, coupled with the floating inverter amplifier, and configured to provide an operating voltage to the floating inverter amplifier, wherein the operating voltage provided by the voltage generating circuit is linearly correlated to the threshold voltage, and the voltage generating circuit modulates a variation of the operating voltage to keep track with a variation of the threshold voltage.

2 . The amplifying circuit of claim 1 , wherein the voltage generating circuit comprises a first current generating circuit and a current-to-voltage converter circuit, wherein the first current generating circuit comprises:
a first multistage current mirror, comprising a first output end and configured to generate a first output current, wherein in response to that the first output current flows through the first output end, the first output end is configured to generate a first output voltage; and a first voltage-to-current converter circuit, coupled with the first output end to receive the first output voltage, and configured to convert the first output voltage into a first operating current; wherein the current-to-voltage converter circuit is coupled with the first voltage-to-current converter circuit to receive the first operating current, and configured to generate the operating voltage according to the first operating current, wherein the first operating current and the operating voltage are positively correlated to another threshold voltage of any transistor of the first multistage current mirror that the first output current flows through.

3 . The amplifying circuit of claim 2 , wherein the first multistage current mirror comprises:
a first current mirror, wherein a first end of the first current mirror is configured to receive a reference current, such that a second end of the first current mirror generates a first mirror current; a first bias circuit, coupled in series with the first end of the first current mirror, and configured to generate a first control signal according to the reference current; a second bias circuit, coupled in series with the second end of the first current mirror, and configured to generate a second control signal according to the first mirror current; and a first output stage, comprising the first output end, and wherein the first output stage is controlled by the first control signal and the second control signal and is configured to generate the first output current.

4 . The amplifying circuit of claim 3 , wherein the second bias circuit comprises:
a second transistor; and a third transistor, wherein the second transistor and the third transistor are diode-connected transistors, and are sequentially coupled in series between a first power end and the second end of the first current mirror, to receive the first mirror current, wherein in response to that the first mirror current flows through the second transistor and the third transistor, the second end of the first current mirror is configured to generate the second control signal, and a voltage of the first power end is greater than a voltage of a second power end.

5 . The amplifying circuit of claim 2 , wherein the first voltage-to-current converter circuit comprises:
a first resistor; an amplifier, wherein a first end of the amplifier is coupled with the first output end to receive the first output voltage, and a second end of the amplifier is coupled with the first resistor; and a sixth transistor, configured to generate the first operating current, wherein a control end of the sixth transistor is coupled with an output end of the amplifier, wherein the first resistor, the second end of the amplifier and the sixth transistor are sequentially coupled in series between a first power end and the current-to-voltage converter circuit.

6 . The amplifying circuit of claim 1 , wherein the voltage generating circuit comprises a second current generating circuit and a current-to-voltage converter circuit, wherein the second current generating circuit comprises:
a second multistage current mirror, comprising a second output end and configured to generate a second output current, wherein in response to that the second output current flows through the second output end, the second output end is configured to generate a second output voltage; and a second voltage-to-current converter circuit, coupled with the second output end to receive the second output voltage, and configured to convert the second output voltage into a second operating current, wherein the current-to-voltage converter circuit is coupled with the second voltage-to-current converter circuit to receive the second operating current, and configured to generate the operating voltage according to the second operating current, wherein the second operating current and the operating voltage are positively correlated to another threshold voltage of any transistor of the second multistage current mirror that the second output current flows through.

7 . The amplifying circuit of claim 1 , wherein the voltage generating circuit comprises a first current generating circuit, a second current generating circuit and a current-to-voltage converter circuit, wherein the first current generating circuit is configured to generate a first operating current, the second current generating circuit is configured to generate a second operating current, and the current-to-voltage converter circuit is configured to generate the operating voltage according to a sum of the first operating current and the second operating current.

8 . The amplifying circuit of claim 7 , wherein the current-to-voltage converter circuit comprises:
a second current mirror, comprising a first end and a second end, wherein the second end of the second current mirror is configured to generate a second mirror current; a third current mirror, wherein a first end of the third current mirror is coupled with the second current generating circuit to output the second operating current, and a second end of the third current mirror is configured to generate a third mirror current; a fourth current mirror, wherein a first end of the fourth current mirror is coupled with the second end of the third current mirror to receive the third mirror current, and a second end of the fourth current mirror is coupled with the first end of the second current mirror and configured to generate a fourth mirror current; a fifth current mirror, wherein a first end of the fifth current mirror is coupled with the first current generating circuit to receive the first operating current, and a second end of the fifth current mirror is coupled with the first end of the second current mirror and configured to generate a fifth mirror current; and a second resistor, wherein the first end of the second current mirror is configured to receive the fourth mirror current and the fifth mirror current, and a first end of the second resistor is coupled with the second end of the second current mirror to receive the second mirror current, wherein in response to that the second mirror current sequentially flows from the second current mirror through the first end and a second end of the second resistor, the first end of the second resistor is configured to generate the operating voltage.

9 . The amplifying circuit of claim 7 , wherein the current-to-voltage converter circuit comprises:
a second current mirror; a third current mirror, wherein a first end of the third current mirror is coupled with the second curre

Assignees

• Realtek Semiconductor Corp

Inventors

• Hong Wei-Cian

Classifications

• H03F3/2171

  with field-effect devices (H03F3/2173 - H03F3/2178 take precedence) · CPC title

• H03F3/45475

  using IC blocks as the active amplifying circuit · CPC title

• G05F3/26 Primary

  Current mirrors · CPC title

• H03F3/02

  with tubes only · CPC title