US 10,243,520 B2Granted

FBDDA amplifier and device including the FBDDA amplifier

AssigneeSTMicroelectronics S.r.l.

InventorsAndrea Barbieri, Sergio Pernici

Life of this patent

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Abstract

A fully balanced differential difference amplifier includes a first differential input stage that receives an input voltage and a second differential input stage that receives a common-mode voltage. A first resistive-degeneration group is coupled to the first differential input and a second resistive-degeneration group is coupled to the second differential input. A differential output stage generates an output voltage. A first switch is coupled in parallel to the first resistive-degeneration group and a second switch is coupled in parallel with the second resistive-degeneration group. The first and second switches are driven into the closed state when the voltage input assumes a first value such that said first input stage operates in the linear region, and are driven into the open state when the voltage input assumes a second value, higher than the first value, such that the first input stage operates in a non-linear region.

Claims20

Dependent claims

A fully balanced differential difference amplifier, comprising:

a first differential input stage including a first input and a second input, the first differential input stage configured to receive on the first input an input voltage signal including an alternating component and fixed component and configured to generate a first signal;
a second differential input stage including a first input and a second input, the second differential input stage configured to receive on the first input the fixed component of the input voltage signal and configured to generate a second signal;
a differential output stage coupled to the first and second differential input stages and configured to generate first and second output signals based on the first and second signals;
a first resistive-degeneration circuit coupled between the first and second inputs of the first differential input stage;
a second resistive-degeneration circuit coupled between the first and second inputs of the second differential input stage;
and
a switching circuit coupled between the first and second inputs of the first differential input stage and between the first and second input of the second differential input stage, the switching circuit configured to couple the first input to the second input in each of the first and second differential input stages in response to the input voltage signal reaching a first threshold voltage and the switching circuit further configured to open in response to the input voltage signal reaching a second threshold value greater than the first threshold value to provide the first and second resistive-degeneration groups between the first and second inputs of the first and second differential input stages, respectively.

4 more elements

An electronic device, comprising:

signal-processing block circuitry configured to bias a capacitive sensor and acquire an input voltage signal generated at an output by the capacitive sensor, said signal-processing circuitry including:
a charge pump configured to bias the capacitive sensor;
a fully balanced differential difference amplifier configured to receive the input voltage signal from the capacitive sensor and to generate an output voltage signal that is a function of the input voltage signal, the fully balanced differential difference amplifier including,
a first differential input stage circuit configured to receive the input voltage signal from the capacitive sensor, the input voltage signal including a variable component and a fixed component;
a second differential input stage circuit configured to receive a common-mode voltage signal, the fixed component of the input voltage signal being the common-mode voltage signal;
a first resistive-degeneration group circuit coupled to the first differential input stage;
a second resistive-degeneration group circuit coupled to the second differential input stage;
and
a differential output stage circuit configured to generate an output voltage signal;
a first switch circuit coupled in parallel with the first resistive-degeneration group circuit;
a second switch circuit coupled in parallel with the second resistive-degeneration group circuit;
wherein the first and second switch circuits are configured to operate in a closed state to bypass the first and second resistive-degeneration group circuits based upon the input voltage signal having a first value, and the first and second switch circuits configured to operate in an open state so the first and second resistive-degeneration group circuits are not bypassed based upon the input voltage signal having a second value that is greater than the first value;
and
an analog-to-digital converter configured to receive the output voltage signal generated by the fully balanced differential difference amplifier and to convert the output voltage signal into a corresponding output voltage digital signal.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/790,518Filed 23 Oct 2017 · continuation
Priority: IT TO2014A098728 Nov 2014
Published: US 2018/0062588 A11 Mar 2018
Granted: 26 Mar 2019
Term ends: Not estimatedThe source records don’t support an estimate.

Classification20 codes

H03F 1/3211
Modifications of amplifiers to reduce non-linear distortion: in differential amplifiers
H03F 3/45197
Using MOSFET transistors as the active amplifying circuit: pl types
H03F 3/45273
Using MOSFET transistors as the active amplifying circuit: mirror types
H03F 3/45708
Measuring at the input circuit of the differential amplifier: controlling the common source circuit of the differential amplifier

Family

Application14/863,184Parent of this continuation · filed 23 Sep 2015
US 2018/0062588 A1Pre-grant publication · published 1 Mar 2018
US 9,800,212 B2Parent of this continuation
US 2016/0156319 A1Published application
US 10,243,520 B2This patent

From the US filing history. Foreign family members aren’t listed.