US 2023/0361727 A1Published application

Variable-gain amplifier, corresponding device and method

AssigneeSTMicroelectronics S.r.I.

InventorGaetano Cosentino

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Abstract

A circuit includes an amplifier and a feedback network coupled between the input and the output of the amplifier. The feedback network includes a plurality of parallel coupled branches, each branch having a first selection switch coupled to the input, a second selection switch coupled to the output, and an impedance between the first and second selection switches. Each branch includes a plurality of signal feedback paths coupled in parallel, each having a tuning switch coupled between the first selection switch and the second selection switch of that branch. A control unit is coupled to the feedback network and configured to vary a gain of the amplifier by selectively placing the first and second selection switches of each branch in a conductive state or a non-conductive state and selectively activating respective tuning switches of any branch having first and second selection switches in the conductive state.

Claims22

Dependent claims

A circuit, comprising:

an amplifier having an input node and an output node configured, an output signal carried at the output node being a replica of an input signal carried at the input node having a variable gain applied thereto;
and
a feedback network comprising a variable-impedance feedback branch coupling the output node of the amplifier to the input node of the amplifier;
wherein the gain applied to the input signal is a function of an impedance value of the variable-impedance feedback branch;
wherein the variable-impedance feedback branch comprises a plurality of sections, each section of the variable-impedance feedback branch comprising insertion switch circuitry and gain-control switch circuitry;
wherein the insertion switch circuitry is configured to be controllably switched between a conductive state wherein a feedback signal path from the output node of the amplifier to the input node of the amplifier is provided through the respective section of the variable-impedance feedback branch in response to the respective insertion switch circuitry being in the conductive state and a non-conductive state;
wherein the feedback signal path from the output node of the amplifier to the input node of the amplifier is interrupted in response to the insertion switch circuitry being in the non-conductive state;
wherein the gain-control switch circuitry is arranged in the feedback signal path from the output node of the amplifier to the input node of the amplifier;
and
wherein the gain-control switch circuitry is configured to selectively vary the gain applied to the input signal varying the impedance of the feedback signal path from the output node of the amplifier to the input node of the amplifier provided through the respective section of the variable-impedance feedback branch in response to the respective insertion switch circuitry being in the conductive state.

7 more elements

A circuit comprising:

an amplifier having an input node and an output node;
a feedback network coupled between the input node and the output node of the amplifier, the feedback network comprising a plurality of parallel coupled branches, each branch having a first selection switch coupled to the input node, a second selection switch coupled to the output node, and an impedance between the first selection switch and the second selection switch, wherein each branch comprises a plurality of signal feedback paths coupled in parallel, each signal feedback path comprising a tuning switch coupled between the first selection switch and the second selection switch of that branch;
and
a control unit coupled to the feedback network and configured to vary a gain of the amplifier by selectively placing the first and second selection switches of each branch in a conductive state or a non-conductive state so that the input node and the output node of the amplifier are electrically isolated from the impedance of any branch having first and second selection switches in the non-conductive state, the control unit further being configured to selectively vary the gain by varying the impedance of each feedback signal path by selectively activating respective tuning switches of any branch having first and second selection switches in the conductive state.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 18/308,850Filed 28 Apr 2023
Priority: IT 1020220000093236 May 2022
Published: 9 Nov 2023
Term ends: Not estimatedThe source records don’t support an estimate.

Classification22 codes

H03F 3/19
High-frequency amplifiers, e.g. radio frequency amplifiers: with semiconductor devices only
H03F 3/45475
Characterised by the way of implementation of the active amplifying circuit in the differential amplifier: using IC blocks as the active…
H03F 3/195
With semiconductor devices only: in integrated circuits
H03G 3/30
Automatic control: in amplifiers having semiconductor devices