Variable gain amplifier embedded in a reception chain
AssigneeSTMicroelectronics S.r.l.
InventorRenald Boulestin
Life of this patent
Estimating the term…
Abstract
A variable-gain amplifier includes two amplification and attenuation branches, and first and a second resistive elements that are coupled between the two branches. Each branch includes a voltage follower stage and a configurable amplification stage. The voltage follower stages are intended to receive a differential signal and are configured to deliver, via the first resistive element, an intermediate differential current signal. The amplification stages are intended to receive the intermediate differential current signal and a digital control word, and are configured to deliver, via the second resistive element, an output differential voltage signal depending on the value of the digital control word.
Claims20
A variable-gain amplifier comprising:
- a first amplification and attenuation branch;
- a second amplification and attenuation branch;
- a first resistive element coupled between the first amplification and attenuation branch and the second amplification and attenuation branch;
- a second resistive element coupled between the first amplification and attenuation branch and the second amplification and attenuation branch;
- wherein the first and second amplification and attenuation branches each include a voltage follower stage and a configurable amplification stage;
- wherein the voltage follower stages are configured to receive a differential signal and to deliver, via the first resistive element, an intermediate differential current signal;
- and
- wherein the amplification stages are configured to receive the intermediate differential current signal and a digital control word, and to deliver, via the second resistive element, an output differential voltage signal that depends on the value of the digital control word.
A circuit comprising:
- a first voltage follower stage with an input coupled to receive a first differential signal;
- a second voltage follower stage with an input coupled to receive a second differential signal;
- a first resistive element coupled between the first voltage follower stage and the second voltage follower stage;
- a first configurable amplification stage coupled to the first and second voltage follower stages via the first resistive element;
- a second configurable amplification stage coupled to the first and second voltage follower stages via the first resistive element;
- a second resistive element coupled between the first configurable amplification stage and the second configurable amplification stage;
- and
- a variable-gain controller with a digital word output coupled to the first and second configurable amplification stages.
A method of operating variable-gain that comprises a first amplification and attenuation branch, a second amplification and attenuation branch, a first resistive element coupled between the first amplification and attenuation branch and the second amplification and attenuation branch, a second resistive element coupled between the first amplification and attenuation branch and the second amplification and attenuation branch, wherein the first and second amplification and attenuation branches each include a voltage follower stage and a configurable amplification stage, the method comprising:
- receiving a differential signal at the voltage follower stages;
- delivering an intermediate differential current signal from the voltage follower stages via the first resistive element;
- receiving the intermediate differential current signal at the amplification stages;
- receiving a digital control word at the amplification stages;
- and
- generating an output differential voltage signal that depends on the value of the digital control word.
Dependencies are inferred from the claim text.