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US 11,309,839 B2Granted
High signal-to-noise ratio amplifier with multiple output modes
AssigneeMediatek Inc.
InventorsSung-Han Wen, Kuan-Ta Chen
Life of this patent
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Abstract
A multi-stage amplifier with a high signal-to-noise ratio is introduced. Multiple amplification stages are cascaded between an input terminal and an output terminal of the amplifier. A controller switches the output stage among the multiple amplification stages from a normal mode to an attenuation mode in response to the amplifier input being lower than the threshold. In the attenuation mode, the output stage provides an attenuation resistor coupled in series with the load resistor of the amplifier. Noise is successfully attenuated by the attenuation-mode output stage.
Claims17
An amplifier, comprising:
- a plurality of amplification stages, cascaded between an input terminal and an output terminal of the amplifier, wherein an output stage among the plurality of amplification stages is switched between a normal mode and an attenuation mode;
- a controller, operable to switch the output stage from the normal mode to the attenuation mode in response to an amplifier input signal at the input terminal being lower than a threshold;
- a first feedback resistor and a first switch, connected in series;
- and
- a second feedback resistor and a second switch, connected in series;
- wherein:
- when the output stage is in the normal mode, the first switch is closed and the second switch is open, and the output terminal of the amplifier is coupled to an input stage among the plurality of amplification stages via the first feedback resistor;
- and
- when the output stage is in the attenuation mode, the second switch is closed and the first switch is open, the output stage provides an attenuation resistor coupled in series with a load resistor of the amplifier, a first terminal of the attenuation resistor is coupled to the input stage via the second feedback resistor and a second terminal of the attenuation resistor is coupled to the load resistor.
6 more elements
Dependencies are inferred from the claim text.