The disclosure provides an amplifier. The amplifier includes a first transistor that receives a first input. A second transistor receives a second input. A plurality of impedance networks is coupled between the first transistor and the second transistor. At least one impedance network of the plurality of impedance networks includes a first impedance path and a second impedance path. The first impedance path is activated during single ended operation, and the second impedance path is activated during differential operation.

A voltage gain amplifier (VGA) configured to have reduced supply noise. The VGA includes first resistor, first FET, and a first current-source coupled between first and second voltage rails. The VGA includes second resistor, second FET, and second current-source coupled between the voltage rails. A variable resistor is coupled between the respective sources of the first and second FETs. Variable capacitors are coupled between the first or a third voltage rail and the sources of the first and second input FETs, respectively. If capacitors are coupled to the first voltage rail, noise cancellation occurs across the gate-to-source voltages of the FETs if an input differential signal applied to the gates of the FETs is derived from a supply voltage at the first voltage rail. If capacitors are coupled to the third rail, supply noise is reduced if the supply voltage at the third rail is generated by a cleaner regulator.

A voltage gain amplifier (VGA) configured to have reduced supply noise. The VGA includes first resistor, first FET, and a first current-source coupled between first and second voltage rails. The VGA includes second resistor, second FET, and second current-source coupled between the voltage rails. A variable resistor is coupled between the respective sources of the first and second FETs. Variable capacitors are coupled between the first or a third voltage rail and the sources of the first and second input FETs, respectively. If capacitors are coupled to the first voltage rail, noise cancellation occurs across the gate-to-source voltages of the FETs if an input differential signal applied to the gates of the FETs is derived from a supply voltage at the first voltage rail. If capacitors are coupled to the third rail, supply noise is reduced if the supply voltage at the third rail is generated by a cleaner regulator.

The disclosure provides an amplifier. The amplifier includes a first transistor that receives a first input. A second transistor receives a second input. A plurality of impedance networks is coupled between the first transistor and the second transistor. At least one impedance network of the plurality of impedance networks includes a first impedance path and a second impedance path. The first impedance path is activated during single ended operation, and the second impedance path is activated during differential operation.

A low noise amplifier includes: first and seventh transistors configured to respectively receive first and second input signals; second, third, and fifth transistors connected to the first transistor; eighth, ninth, and eleventh transistors connected to the seventh transistor; a third resistive element; fourth and tenth transistors respectively connected to the third and ninth transistors; sixth and twelfth transistors respectively connected to second and first output terminals; and first and second resistive elements.