CPC H03F 3/19 (2013.01) [H03H 11/04 (2013.01); H03M 1/1245 (2013.01); H03F 2200/451 (2013.01)] | 15 Claims |
1. An amplifier circuit, comprising:
first and second amplifiers, each having an input and an output;
a first attenuation circuit, having an input and an output coupled to the input of the first amplifier;
a second attenuation circuit, having an input and an output coupled to the input of the second amplifier;
a first input capacitor, coupled between the input of the first attenuation circuit and an output of the second attenuation circuit;
a second input capacitor, coupled between the input of the second attenuation circuit and an output of the first attenuation circuit; and
control logic adapted to control the first and second attenuation circuits to apply a selected attenuation to a received signal at their respective inputs;
wherein each of the first and second attenuation circuits is a digital step attenuation circuit comprising:
a digitally controllable series capacitance; and
a digitally controllable shunt capacitance;
and wherein the control logic is adapted to control the digitally controllable series capacitance and the digitally controllable shunt capacitance.
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