Dual gain amplifier circuit
AssigneeSTMicroelectronics S.r.l.
InventorBelot Didier
Life of this patent
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Abstract
A dual gain amplifier provides separate gains so that the amplifier's input characteristics are unaffected by the gain selected. The dual gain amplifier comprises a first input amplifier and a third amplifier connected in cascade, and a second input amplifier and a fourth amplifier connected in cascade. A first LC circuit is connected in parallel to a second LC circuit which are both connected to the third amplifier. Likewise, a third LC circuit is connected in parallel to a fourth LC circuit which are connected to the fourth amplifier. The first and third LC circuits have a first quality factor and the second and fourth LC circuits have a second quality factor. The dual gain amplifier switches from a first state in which only the first and third LC circuits conduct to a second state in which all four LC circuits conduct.
Claims27
A dual gain amplifier comprising:
- a first input amplifier;
- a second input amplifier;
- a third amplifier coupled to the first input amplifier for forming a first cascaded circuit;
- a fourth amplifier coupled to the second input amplifier for forming a second cascaded circuit;
- a first LC circuit and second LC circuit connected in parallel and to said third amplifier;
- a third LC circuit and fourth LC circuit connected in parallel and to said fourth amplifier;
- the first and third LC circuits having a first quality factor, and the second and fourth LC circuits having a second quality factor;
- and
- means for switching the dual gain amplifier from a first state in which only the first and third LC circuits are conducting to a second state in which all four LC circuits are conducting.
A dual gain amplifier comprising:
- a first input amplifier;
- a second input amplifier;
- a third amplifier coupled to the first input amplifier for forming a first cascaded circuit;
- a fourth amplifier coupled to the second input amplifier for forming a second cascaded circuit;
- a first LC circuit and second LC circuit connected in parallel and to said third amplifier;
- a third LC circuit and fourth LC circuit connected in parallel and to said fourth amplifier;
- the first and third LC circuits having a first quality factor and the second and fourth LC circuits having a second quality factor less than the first quality factor;
- and
- means for switching the dual gain amplifier from a first state in which only the first and third LC circuits are conducting to a second state in which all four LC circuits are conducting.
A dual gain amplifier comprising:
- a first input amplifier;
- a second input amplifier;
- a third amplifier coupled to the first input amplifier for forming a first cascaded circuit;
- a fourth amplifier coupled to the second input amplifier for forming a second cascaded circuit;
- a first LC circuit and second LC circuit connected in parallel and to said third amplifier;
- a third LC circuit and fourth LC circuit connected in parallel and to said fourth amplifier;
- the second and fourth LC circuits each comprises an inductor, and a silicon substrate portion mounting said inductor;
- the first and third LC circuits having a first quality factor and the second and fourth LC circuits having a second quality factor less than the first quality factor;
- and
- means for switching the dual gain amplifier from a first state in which only the first and third LC circuits are conducting to a second state in which all four LC circuits are conducting.
A method for providing a dual gain amplifier, comprising the steps of:
- forming a first input amplifier;
- forming a third amplifier coupled to the first input amplifier;
- forming a second input amplifier;
- forming a fourth amplifier coupled to the second input amplifier;
- connecting a first and second LC circuit in parallel and to the third amplifier;
- connecting a third and fourth LC circuit in parallel and to the fourth amplifier;
- selecting a first quality factor for the first and third LC circuits and selecting a second quality factor for the second and fourth LC circuits so that the first quality factor is greater than the second quality factor;
- and
- switching said dual gain amplifier from a first state in which only the first and third LC circuits are conducting to a second state in which all four LC circuits are conducting.
Dependencies are inferred from the claim text.