Programmable low noise amplifier and method
First Claim
1. A programmable gain low noise amplifier comprising:
- (a) a tail current transistor having a source coupled to a first reference voltage and a drain coupled to a tail current conductor;
(b) a plurality of input transistors each having a gate coupled to an input conductor, a drain coupled to an output conductor, and a source coupled to the tail current conductor;
(c) a plurality of switch transistors for selectively coupling the sources of at least some of the input transistors to the tail current conductor in response to a plurality of gain selection signals, respectively; and
(d) a load resistor coupled between the output conductor and a second reference voltage.
1 Assignment
0 Petitions
Accused Products
Abstract
A programmable gain low noise amplifier includes a tail current transistor (Q3) having a source coupled to a first reference voltage (VDD) and a drain coupled to a tail current conductor (18) and, in a differential input embodiment, a plurality of pairs (Q4,5, Q7,8, Q10,11, Q13,14) of differentially coupled input transistors. Each pair includes a first input transistor having a gate coupled to a first input conductor (19A) and a drain coupled to a first output conductor (26A) and a second input transistor having a gate coupled to a second input conductor (19B), a source coupled to a source of the first transistor, and a drain coupled to a second output conductor (26B). The sources of the first and second input transistors of some or all of the pairs are selectively coupled to the tail current conductor (18) in it response to corresponding gain control signals (B1,2,3).
10 Citations
23 Claims
-
1. A programmable gain low noise amplifier comprising:
-
(a) a tail current transistor having a source coupled to a first reference voltage and a drain coupled to a tail current conductor;
(b) a plurality of input transistors each having a gate coupled to an input conductor, a drain coupled to an output conductor, and a source coupled to the tail current conductor;
(c) a plurality of switch transistors for selectively coupling the sources of at least some of the input transistors to the tail current conductor in response to a plurality of gain selection signals, respectively; and
(d) a load resistor coupled between the output conductor and a second reference voltage. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A programmable gain low noise amplifier comprising:
-
(a) a tail current transistor having a source coupled to a first reference voltage and a drain coupled to a tail current conductor;
(b) a plurality of pairs of differentially coupled transistors, each pair including a first transistor having a gate coupled to a first input conductor and a drain coupled to a first output conductor and a second transistor having a gate coupled to a second input conductor, a source coupled to a source of the first transistor, and a drain coupled to a second output conductor, the sources of the first and second transistors of each pair being coupled to the tail current conductor;
(c) a plurality of switch transistors for coupling the sources of the first and second transistors of at least some of the pairs to the tail current conductor in response to a plurality of gain selection signals, respectively; and
(d) a first load resistor coupled between the first output conductor and a second reference voltage and a second load resistor coupled between a second output conductor and the second reference voltage. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
-
-
17. A programmable gain low noise amplifier comprising:
-
(a) a tail current transistor having a source coupled to a first reference voltage and a drain coupled to a tail current conductor;
(b) a plurality of input transistors each having a gate coupled to a first input conductor and a drain coupled to a first output conductor;
(c) means for selectively coupling the sources of at least some of the input transistors to the tail current conductor in response to a plurality of gain selection signals, respectively; and
(d) a load resistor coupled between the first output conductor and a second reference voltage.
-
-
18. A method of providing programmable gain in a low noise amplifier, comprising:
-
(a) generating a tail current in a tail current transistor having a source coupled to a first reference voltage and a drain coupled to a tail current conductor;
(b) providing a plurality of input transistors each having a gate coupled to an input conductor and a drain coupled to a first output conductor; and
(c) selectively coupling the sources of at least some of the input transistors to the tail current conductor in response to a plurality of gain selection signals, respectively. - View Dependent Claims (19)
-
-
20. A programmable gain low noise amplifier, comprising:
-
(a) means for generating a tail current in a tail current transistor having a source coupled to the first reference voltage and a drain coupled to a tail current conductor;
(b) a plurality of input transistors each including an input transistor having a gate coupled to a first input conductor and a drain coupled to a first output conductor;
(c) a load device coupled between the output conductor and a second reference voltage; and
(d) means for selectively coupling the sources of at least some of the input transistors to the tail current conductor in response to a plurality of selection signals, respectively, by means of a plurality of switch transistors.
-
-
21. A programmable gain low noise amplifier comprising:
-
(a) a tail current transistor having a source coupled to a first reference voltage and a drain coupled to a tail current conductor;
(b) a plurality of pairs of differentially coupled transistors, each pair including a first transistor having a gate coupled to a first input conductor and a drain coupled to a first output conductor and a second transistor having a gate coupled to a second input conductor, a source coupled to a source of the first transistor, and a drain coupled to a second output conductor, the sources of the first and second transistors of each pair being coupled to the tail current conductor;
(c) means for coupling the sources of the first and second transistors of at least some of the pairs to the tail current conductor in response to a plurality of gain selection signals, respectively; and
(d) a first load resistor coupled between the first output conductor and a second reference voltage and a second load resistor coupled between a second output conductor and the second reference voltage.
-
-
22. A method of providing programmable gain in a low noise amplifier, comprising:
-
(a) generating a tail current in a tail current transistor having a source coupled to a first reference voltage and a drain coupled to a tail current conductor;
(b) providing a plurality of pairs of differentially coupled transistors, each pair including a first transistor having a gate coupled to a first input conductor and a drain coupled to a first output conductor and a second transistor having a gate coupled to a second input conductor, a source coupled to a source of the first transistor, and a drain coupled to a second output conductor; and
(c) selectively coupling the sources of the first and second transistors of at least some of the pairs to the tail current conductor in response to a plurality of gain selection signals, respectively.
-
-
23. A programmable gain low noise amplifier, comprising:
-
(a) means for generating a tail current in a tail current transistor having a source coupled to the first reference voltage and a drain coupled to a tail current conductor;
(b) a plurality of pairs of differentially coupled transistors, each pair including a first transistor having a gate coupled to a first input conductor and a drain coupled to a first output conductor and a second transistor having a gate coupled to a second input conductor, a source coupled to a source of the first transistor, and a drain coupled to a second output conductor;
(c) means for coupling the sources of the first and second transistors to the tail current conductor in response to in response to a plurality of selection signals, respectively;
(d) a first load device coupled between the first output conductor and a second reference voltage and a second load device coupled between a second output conductor and the second reference voltage; and
(e) means for selectively coupling the sources of the first and second transistors of at least some of the pairs to the tail current conductor in response to a plurality of selection signals, respectively, by means of a plurality of switch transistors.
-
Specification