Multi-stage amplifier with multiple sets of fixed and variable voltage rails
First Claim
1. A method of amplifying an input signal, the method comprising:
- receiving an input signal with a multi-stage amplifier;
receiving a mixed set of voltage rails, wherein each amplification stage of the multi-stage amplifier receives a set of the voltage rails and at least two of the stages of the multi-stage amplifier receive at least one variable voltage rail, wherein each variable voltage rail varies in accordance with one or more variations of an amplitude of the input signal to decrease a difference between a voltage of the input signal and voltages of the variable voltage rails;
amplifying the input signal using the multi-stage amplifier to generate an amplified input signal; and
utilizing a charge pump to dynamically vary the at least one variable voltage rail depending upon variations of a voltage level of the input signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A signal processing system and method utilizes a multi-stage amplifier to amplify an input signal. The multi-stage amplifier uses a mixed set of voltage rails to improve the operating efficiency of at least one of the amplification stages while allowing other amplification stages to operate in a predetermined operating mode. Efficiency of at least one of the stages is improved by supplying at least one variable voltage rail to an amplification stage of the multi-stage amplifier. The variable voltage rail varies in response to changes in an input signal voltage to the amplification stage. Accordingly, at least one amplification stage utilizes a variable voltage rail, and all amplification stages are supplied with a set of voltage rails that provides sufficient input signal headroom, thus, providing amplification stage efficiency and adequate voltage to allow operation of all amplification stages.
98 Citations
24 Claims
-
1. A method of amplifying an input signal, the method comprising:
-
receiving an input signal with a multi-stage amplifier; receiving a mixed set of voltage rails, wherein each amplification stage of the multi-stage amplifier receives a set of the voltage rails and at least two of the stages of the multi-stage amplifier receive at least one variable voltage rail, wherein each variable voltage rail varies in accordance with one or more variations of an amplitude of the input signal to decrease a difference between a voltage of the input signal and voltages of the variable voltage rails; amplifying the input signal using the multi-stage amplifier to generate an amplified input signal; and utilizing a charge pump to dynamically vary the at least one variable voltage rail depending upon variations of a voltage level of the input signal. - View Dependent Claims (2, 3, 4, 5, 6, 24)
-
-
7. A signal processing device comprising:
-
a multi-stage amplifier, the amplifier comprising; a first amplification stage having an output node and first and second power supply nodes, wherein during operation the first and second power supply nodes of the first amplification stage are coupled to respective first and second voltage rails, and at least one of the first and second voltage rails is a first variable voltage rail and each variable voltage rail varies in accordance with one or more variations of an amplitude of the input signal; a second amplification stage, coupled to the output node of the first amplification stage, having first and second power supply nodes, wherein during operation the first and second power supply nodes of the second amplification stage are respectively coupled to a second variable voltage rail and a third variable voltage rail; and a charge pump to dynamically vary at least one of the variable voltage rails depending upon variations of a voltage level of the input signal. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
-
-
15. A method of amplifying an input signal, the method comprising:
-
receiving first and second power supply voltages with a first amplification stage of a multi-stage amplifier; receiving third and fourth power supply voltages with a second amplification stage of the multi-stage amplifier, wherein the first power supply voltage is greater than the third power supply voltage, the third and fourth power supply voltages vary over time during operation of the multi-stage amplifier and the first and third power supply voltages are more positive than respective second and fourth power supply voltages; receiving an input signal with the multi-stage amplifier; amplifying the input signal using the multi-stage amplifier to generate an amplified input signal; and utilizing a charge pump to dynamically vary each of the variable voltage rails depending upon variations of a voltage level of the input signal. - View Dependent Claims (16, 17, 18, 19)
-
-
20. A signal processing system comprising:
-
a first amplification stage, wherein during operation the first amplification stage receives an input signal to the signal processing system and receives a fixed supply voltage and a first variable supply voltage, and the fixed supply voltage is greater than the first variable supply voltage; a second amplification stage, coupled to an output of the first amplification stage, wherein during operation the second amplification stage receives the fixed supply voltage and the first variable supply voltage; and a third amplification stage, coupled to an output of the second amplification stage, wherein during operation the third amplification stage receives a second variable supply voltage and the first variable supply voltage, wherein the fixed supply voltage is greater than a maximum second variable supply voltage; and a charge pump to dynamically vary each of the variable voltage rails depending upon variations of a voltage level of the input signal. - View Dependent Claims (21, 22, 23)
-
Specification