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US 6,496,068 B1Granted
Multi-stage amplifier circuit
AssigneeApex Microtechnology Corporation
InventorDennis Eddlemon
Life of this patent
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Abstract
An amplifier circuit that includes an amplifier stage and an output stage, and local feedback between these stages to drive a biasing string associated with the amplifier stage using the potential at the output stage. In one embodiment, the local feedback line is coupled between the output stage and the biasing string to remove the loading effect of the biasing string on the amplifier stage. In another embodiment, the local feedback line is coupled between the switches of the amplifier stage and the switches of the output stage to bias the amplifier stage using the output stage.
Claims34
An amplifier circuit comprising:
- a positive supply rail and a negative supply rail;
- a first plurality of switches stacked between said positive and negative supply rails, a biasing string comprising a plurality of RC circuits stacked between said positive and negative supply rails, one of said switches receiving an external control signal to control the conduction switches;
- and
- a feedback line from said second plurality of switches to said biasing string operable to drive said plurality of RC circuits using power from said second plurality of switches;
- wherein said first plurality of switches comprises a first, second, third and fourth switch arranged in a series stacked relationship between said positive and negative supply rails, said first switch receiving said control signal to control the conduction state thereof and coupled to said positive supply rail, and said fourth switch configured to operate as a current source wherein the conduction state thereof is controlled by said negative supply rail, said switches defining a first node between said first and second switch, a second node between said second and third switch, and a third node between said third and fourth switch;
- wherein said biasing string comprises a first, second, third and fourth parallel arrangement of said RC circuits arranged in a series stacked relationship between said positive and negative supply rails, said RC circuits dividing the potential between said positive and negative supply rails and defining a fifth node between said first and second RC circuits and a sixth node between said third and fourth RC circuits, the potential at said fifth node controlling the conduction state of said second switch, the potential at said sixth node controlling the conduction state of said third switch.
3 more elements
An amplifier circuit comprising:
- a positive supply rail and a negative supply rail;
- a first plurality of switches stacked between said positive and negative supply rails, a biasing string comprising a plurality of RC circuits stacked between said positive and negative supply rails, one of said switches receiving an external control signal to control the conduction state thereof, another of said switches being arranged as a current source;
- a second plurality of switches stacked between said positive and negative supply rails, the conduction state there of being controlled by the conduction state of said first plurality of switches;
- and
- a feedback line from said second plurality of switches to said biasing string operable to drive said plurality of RC circuits using power from said second plurality of switches;
- wherein the potential between said positive and negative rails is divided substantially equally between said RC circuits.
3 more elements
An amplifier circuit comprising:
- a positive supply rail and a negative supply rail;
- a first plurality of switches stacked between said positive and negative supply rails, a biasing string comprising a plurality of RC circuits stacked between said positive and negative supply rails, one of said switches receiving an external control signal to control the conduction state thereof, another of said switches being arranged as a current source;
- a second plurality of switches stacked between said positive and negative supply rails, the conduction state thereof being controlled by the conduction state of said first plurality of switches;
- and
- a feedback line from said second plurality of switches to said biasing string operable to drive said plurality of RC circuits using power from said second plurality of switches;
- wherein said feedback line is operable to remove said plurality of RC circuits as a load to said first plurality of switches.
3 more elements
An amplifier circuit, comprising:
- an input stage operable to produce a differential input signal;
- a second stage operable to amplify said input signal;
- an output stage operable to deliver said amplified signal to a load;
- and
- a local feedback line between said output stage and said second stage, said feedback line operable to bias said second stage with the potential of said output stage;
- wherein said second stage comprises a first plurality of switches stacked between positive and negative supply rails, a biasing string comprising a plurality of RC circuits stacked between said positive and negative supply rails, one of said switches receiving an external control signal to control the conduction state thereof, another of said switches being arranged as a current source;
- and wherein said output stage comprises a second plurality of switches stacked between said positive and negative supply rails, the conduction state thereof being controlled by the conduction state of said first plurality of switches.
4 more elements
A method of amplifying a signal, comprising the steps of:
- passing an input signal through an amplifier stage comprising a plurality of first switches stacked between positive and negative power supply rails;
- controlling the conduction state of said first switches to amplify and pass said signal to an output stage comprising a plurality of second switches stacked between said positive and negative power supply rails;
- providing a local feedback line between said amplifier stage and said output stage so that said output stage controls the biasing of said amplifier stage;
- and
- coupling a biasing string to said first plurality of switches to load said first plurality of switches.
2 more elements
A method of amplifying a signal, comprising the steps of:
- passing an input signal through an amplifier stage comprising a plurality of first switches stacked between positive and negative power supply rails;
- controlling the conduction state of said first switches to amplify and pass said signal to an output stage comprising a plurality of second switches stacked between said positive and negative power supply rails;
- providing a local feedback line between said amplifier stage and said output stage so that said output stage controls the biasing of said amplifier stage;
- and
- dividing the potential between said power supply rails substantially equally between said first plurality of switches.
2 more elements
An amplifier circuit comprising:
- a positive supply rail and a negative supply rail;
- a first plurality of switches stacked between said positive and negative supply rails, a biasing string comprising a plurality of RC circuits stacked between said positive and negative supply rails, one of said switches receiving an external control signal to control the conduction state thereof, another of said switches being arranged as a current source;
- a second plurality of switches stacked between said positive and negative supply rails, the conduction state thereof being controlled by the conduction state of said first plurality of switches;
- and
- a feedback line from said second plurality of switches to said first plurality of switches to bias said first plurality of switches with said second plurality of switches;
- wherein said first plurality of switches comprises a first, second, third and fourth switch arranged in a series stacked relationship between said positive and negative supply rails, said first switch receiving said control signal to control the conduction state thereof and coupled to said positive supply rail, and said fourth switch configured to operate as a current source wherein the conduction state thereof is controlled by said negative supply rail, said switches defining a first node between said first and second switch, a second node between said second and third switch, and a third node between said third and fourth switch;
- said biasing string comprising a first, second, third and fourth parallel arrangement of said RC circuits arranged in a series stacked relationship between said positive and negative supply rails, said RC circuits dividing the potential between said positive and negative supply rails and defining a fifth node between said first and second RC circuits and a sixth node between said third and fourth RC circuits, the potential at said fifth node controlling the conduction state of said second switch, the potential at said sixth node controlling the conduction state of said third switch.
4 more elements
Dependencies are inferred from the claim text.