Reduced-power dissipation for circuits handling differential pseudo-differential signals
AssigneeAnalog Devices, Inc.
InventorDaniel Rey-Losada
Life of this patent
Estimating the term…
Abstract
In an example, a differential amplifier is disclosed that is configured to realize low noise with decreased overall system current. The differential amplifier may include a first amplifier stage and a second amplifier stage arranged in series, wherein a pull-up current iH flowing as a single bias current iB=iH flows into the first stage. A single pull-down current iT sources to ground from the second stage, wherein iH=iT=iB substantially. In certain embodiments, the transconductance of the second stage may be increased by providing two transconductors coupled at their base nodes.
Claims23
A two-branch multi-stage amplifier circuit comprising:
- a first stage, comprising a first-branch transconductance and a second-branch transconductance electrically coupled to the first-branch transconductance;
- wherein the electrical coupling is disposed so that a current iH flowing into the first-branch transconductance as a bias current iB1, where iB1=iH, is provided substantially to the second-branch transconductance as a bias current iB2=iB1;
- and
- a second stage comprising a first second stage branch and a second second stage branch, wherein current flowing into the first second stage branch is not provided to the second second stage branch.
An integrated circuit comprising:
- a semiconductor die comprising a multi-stage amplifier having a first stage with a first-branch transconductance and a second-branch transconductance electrically coupled to the first-branch transconductance;
- wherein the electrical coupling is disposed so that a current iH flowing into the first-branch transconductance as a bias current iB1, where iB1=iH, is provided substantially to the second-branch transconductance as a bias current iB2=iB1;
- and
- a second stage comprising a first second stage branch and a second second stage branch, wherein current flowing into the first second stage branch is not provided to the second second stage branch.
An electronic system comprising:
- a signal source;
- a signal load;
- an input-stage amplifier electrically coupled to the signal source and configured to amplify the signal source, the input-stage amplifier comprising a first-branch transconductance and a second-branch transconductance electrically coupled to the first-branch transconductance, wherein the electrical coupling is disposed so that a current iH flowing into the first-branch transconductance as a bias current iB1, where iB1=iH, is provided substantially to the second-branch transconductance as a bias current iB2=iB1;
- and
- an output stage configured to provide the amplified signal to the signal load, having a first branch and a second branch, and having a positive supply voltage and a negative supply voltage, wherein the positive supply voltage and negative supply voltage are shared between the input-stage amplifier and the output stage, and wherein current flowing into the first branch of the output stage is not provided substantially to the second branch of the output stage.
Dependencies are inferred from the claim text.