Two-stage amplifier
AssigneeMicronas GmbH
InventorsUlrich Theus, Juergen Kessel
Life of this patent
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Abstract
A two-stage amplifier includes a first stage and a second stage that are DC-connected through a coupling capacitor Cp. A charge pump generates a bias voltage Vp that is applied across the coupling capacitor Cp leads to maintain the time average of the voltage across said coupling capacitor constant.
Claims19
A two-stage amplifier that provides a two-stage amplifier output signal, said two-stage amplifier comprising:
- a first amplifier stage that receives a first amplifier input signal, and provides a first amplifier output signal;
- a second amplifier stage that includes a second amplifier input lead, and provides the two-stage amplifier output signal;
- a coupling capacitor having a first lead and a second lead, wherein said first lead receives said first amplifier output signal, and said second lead is connected to said second amplifier input lead such that said coupling capacitor is connected in series between said first and second amplifier stages;
- and
- a charge pump that generates a bias voltage that is applied to said coupling capacitor via said first and second leads to maintain the time average of the voltage across said coupling capacitor constant, wherein
- said two-stage amplifier output signal is feedback and coupled to an input signal to provide said first amplifier input signal.
The two-stage amplifier of 1, wherein said first amplifier stage includes a transconductance amplifier.
A two-stage amplifier that provides a two-stage amplifier output signal, said two-stage amplifier comprising:
- a first amplifier stage that receives a first amplifier input signal, and provides a first amplifier output signal;
- a second amplifier stage that includes a second amplifier input lead, and provides the two-stage amplifier output signal;
- a coupling capacitor having a first lead and a second lead, wherein said first lead receives said first amplifier output signal, and said second lead is connected to said second amplifier input lead such that said coupling capacitor is connected in series between said first and second amplifier stages;
- a charge pump that generates a bias voltage that is applied to said coupling capacitor via said first and second leads to maintain the time average of the voltage across said coupling capacitor constant;
- and
- an integrated voltage source that provides a reference voltage to said charge pump;
- wherein said charge pump includes means for generating said bias voltage to maintain a fixed ratio between said reference voltage and said first amplifier input signal.
A two-stage amplifier that provides a two-stage amplifier output signal, said two-stage amplifier comprising:
- a first amplifier stage, comprising a transconductance amplifier, that receives a first amplifier input signal, and provides a first amplifier output signal;
- a second amplifier stage that includes a second amplifier input lead, and provides the two-stage amplifier output signal;
- a coupling capacitor having a first lead and a second lead, wherein said first lead receives said first amplifier output signal, and said second lead is connected to said second amplifier input lead such that said coupling capacitor is connected in series between said first and second amplifier stages;
- and
- a charge pump that generates a bias voltage that is applied to said coupling capacitor via said first and second leads to maintain the time average of the voltage across said coupling capacitor constant.
The two-stage amplifier of 12, comprising a compensation capacitor that is connected electrically in parallel to the input of said second amplifier stage.
Dependencies are inferred from the claim text.