Method for offset compensation of a switched-capacitor amplifier and switched capacitor amplifier arrangement
AssigneeAms AG
InventorVincenzo Leonardo
Life of this patent
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Abstract
A method for offset compensation of a switched-capacitor amplifier comprises a reset phase (φ1) and at least one working phase (φ2). An output voltage (Vout) of the amplifier (amp) is fed according to a damped feedback loop gain (AB(1)) to a first amplifier input (ain1) in the reset phase (φ1) as a function of an offset voltage (Voff). In the least one working phase (φ2), an offset of the amplifier (amp) is compensated as a function of the offset voltage (Voff) by superimposing the output voltage (Vout) onto an input voltage (Vin) of the amplifier (amp) according to a loop gain (AB(2)).
Claims11
A method for offset compensation of a switched-capacitor amplifier comprising:
- in a reset phase, feeding an output voltage of the amplifier according to a damped feedback loop gain to a first amplifier input as a function of an offset voltage;
- and
- in at least one working phase, compensating an offset of the amplifier as a function of the offset voltage by superimposing the output voltage on an input voltage of the amplifier according to a feedback loop gain,
- wherein the damped feedback loop gain is adjusted as a function of a quotient of resistance values using a voltage divider.
A method for offset compensation of a switched-capacitor amplifier comprising:
- in a reset phase, feeding an output voltage of the amplifier according to a damped feedback loop gain to a first amplifier input as a function of an offset voltage;
- and
- in at least one working phase, compensating an offset of the amplifier as a function of the offset voltage by superimposing the output voltage on an input voltage of the amplifier according to a feedback loop gain,
- wherein the offset voltage is buffered in the reset phase by a charge storage means and is connected in the at least one working phase to the input voltage for offset compensation, and
- wherein the feedback loop gain is adjusted as a function of a quotient of capacitance values of the charge storage means.
A switched-capacitor amplifier arrangement with an input and an output, comprising:
- an amplifier, having a first amplifier input coupled by an offset compensation device to the input, and a second amplifier input adapted to be supplied with an offset voltage, wherein the amplifier comprises an amplifier output that is connected to the output;
- and
- a feedback loop wherein the amplifier output is either electrically coupled to the offset compensation device by first switches via a damping member in a reset phase, or directly by second switches in at least one working phase,
- wherein the input is likewise electrically coupled by the second switches to the offset compensation device in the at least one working phase, and
- wherein the damping member comprises a voltage divider that is coupled by at least two of the first switches to the amplifier output and to the offset compensation device, and is configured to adjust a loop gain of the feedback loop.
A switched-capacitor amplifier arrangement with an input and an output, comprising:
- an amplifier, having a first amplifier input coupled by an offset compensation device to the input, and a second amplifier input adapted to be supplied with an offset voltage, wherein the amplifier comprises an amplifier output that is connected to the output;
- and
- a feedback loop wherein the amplifier output is either electrically coupled to the offset compensation device by first switches via a damping member in a reset phase, or directly by second switches in at least one working phase,
- wherein the input is likewise electrically coupled by the second switches to the offset compensation device in the at least one working phase,
- wherein the offset compensation device comprises a charge storage means, and
- wherein the charge storage means comprises a first and a second capacitor coupled to one another, whose facing electrodes are connected to the first amplifier input and whose electrodes facing away from one another are connected by the first switches to a reference potential.
Dependencies are inferred from the claim text.