Chopper amplifiers with tracking of multiple input offsets
AssigneeAnalog Devices, Inc.
InventorYoshinori Kusuda
Life of this patent
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Abstract
Chopper amplifiers with tracking of multiple input offsets are disclosed herein. In certain embodiments, a chopper amplifier includes chopper amplifier circuitry including an input chopping circuit, an amplification circuit, and an output chopping circuit electrically connected along a signal path. The amplification circuit includes two or more pairs of input transistors, from which a control circuit chooses a selected pair of input transistors to amplify an input signal. The chopper amplifier further incudes an offset correction circuit that senses the signal path to generate an input offset compensation signal for the amplification circuit. Furthermore, the offset correction circuit separately tracks an input offset of each of the two or more pairs of input transistors.
Claims20
A chopper amplifier with tracking of multiple input offsets, the chopper amplifier comprising:
- chopper amplifier circuitry comprising:
- an input chopping circuit configured to chop an input signal to generate a chopped input signal;
- an amplification circuit configured to amplify the chopped input signal to generate an amplified signal, wherein the amplification circuit comprises two or more pairs of input transistors that are selectable;
- an output chopping circuit configured to chop the amplified signal to generate a chopped output signal;
- and
- a control circuit configured to choose a selected pair of input transistors from the two or more pairs of input transistors, wherein the selected pair of input transistors is configured to amplify the chopped input signal;
- and
- an offset correction circuit configured to generate an input offset compensation signal for the chopper amplifier circuitry, wherein the offset correction circuit separately tracks an input offset of each of the two or more pairs of input transistors.
A method of amplification, the method comprising:
- chopping an input signal to generate a chopped input signal using an input chopping circuit;
- selecting a pair of input transistors from two or more pairs of input transistors of an amplification circuit using a control circuit;
- amplifying the chopped input signal to generate an amplified signal using the selected pair of input transistors;
- chopping the amplified signal to generate a chopped output signal using an output chopping circuit;
- and
- compensating the amplification circuit using an input offset compensation signal generated by an offset correction circuit, including separately tracking an input offset of each of the two or more pairs of input transistors.
A chopper amplifier comprising:
- a pair of input terminals;
- chopper amplifier circuitry comprising:
- an input chopping circuit including an input coupled to the pair of input terminals;
- an amplification circuit including an input coupled to an output of the input chopping circuit, wherein the amplification circuit comprises two or more pairs of input transistors that are selectable;
- an output chopping circuit including an input coupled to an output of the amplification circuit;
- and
- a control circuit configured to choose a selected pair of input transistors from the two or more pairs of input transistors to provide amplification;
- and
- an offset correction circuit configured to separately track an input offset of each of the two or more pairs of input transistors, and to generate an input offset compensation signal for compensating the amplification circuit.
Dependencies are inferred from the claim text.