Chopper amplifiers with high pass filter for suppressing chopping ripple
AssigneeLinear Technology Holding LLC
InventorsAlex R. Sloboda, Gregory L. DiSanto, Andrew K. Roberts
Life of this patent
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Abstract
Chopper amplifiers with high pass filters for suppressing chopping ripple are provided herein. In certain embodiments, a chopper amplifier includes an input chopping circuit, an amplification circuit, a low frequency content detection circuit, and an output chopping circuit electrically connected in a cascade. The low frequency content detection circuit operates in combination with a transconductance or other gain circuit as a high pass filter that filters input offset voltage and/or low frequency noise of the amplification circuit, thereby suppressing output chopping ripple from arising.
Claims20
A chopper amplifier with high pass filtering for suppressing chopping ripple, the chopper amplifier comprising:
- an input chopping circuit configured to generate a chopped differential input signal based on chopping a differential input signal;
- an amplification circuit configured to amplify the chopped differential input signal to provide an amplified differential signal at a differential output;
- an output chopping circuit electrically connected to the input chopping circuit by way of a differential signal path through the amplification circuit;
- and
- a high pass filter configured to provide high pass filtering to the amplified differential signal based on providing feedback from the differential output of the amplification circuit to the differential signal path along a feedback path, wherein the feedback path is configured to compensate for a DC offset of the amplification circuit.
A chopper amplifier with high pass filtering for suppressing chopping ripple, the chopper amplifier comprising:
- an input chopping circuit configured to generate a chopped differential input signal based on chopping a differential input signal;
- an amplification circuit configured to amplify the chopped differential input signal to provide an amplified differential signal at a differential output;
- an output chopping circuit electrically connected to the input chopping circuit by way of a differential signal path through the amplification circuit;
- and
- a high pass filter configured to provide high pass filtering to the amplified differential signal based on providing feedback from the differential output of the amplification circuit to the differential signal path;
- wherein the high pass filter includes an integration circuit configured to integrate the amplified differential signal to generate an integration voltage, and a transconductance circuit configured to amplify the integration voltage.
A method of amplification with suppressed chopping ripple, the method comprising:
- chopping a differential input signal with a chopping clock signal to generate a chopped differential input signal;
- amplifying the differential input signal to generate an amplified differential signal using an amplification circuit;
- chopping the amplified differential signal with the chopping clock signal to generate a chopped output signal;
- and
- high pass filtering the amplified differential signal by providing feedback from a differential output of the amplification circuit to a differential signal path through the amplification circuit, wherein high pass filtering the amplified differential signal comprises integrating the amplified differential signal to generate an integration voltage and amplifying the integration voltage to generate a feedback signal for the differential signal path.
Dependencies are inferred from the claim text.