Chopped auto-zeroed ping-pong amplifier and related apparatus, system, and method
Patent 7834685 Issued on November 16, 2010. Estimated Expiration Date: October 15, 2028. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
An apparatus includes a plurality of amplifier stages configured to receive an input voltage and generate an amplified output current. Each amplifier stage includes a transconductance stage configured to receive the input voltage and generate a first intermediate output current. Each amplifier stage also includes an auto-zeroing loop configured to generate a second intermediate output current that at least partially corrects for an offset of the transconductance stage, where the auto-zeroing loop operates at a first frequency. Each amplifier stage further includes chopping circuitry configured to reverse a polarity of the input voltage and a polarity of the amplified output current at a second frequency, where the second frequency is less than the first frequency. Each amplifier stage is configured to operate in auto-zeroing and amplification phases. At least one amplifier stage operates in the auto-zeroing phase when at least one other amplifier stage operates in the amplification phase.
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