APPARATUS AND METHODS FOR CHOPPING RIPPLE REDUCTION IN AMPLIFIERS

摘要

Apparatus and methods for digitally-assisted feedback offset correction are provided herein. In certain configurations, an amplifier includes amplification circuitry for providing amplification to an input signal and chopping circuitry for compensating for an input offset voltage of the amplifier. Additionally, the amplifier further includes a digitally-assisted feedback offset correction circuit, which includes a chopping ripple detection circuit, a feedback-path chopping circuit, a digital correction control circuit, and an offset correction circuit. The chopping ripple detection circuit generates a detected ripple signal based on detecting an output ripple of the amplifier. Additionally, the feedback-path chopping circuit demodulates the detected ripple signal using the amplifier's chopping clock signal. The digital correction control circuit receives the demodulated ripple signal, which the digital correction control circuit uses to control a value of a digital offset control signal that controls an amount of input offset correction provided by the offset correction circuit.

主权项

1. An amplifier comprising:
amplification circuitry configured to generate an output signal based on amplifying a differential input voltage signal; chopping circuitry configured to provide chopping to the differential input voltage signal; and a feedback offset correction circuit comprising:
a chopping ripple detection circuit configured to generate a detected ripple signal based on detecting a chopping ripple of the amplifier associated with the chopping;a feedback-path chopping circuit configured to generate a demodulated ripple signal based on chopping the detected ripple signal;a digital correction control circuit configured to generate a digital correction control signal based on the demodulated ripple signal, wherein the digital correction control circuit is controlled by a control clock signal; andan offset correction circuit configured to correct for an input offset voltage of the amplification circuitry based on a value of the digital correction control signal.