SYSTEMS AND METHODS FOR GAIN CALIBRATION OF AN AUDIO SIGNAL PATH

摘要

A signal path may operate in one of a plurality of gain modes such that for each gain mode, the product of a digital gain and an analog signal gain of the signal path associated with the particular gain mode are approximately equal to a fixed path gain. During each of one or more calibration phases, a calibration system may measure analog signals at a plurality of nodes of the first path portion, calculate an actual analog gain associated with the gain mode based on the analog signals measured at the plurality of nodes, calculate an error between the fixed path gain and a mathematical product of the actual analog gain associated with the gain mode and the digital gain associated with the gain mode, and modify at least one of the digital gain and the analog gain associated with the gain mode in conformity with the error.

主权项

1. An integrated circuit, comprising:
a signal path comprising:
a first path portion comprising an amplifier having an audio input for receiving an analog input signal, an audio output for providing an output signal, and an analog gain selected from a plurality of analog gains in accordance with a gain mode, and configured to generate the output signal based on the analog input signal and in conformity with the analog gain; anda second path portion having a digital gain selected from a plurality of digital gains in accordance with the gain mode and configured to convert a digital audio input signal into the analog input signal in conformity with the digital gain;wherein the gain mode is selected from a plurality of gain modes such that for each particular gain mode of the plurality of gain modes, the product of the digital gain associated with the particular gain mode and the analog signal gain associated with the particular gain mode are approximately equal to a fixed path gain; and a calibration system configured to, during each of one or more calibration phases of the signal path, for each of one or more of the gain modes:
measure analog signals at a plurality of nodes of the first path portion;calculate an actual analog gain associated with the gain mode based on the analog signals measured at the plurality of nodes;calculate an error between the fixed path gain and a mathematical product of the actual analog gain associated with the gain mode and the digital gain associated with the gain mode; andmodify at least one of the digital gain and the analog gain associated with the gain mode in conformity with the error.