US 8,717,211 B2 · Adaptive gain adjustment system

Abstract

Techniques for adaptive gain adjustment in a signal processing path to achieve greater dynamic range. In an exemplary embodiment, a digital gain is applied to a digital input signal based on a detected level of the digital input signal. A corresponding analog gain is applied to the output of a digital-to-analog converter for converting the digital input signal to an analog signal, the product of the digital gain and the analog gain being kept constant. In an exemplary embodiment, a zero cross detector is employed to update the digital and analog gains only in the vicinity of zero crossings detected in the signal. In a further exemplary embodiment, a peak detector is employed to instantaneously adjust the digital and analog gains to avoid clipping in the signal path.

Claims32

Dependent claims

An apparatus for processing a digital input signal having a sampling frequency, the apparatus comprising:

an adaptive gain selection module for selecting a target gain setting based on a detected level of the digital input signal, a higher target gain setting being selected for a lower detected level;
a digital multiplier for to multiplying an upsampled version of the digital input signal with an instantaneous digital gain approaching the target gain setting to generate a digital output signal, the instantaneous digital gain updated upon detection of a zero cross in the upsampled version of the digital input signal;
and
an amplifier for amplifying an analog version of the digital output signal with an instantaneous analog gain inversely proportional to the instantaneous digital gain.

1 more element

Dependencies are inferred from the claim text.

Adaptive gain adjustment system

Life of this patent

Adaptive gain adjustment system

Life of this patent

Abstract

Claims32