Abstract: An analog-to-digital conversion (ADC) system includes a transconductance amplifier, loop filter, quantizer, logic circuit, and digital-to-analog converter (DAC). The transconductance amplifier is configured to generate a current signal in response to an audio signal. The loop filter is connected to the transconductance amplifier and configured to generate a filtered signal based on the current signal. The quantizer is configured to generate a digital representation of the filtered signal. The logic circuit is configured to generate control signals based on the digital representation. The DAC is coupled to the loop filter's and the transconductance amplifier's output. The DAC includes three-level unit elements, where each unit element is configured to provide one of two signal levels or no signal to the loop filter in response to control signals from the logic circuit. Such an ADC system may allow for a high dynamic range while maintaining low power consumption and low noise.

Abstract: An audio digital-to-analog converter (DAC) achieves high dynamic range with low power consumption using a segmented DAC, also referred to as a noise shaped splitter. The noise shaped splitter is dynamically reconfigured based on envelope detection that tracks the amplitude of an n-bit digital input signal to the segmented DAC. The amplitude of the n-bit digital input signal can be expressed as the magnitude of a numerical value corresponding to the n bits of the digital signal. Based on the amplitude of the digital input signal, certain segments of the segmented DAC are bypassed and the components of each bypassed segment are turned off, saving power and reducing noise, and achieving improved dynamic range along with lower power consumption.