Abstract: A high-efficiency tracking power supply featuring a network of switched capacitors and an active noise shaping unit for reducing non-linearity and controlling the noise spectrum. Several variations of a non-inductive switched-capacitor tracking power-supply are presented, which are well-suited to integrated-circuit implementation and battery operation, and which provide an efficient power supply for the output stage over a wide range of voltages that can exceed the voltage limits of the main power source. The output of the tracking power-supply can be fed into an analog linear voltage regulator, or can be used as a Multi-Level Quantizer for generating the output directly. Some simple switching strategies are disclosed which offer power efficiencies in excess of 90%.

Abstract: A voice signal processing system with multiple parallel control paths, each of which address different problems, such as the high peak-to-RMS signal ratios characteristic of speech, wide variations in RMS speech levels, and high background noise levels. Different families of input-output control curves are used simultaneously to achieve efficient peak limiting and dynamic range compression as well as low-level dynamic expansion to prevent excessive amplification of background noise. In addition, a delay in the audio path relative to the control path makes it possible to employ an effective look-ahead in the control path, with FIR filtering smoothing-matched to the look-ahead. Digital domain peak interpolators are used for estimating the peaks of the input signal in the continuous time domain.

Abstract: A high-efficiency tracking power supply feating a network of switched capacitors and an active noise shaping unit for reducing non-linearity and controlling the noise spectrum. Several variations of an non-inductive switched-capacitor tracking power-supply are presented whch are well-suited to integrated-circuit implementation and battery operation, and which provide ani efficient power supply for the output stage over a wide range of volages that can exceed the votage limits of the main power source, The output of tile tracking power-supply can be fed into an analog linear voltage regulator, or can be used as a Multi-Level Quantizer for generating the output directly. Some simple switching strategies are disclosed which offer power efficiencies in excess of 90%.

Abstract: A high-efficiency audio power amplifier featuring a tracking power-supply and an active noise shaping unit for reducing non-linearly and audible noise. Several variations of an non-inductive switched-capacitor tracking power-supply are presented, which are well-suited to integrated-circuit implementation and battery operation, and which provide an efficient power supply for the output stage over a wide range of voltages that can exceed the voltage limits of the main power source. The output of the tracking power-supply can be fed into an analog power stage, or can be used as a Multi-Level Quantizer for generating the output directly. A feedback and noise shaping allows the use of low-cost components while relaxing design constraints. Some simple switching strategies are disclosed which offer power efficiencies in excess of 80%.

Abstract: An apparatus for conveying to a listener a pseudo low frequency psycho-acoustic sensation (Pseudo-LFPS) of a sound signal, including: frequency unit capable of deriving from the sound signal high frequency signal and low frequency signal (LF signal) that extends over a low frequency range of interest. Harmonics generator coupled to the frequency generator and being capable of generating, for each fundamental frequency within the low frequency range of interest, a residue harmonic signal having a sequence of harmonics. The sequence of harmonics, generated with respect to each fundamental frequency contains a first group of harmonics that includes at least three consecutive harmonics from among a primary set of harmonics of the fundamental frequency. Loudness generator coupled to the harmonics generator and being capable of bringing the loudness of the residue harmonic signal to match the loudness of the low frequency signal.