US 10,256,777 B2 · Audio amplifiers

Abstract

Certain aspects of the present disclosure provide amplifiers. Certain aspects of the present disclosure provide methods and apparatus for protecting an such amplifiers, for example an audio amplifier, or a delta-sigma modulator from saturation. One example amplifier generally includes an output stage comprising a plurality of transistors; and a feedback network having an input coupled to an output of the output stage and comprising a plurality of integrators connected in series. At least one of the plurality of integrators generally includes an operational amplifier having an input and an output, a first resistive element coupled to the input of the operational amplifier, a capacitive element coupled between the input and the output of the operational amplifier; and a first switch coupled between the input and the output of the operational amplifier. For certain aspects, the amplifier may be a class-D amplifier or a direct digital feedback amplifier (DDFA).

Claims27

Dependent claims

An amplifier comprising:

an integrator comprising at least three integrator stages coupled in series;
and
control circuitry coupled to the integrator and configured to maintain a mode of a first or a last integrator stage of the at least three integrator stages and to modify a mode of at least one intermediate integrator stage of the at least three integrator stages while maintaining the mode of the first or the last integrator stage, wherein the control circuitry is configured to modify the mode of the at least one intermediate integrator stage by discharging a capacitive element in a feedback network of the at least one intermediate integrator stage.

Dependencies are inferred from the claim text.

Audio amplifiers

Life of this patent

Audio amplifiers

Life of this patent

Abstract

Claims27