Abstract: Certain aspects of the present disclosure provide apparatus and techniques for segmenting a digital input signal for digital-to-analog conversion. For example, certain aspects provide a segmentation circuit for generating digital signal segments for a digital-to-analog converter. The segmentation circuit generally includes a modulo function logic circuit configured to generate a modulo output signal based on a digital input signal and a divisor input signal and a modulo range extension logic circuit configured to selectively direct the modulo output signal or the divisor input signal to an output of the segmentation circuit. In certain aspects, the output of the segmentation circuit may be used by the digital-to-analog converter to generate an analog signal based on the digital input signal.

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).

Abstract: Certain aspects of the present disclosure provide an amplifier for signal amplification. Certain aspects further describe methods and apparatus for applying overload protection for such amplifier. For example, one method generally includes detecting an overload condition of an amplifier based on a signal at a node of the amplifier, and controlling a parameter of an input signal of the amplifier such that the parameter of the input signal is maintained below a threshold based on the detection of the overload condition. The parameter of the input signal may include, for example, a voltage level or a duty cycle of the input signal.

Abstract: Certain aspects of the present disclosure provide methods and apparatus for dynamically managing the dead time between turning on output power stage transistors in amplifiers, such as audio amplifiers. One example method of operating an amplifier generally includes generating a drive signal based on an input signal; amplifying the drive signal by alternatively driving a first transistor and a second transistor with a time between deactivating the first transistor and activating the second transistor; and adjusting the time based on a parameter of the input signal or the drive signal, during the amplifying. For example, the parameter may include an amplitude of the input signal, a duty cycle of the drive signal, or a duty cycle of a modulated signal (e.g., a pulse-width modulated signal) generated based on the input signal. The input signal may be a digital audio input signal.

Abstract: Certain aspects of the present disclosure provide an amplifier for signal amplification. Certain aspects further describe methods and apparatus for applying overload protection for such amplifier. For example, one method generally includes detecting an overload condition of an amplifier based on a signal at a node of the amplifier, and controlling a parameter of an input signal of the amplifier such that the parameter of the input signal is maintained below a threshold based on the detection of the overload condition. The parameter of the input signal may include, for example, a voltage level or a duty cycle of the input signal.

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).

Abstract: A method and system which includes a minimally invasive, implantable device with a sensor configured for collecting electrical data associated with cardiac performance, a sensor configured for collecting mechanical data associated with cardiac performance, a sensor for collecting optical data associated with cardiac performance, a sensor for collecting biochemical data associated with cardiac performance, and a processor for deriving cardiac conditions and actuating an alarm upon identifying a cardiac event.

Abstract: A method and system which includes a minimally invasive, implantable device with a sensor configured for collecting electrical data associated with cardiac performance, a sensor configured for collecting mechanical data associated with cardiac performance, a sensor for collecting optical data associated with cardiac performance, a sensor for collecting biochemical data associated with cardiac performance, and a processor for deriving cardiac conditions and actuating an alarm upon identifying a cardiac event.