Abstract: A transducer system has 1) a MEMS transducer configured to produce an analog output signal in response to an incident acoustic signal, and 2) a modulator apparatus. The modulator apparatus includes an analog modulator configured to receive the analog output signal and produce a first digital signal as a function of the analog output signal. In addition, the modulator apparatus also has a digital converter configured to receive the first digital signal and produce a second digital signal as a function of the first digital signal. The analog modulator has an analog order while, in a corresponding manner, the digital converter has a digital order. Preferably, the digital order is higher than the analog order.

Abstract: A transducer system has a transducer configured to receive an incident signal and produce an output signal as a function of the incident signal. As known in the art, the output signal has a ?3 dB point. The transducer system also has circuitry operatively coupled with the transducer. The circuitry includes an amplifier with an output configured to produce an amplified signal as a function of the output signal. In addition, the circuitry further has a positive feedback loop and a negative feedback loop that both are electrically coupled between the transducer and the amplifier. The positive feedback loop is configured to move the ?3 dB point in a first frequency direction. Conversely, the negative feedback loop is configured to move the ?3 dB point in a second frequency direction. Preferably, the first and second frequency directions are different.

Abstract: A transducer system has a transducer configured to receive an incident signal and produce an output signal as a function of the incident signal. As known in the art, the output signal has a ?3 dB point. The transducer system also has circuitry operatively coupled with the transducer. The circuitry includes an amplifier with an output configured to produce an amplified signal as a function of the output signal. In addition, the circuitry further has a positive feedback loop and a negative feedback loop that both are electrically coupled between the transducer and the amplifier. The positive feedback loop is configured to move the ?3 dB point in a first frequency direction. Conversely, the negative feedback loop is configured to move the ?3 dB point in a second frequency direction. Preferably, the first and second frequency directions are different.

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 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: In accordance with embodiments of the present disclosure, a merged filter-transconductor-upconverter for use in a wireless communication device is provided.

Abstract: In accordance with embodiments of the present disclosure, a merged filter-transconductor-upconverter for use in a wireless communication device is provided.

Abstract: An embodiment of an electronic system includes a digital audio amplifier having a continuous time modulator adapted to generate a difference signal between an audio bitstream and a feedback signal, and to perform a modulation process on the difference signal to generate an input pulse modulated signal, a class D output stage adapted to receive, quantize, and amplify the input pulse modulated signal to generate an output pulse modulated signal, and a feedback path adapted to provide the output pulse modulated signal as the feedback signal to the continuous time modulator. Another embodiment includes a class AB output stage adapted to receive and amplify an input digital audio signal to generate an analog output signal, and circuitry adapted to enable the digital audio amplifier to be configured to enable the class AB output stage and to disable the class D output stage.

Abstract: An embodiment of an electronic system includes a digital audio amplifier having a continuous time modulator adapted to generate a difference signal between an audio bitstream and a feedback signal, and to perform a modulation process on the difference signal to generate an input pulse modulated signal, a class D output stage adapted to receive, quantize, and amplify the input pulse modulated signal to generate an output pulse modulated signal, and a feedback path adapted to provide the output pulse modulated signal as the feedback signal to the continuous time modulator. Another embodiment includes a class AB output stage adapted to receive and amplify an input digital audio signal to generate an analog output signal, and circuitry adapted to enable the digital audio amplifier to be configured to enable the class AB output stage and to disable the class D output stage.

Abstract: A multi-mode analog-to-digital converter includes a delta-sigma analog-to-digital converter circuit configured to receive the analog input and produce a digital bit-stream associated therewith, the delta-sigma analog-to-digital converter including at least one integrator configured to reset to an initial state in response to a reset signal A digital filter circuit is configured to receive the digital bit-stream and produce two filtered outputs derived from the digital bit-stream. During one mode (e.g., a DC mode) the delta-sigma analog-to-digital converter circuit is configured to receive the reset signal and produce the digital bit-stream for a predetermined number of clock cycles, and the digital output corresponds to the first filtered output. In another mode (e.g., an AC mode), the delta-sigma analog-to-digital converter is configured to continuously produce the bit-stream, and the digital output corresponds to the second filtered output.

Abstract: A multi-mode analog-to-digital converter includes a delta-sigma analog-to-digital converter circuit configured to receive the analog input and produce a digital bit-stream associated therewith, the delta-sigma analog-to-digital converter including at least one integrator configured to reset to an initial state in response to a reset signal A digital filter circuit is configured to receive the digital bit-stream and produce two filtered outputs derived from the digital bit-stream. During one mode (e.g., a DC mode) the delta-sigma analog-to-digital converter circuit is configured to receive the reset signal and produce the digital bit-stream for a predetermined number of clock cycles, and the digital output corresponds to the first filtered output. In another mode (e.g., an AC mode), the delta-sigma analog-to-digital converter is configured to continuously produce the bit-stream, and the digital output corresponds to the second filtered output.

Abstract: A method and apparatus are provided for operating a feedback network (300, 400). The method and apparatus operate to combine (240) a feedback signal (IF) and an incoming signal (VIN) to generate an adjusted signal (IADJ) at an input node of an amplifier element (110); amplifying the amplifier input signal in the amplifier element to produce an amplifier output signal (VOUT) at an output node of the amplifier element; processing the amplifier output signal according to a feedback operation (230) to generate the feedback signal (IF); and providing an assist current (350, 450, IASSIST) to the output node of the amplifier element, separate from an output current provided by the amplifier element.