Qualcomm Incorporated

Wenchang Huang

Arash Mehrabi

Meysam Azin

Peter J Shah

Vijayakumar Dhanasekaran

Ramkumar Sivakumar

Weibo Hu

Certain aspects of the present disclosure generally relate to a sampling network of a switched-capacitor integrator and a clocking scheme associated therewith, which may be used in an analog-to-digital converter (ADC), for example. The integrator generally includes five sets of switches which allow for a decreased switching frequency (e.g., halved) at an input stage of the integrator compared to conventional double sampling networks. As a result, the input impedance of the integrator may be increased (e.g., doubled), resulting in lower power consumption and reduced strain on driving circuitry.

Sampling network and clocking scheme for a switched-capacitor integrator

An apparatus includes an operational amplifier and a plurality of capacitors coupled to an input terminal of the operational amplifier and configured to be selectively coupled to receive one of an input voltage signal and an output voltage signal of the operational amplifier.

Capacitive programmable gain amplifier

Devices and methods for analog to digital conversion are provided. The device can have a supply voltage coupled to a bootstrap circuit operable to provide a boosted voltage during a first period defined by a sample phase (Ps) signal and a hold phase (Ph) signal. The device can also have a sampling circuit having an input node and operable to sample an input signal supplied to the input node. The device can also have a switching circuit having a first switch and a second switch. The switching circuit can be coupled to the bootstrap circuit and to the sampling circuit. The switching circuit can be configured to isolate the input node from shorting currents to the supply voltage for a portion of the first period.

Low distortion sample and hold switch

An integrated DC blocking amplifier circuit, including: an operational amplifier configured in a differential amplifier; and at least first and second two-stage switched-capacitor circuits, each two stage switched-capacitor circuit including a first-stage circuit and a second-stage circuit, wherein the first two-stage switched capacitor circuit is connected to a positive side feedback path of the operational amplifier and the second two-stage switched capacitor circuit is connected to a negative side feedback path of the operational amplifier, wherein the first-stage circuit is switched at a relatively low switching frequency, while the second-stage circuit is switched at a relatively high switching frequency.

Multi-stage switched-capacitor DC blocking circuit for audio frontend

An amplifier with improved noise reduction is disclosed. In an exemplary embodiment, an apparatus includes at least one capacitor configured to receive an adjustable current and generate a corresponding ramp voltage configured to control coupling between a main amplifier output and a secondary amplifier output. The apparatus also includes at least one comparator configured to adjust the adjustable current to generate the ramp voltage with selected ramp-up or ramp-down voltage characteristics.

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Wenchang Huang