Qualcomm Incorporated

Quantenna Communications, Inc.

Koushik Krishnan

Rainer Gaethke

Faramarz Sabouri

Jafar Savoj

Shirin Chegeni

A charge pump and a differential phase locked loop incorporating the charge pump. The charge pump includes a differential charge pump and an auxiliary charge pump. The differential charge pump has differential inputs and primary and mirror outputs. The differential charge pump is responsive to a down signal at the differential inputs to provide a negative current at the primary output and a positive current at the mirror output, and further responsive to an up signal at the differential inputs to provide a positive current at the primary output and a negative current at the mirror output. The auxiliary charge pump has differential inputs and an auxiliary output coupled to the mirror output of the differential charge pump. The differential charge pump is responsive to the down signal at the differential inputs to provide a negative current at the auxiliary output, and responsive to the up signal at the differential inputs to provide a positive current at the auxiliary output.

Apparatus for linearizing a differential charge pump

A near-field communications (NFC) device includes an NFC antenna, a matching network coupled to the NFC antenna, and a transmitter coupled to the matching network. The transmitter applies a signal to the matching network and varies a frequency of the signal. A parameter is measured while varying the frequency of the signal. A peak value of the parameter is identified and compared to a threshold. A communication protocol is initiated in response to a determination that the peak value satisfies the threshold.

Carrier frequency variation for device detection in near-field communications

First and second NFC devices both seek to determine whether the other device is present and available for communication across an NFC channel. The first NFC device modulates a load in its transceiver. The second NFC device transmits a waveform. If the first NFC device detects the waveform while modulating its load, and if the second NFC device detects the load modulation while transmitting the waveform, then the two NFC devices initiate communication in accordance with a communication protocol.

Device detection using load modulation in near-field communications

A near-field communications (NFC) device includes an NFC antenna, a matching network coupled to the NFC antenna, and a transmitter coupled to the matching network. The transmitter applies a signal to the matching network and a capacitance of the matching network is varied. A parameter is measured while varying the capacitance of the matching network and while applying the signal. A peak value of the parameter is identified and compared to a threshold. A communication protocol is initiated in response to a determination that the peak value satisfies the threshold.

Circuit tuning for device detection in near-field communications

Methods and apparatus for a gray-coded phase rotating frequency divider. A phase selector is provided that includes two or more selectors, each selector configured to receive multiple clock phases and output a respective clock phase based on one or more selection bits that are part of a selection input, and a gray code generator configured to generate a gray coded output that forms the selection input so that when the gray coded output changes state only selection bits associated with a single selector change. A method includes grouping a plurality of clock phases into two or more groups, for each group, selecting a respective clock phase based on one or more selection bits that are part of a selection input, and generating a gray coded output that forms the selection input so that when the gray coded output changes state only selection bits associated with a single group change.

Methods and apparatus for a gray-coded phase rotating frequency divider

A method of calibrating oscillators is disclosed that includes searching, in an array storing an operational characteristic of the oscillator, for an index value that is associated with an output of the oscillator; determining that the output is within a predetermined accuracy as compared to a desired output; and generating the output based the index value. An apparatus for performing the method is also disclosed herein.

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San Jose, CA, United States of America

Koushik Krishnan