Qualcomm Incorporated

Other

Brett Christopher Walker

Raghu Narayan Challa

Tao Li

Jeremy Darren Dunworth

Matthew Levi Severson

Paul E Peterzell

Inyup Kang

Gilbert Christopher Sih

Christian Holenstein

Song Shi

Arun Raghupathy

Kenneth Charles Barnett

Kevin Glenn Gard

Gurkanwal Singh Sahota

Todd Robert Sutton

Bo Sun

Troy L Stockstad

Seyfollah Seyfollahi Bazarjani

David J Maldonado

Mustafa Keskin

Puay Hoe See

Joseph Duncan

Michael Naone Farias

James Ian Jaffee

Iulian Mirea

David W Hansquine

Michael McGowan

Chi Fan Yung

Justin Philpott

Steven M Mollenkopf

Eric B Zeisel

Mukesh Bansal

Raymond Rosik

Zhiqing Zhang

Puay Hoe Andrew See

Peter C Gazzerro

Guang Zhang

Jong Jin Kim

Qadeer Khan

Muhammad Asim Muneer

Injup Kang

Techniques and apparatus for selecting a maximum input supply voltage from multiple input power supplies. An example maximum input supply selection circuit includes a parallel array of comparators and selection logic to select the maximum input supply voltage, supply present detectors, comparator settling logic including a warm-up delay timer to provide for comparator settling, and comparator enable logic for disabling all comparators and entering an ultra-low power mode.

Low power high speed maximum input supply selector

Certain aspects of the present disclosure provide methods and apparatus for level shifting an input signal ranging between certain voltage levels to generate an output signal ranging between other voltage levels with low power, high speed, and immunity to noise. One example level-shifting circuit generally includes a node for receiving an input signal ranging between a first voltage level and a second voltage level, a first circuit path coupled to the node and configured to level shift the input signal to generate an output signal ranging between a third voltage level and a fourth voltage level, a pulse generator coupled to the node and configured to generate a pulse based on a transition in the input signal between the first and second voltage levels, and a second circuit path connected in parallel with the first path and configured to temporarily short the first path based on the generated pulse.

Level shifter

Features and advantages of the present disclosure include a switching regulator and current measurement circuit. In one embodiment, a switching transistor in the switching regulator has a first voltage on a first terminal and a switching voltage on a second terminal. A current measurement circuit has first and second input terminals. A first switch couples the second terminal of the switching transistor to the first terminal of the current measurement circuit when the switching transistor is on, where the second input terminal of the current measurement circuit is coupled to the first terminal of the switching transistor and measurement(s) may be taken. When the switching transistor is off, the first and second input terminals of the current measurement circuit are coupled together, and measurements emulate zero current through the switching transistor.

Current measurments in switching regulators

A user device determines whether a device connected to its headset jack is an audio accessory device. If the device connected to the headset jack is an audio accessory, the user device connects one or more pins of the headset jack to an audio codec. If the device plugged into the headset jack is not an audio accessory device, the user device connects one or more pins of the headset jack to alternate circuitry. The user device then determines, through the alternate circuitry, an electrical operating parameter requirement of the accessory device, and provides, from the alternate circuitry, the required operating parameter to the accessory device through the headset jack. The alternate circuitry may include an adjustable voltage regulator and/or an adjustable current regulator and the required operating parameter may be one or more of a voltage supply and a current supply.

Electronics interface for device headset jack

Embodiments disclosed herein address the need for a single wire bus interface. In one aspect, a device communicates with a second device via a single wire bus using a driver for driving the bus with a write frame comprising a start symbol, a write indicator symbol, an address, and data symbols. In another aspect, the device receives one or more data symbols on the single wire bus during a read frame. In yet another aspect, a device communicates with a second device via a single wire bus using a receiver for receiving a frame on the single wire bus comprising a start symbol, a write indicator symbol, an address, and one or more data symbols, and a driver for driving return read data associated with the address when the write indicator identifies a write frame. Various other aspects are also presented. These aspects provide for communication on a single wire bus, which allows for a reduction in pins, pads, or inter-block connections between devices.

Single wire bus interface

Output circuits using pulse width modulation (PWM) and/or pulse density modulation (PDM) are described. In one aspect, a PWM output circuit includes a PWM modulator that operates based on a square wave signal instead of a sawtooth or triangular wave signal. In another aspect, a PDM output circuit includes a PDM modulator that uses variable reference voltages to reduce variations in switching frequency. In yet another aspect, a dual-mode output circuit supports both PWM and PDM and includes a pulse modulator and a class D amplifier. The pulse modulator performs PWM on an input signal if a PWM mode is selected and performs PDM on the input signal if a PDM mode is selected. The class D amplifier receives a driver signal from the pulse modulator and generates an output signal.

Output circuits with class D amplifier

A direct downconversion receiver architecture having a DC loop to remove DC offset from the signal components, a digital variable gain amplifier (DVGA) to provide a range of gains, an automatic gain control (AGC) loop to provide gain control for the DVGA and RF/analog circuitry, and a serial bus interface (SBI) unit to provide controls for the RF/analog circuitry via a serial bus. The DVGA may be advantageously designed and located as described herein. The operating mode of the VGA loop may be selected based on the operating mode of the DC loop, since these two loops interact with one another. The duration of time the DC loop is operated in an acquisition mode may be selected to be inversely proportional to the DC loop bandwidth in the acquisition mode. The controls for some or all of the RF/analog circuitry may be provided via the serial bus.

Direct conversion receiver architecture

In one embodiment, this disclosure describes a frequency synthesizer for use in a wireless communication device, or similar device that requires precision frequency synthesis but small amounts of noise. In particular, the frequency synthesizer may include a phase locked loop (PLL) and an integrated voltage controlled oscillator (VCO). The frequency synthesizer may implement one or more calibration techniques to quickly and precisely calibrate the VCO. In this manner, the analog gain of the VCO can be significantly reduced, which may improve performance of the wireless communication device. Also, the initial state of the PLL may be improved to reduce lock time of the PLL, which may enhance performance of the wireless communication device.

Calibration techniques for frequency synthesizers

A method for controlling the voltage of signals used to control power amplifiers is described. A first multiplexer and a second multiplexer are set to an enabling signal. The first multiplexer is on a first integrated circuit and the second multiplexer is on a second integrated circuit. A command is written to the first multiplexer to set the first multiplexer to one of a plurality of control signals used to control a power amplifier. A command is written to the second multiplexer to select one of the plurality of control signals that maps to the first multiplexer. The second integrated circuit is connected to a power supply.

Systems and methods for controlling the voltage of signals used to control power amplifiers

In one embodiment, this disclosure describes a frequency synthesizer for use in a wireless communication device, or similar device that requires precision frequency synthesis but small amounts of noise. In particular, the frequency synthesizer may include a phase locked loop (PLL) and an integrated voltage controlled oscillator (VCO). The frequency synthesizer may implement one or more amplitude calibration techniques prior to enabling the PLL. For example, an amplitude calibration unit may be used to selectively activate switched unit current sources within a tail current source of the VCO. In this manner, the amplitude the signal generated by the oscillator can be adjusted without requiring closed-loop amplitude monitoring or control.

Discrete amplitude calibration of oscillators in frequency synthesizers

Serial bus interface for direct conversion receiver

Growing community of inventors

San Diego, CA, United States of America

Brett Christopher Walker