Silicon Laboratories Inc.

Cirrus Logic Inc.

Mark May

Eric B Smith

Vamsikrishna Parupalli

Steve Hanawalt

John L Melanson

Eric Jerome King

Xiaofan Fei

Dan Bernard Kasha

Xin Zhao

Russell Croman

Junsong Li

Zhong You

Carlos Jesus Briseno-Vidrios

Saurabh Singh

Scott Thomas Haban

Navin Harwalkar

Jun Yan

Mengde Wang

Ramya Balasundaram

Ken A Strickland

Mike R May

Tim Stroud

A downhole intelligent Circulating Sub controller detects the difference between rotary drilling and sliding drilling, responds appropriately and quickly to multiple changes between rotary drilling and sliding drilling that may occur several times each stand of pipe. Additional controls prevent actuation of the Circulating Sub at inappropriate times. In one embodiment, a separate modular control sub is disclosed that may be utilized with and/or removably secured to a Circulating Sub and/or other types of downhole tools.

Intelligent circulating sub for rotary/sliding drilling system and method

An electronic motor control system provides selectable linear and pulse-width modulated (PWM) operation without generating cross-over distortion. The system includes an output stage that has a pair of push-pull drivers each coupled to a terminal of the motor. The electronic motor control system also includes a pulse-width modulated (PWM) driver for providing pulse-width modulated drive signals to an input of the output stage when the pulse-width modulated mode is selected and a linear amplifier stage that provides a linear analog signal to the input of the output stage in linear mode, so that both drivers are operated to supply the current to the motor. In pulse-width modulated mode, a driver is selected for PWM operation, while the other driver is operated to supply a fixed voltage. A feedback control loop senses motor current and provides outputs to the pulse-width modulator and the linear amplifier stage.

Cross-over distortionless pulse-width modulated (PWM)/linear motor control system

A single-inductor multiple output (SIMO) switched-power DC-DC converter for a class-D amplifier provides outputs that are symmetric about a common-mode input voltage of the amplifier, while remaining asymmetric about a return terminal of the amplifier and switching converter. The DC-DC converter includes an inductive element, a switching circuit that energizes the inductive element from an input source, and a control circuit that controls the switching circuit. The control circuit may have multiple switching modes, and in one of the multiple switching modes, the switching circuit may couple the inductive element between outputs of the converter so that stored energy produces a differential change between the voltages of the outputs. The control circuit may implement a first control loop that maintains a common mode voltage of the pair of outputs at a predetermined voltage independent of the individual voltages of the pair of outputs.

Single-inductor multiple output (SIMO) switching power supply having offset common-mode voltage for operating a class-d audio amplifier

A system may include an output stage for driving a load at an output of the output stage, a pulse-width modulation mode path configured to pre-drive the output stage in a first mode of operation, a linear mode path configured to pre-drive the output stage in a second mode of operation and a loop filter coupled at its input to the output of the output stage and coupled at its output to both of the pulse-width modulation mode path and the linear mode path. The pulse-width modulation mode path and the linear mode path may be configured such that a first transfer function between the output of the loop filter and the output of the output stage is substantially equivalent to a second transfer function between the output of the loop filter and the output of the output stage.

Closed loop control in a camera module

A system may include a first capacitor, a first switched-mode power supply configured to deliver energy from a power source to the first capacitor at an output load of the first switched-mode power supply, a second capacitor having a capacitance larger than the first capacitor, a second switched-mode power supply configured to deliver energy from the power source or a second power source to the second capacitor and one or more switching elements coupled between the first capacitor and the second capacitor. The system may operate in a plurality of modes, including a first mode in which the first switched-mode power supply transfers energy to the first capacitor and the second capacitor, a second mode in which the second capacitor transfers energy to the first capacitor, and a third mode in which first switched-mode power supply transfers energy to the first capacitor and the second capacitor and the second switched-mode power supply transfers energy to the first capacitor and the second capacitor.

Switched-mode power supply with energy storage

An apparatus includes an input terminal to receive a radio frequency (RF) signal and to communicate the RF signal to a low noise amplifier (LNA) via an input signal path, and a capacitor attenuator coupled to the input terminal to attenuate the RF signal by a controllable amount and having a first portion controllable to include a used part configured on the input signal path and an unused part coupled between the input signal path and an AC reference node, and a second portion coupled between the LNA and the AC reference node.

Radio receiver having enhanced automatic gain control circuitry

In an embodiment, an apparatus includes a component of a receiver path to receive and process an incoming signal. At least one element of the component is controllable based on a DC output of the component, to compensate for a second order intermodulation product of the apparatus. As one example, the component is a differential amplifier including a first transistor and a second transistor.

Reducing second order distortion in an amplifier

In an embodiment, an apparatus includes a first signal path to receive and process a radio frequency (RF) signal of a first band and which has a first programmable digitizer to convert the RF signal of the first band into a digitized signal without downconversion. In addition, the apparatus further includes a second signal path to receive and process an RF signal of a second band, where at least portions of one or more of the paths may be shared during operation in the different bands.

Efficient dual channel conversion in a multi-band radio receiver

A radio receiver and method of operating the same are disclosed. In one embodiment, the radio receiver may include a RF receive path configured to convey a first radio signal within a first band to a radio tuning circuit. The RF receive path may be controllable using a first AGC circuit. The radio receiver may also include a loop-through path configured to convey a second radio signal within a second band between an input and an output of the radio receiver. The second band may be different from the first band. The loop-through path may be controllable using a second AGC circuit.

Receiver chip with multiple independent loop-through paths

A circuit includes an input terminal for receiving a radio frequency (RF) signal and a noise mitigation circuit coupled to the input terminal. The noise mitigation circuit is configured to detect a low-frequency noise signature in the RF signal and to automatically adjust an attenuation network to filter low-frequency noise from the RF signal in response to detecting the low-frequency noise signature.

Growing community of inventors

Austin, TX, United States of America

Mark May