Silicon Laboratories Inc.

St-ericsson Sa

International Business Machines Corporation

St-ericsson India Pvt. Ltd.

St-ericsson Pvt. Ltd.

Ramkishore Ganti

Srinath Sridharan

Caiyi Wang

Brian Douglas Green

Lysander Lim

Srihari Adireddy

Sanjeev Ranganathan

Aria Eshraghi

David R Welland

Russell Croman

Shyam Somayajula

Peter Vancorenland

Lionel Cimaz

Augusto Manuel Marques

Arnold J D'Souza

Weinan Gao

Patrick Guyard

A protection circuit protects a receiver from high-energy signals. In one exemplary embodiment, the protection circuit comprises a snapback transistor and a controller. The snapback transistor comprises a gate, a drain connected to an input of the receiver and a source connected to ground. The controller configured to connect the gate to a bias voltage to close the gate in a transmit mode, and to disconnect the gate from the bias voltage to open the gate in a receive mode. The snapback transistor is configured to enter into snapback responsive to a high energy signal at the drain to provide a current path from the drain to the source even when the gate is open and thus protect the receiver.

Isolation and protection circuit for a receiver in a wireless communication device

A multi-standard transceiver comprises a common balun, a controller, at least one first switch, and at least one second switch. The common balun comprises a primary coil and a secondary coil. The at least one first switch connects the primary coil of the balun to a first signal path associated with a first communication standard, or to a second signal path associated with a second communication standard responsive to a control signal provided by the controller. The at least one second switch connects the secondary coil of the balun to a first amplification path associated with the first communication standard, or to a second amplification path associated with the second communication standard responsive to a control signal provided by the controller. A common mixer is configured to provide upconverted signals to one of the signal paths depending on which communication standard has been selected.

Multi-standard transceiver architecture with common balun and mixer

Systems and methods for a low pin architecture to couple speakers with integrated circuits are disclosed herein. In an implementation, the low pin architecture facilitates in reducing the required pin interfaces to couple a low power speaker, a high power speaker, and earphone speakers with integrated circuits (ICs). For this, the high power speaker can be cross-coupled between the pin interfaces that are coupled to the low power speaker and the earphone speakers. These pin interfaces are driven by corresponding driver circuits. In said implementation, some of the driver circuits can be shared to drive multiple pin interfaces. These shared driver circuits include a combined cascode circuit having a first cascode circuit integrated with a second cascode circuit to reliably and selectively drive one or more of the pin interfaces.

Coupling of speakers with integrated circuit

In one embodiment, the present invention includes a transceiver coupled to a baseband processor to receive digital control information that includes both event and schedule information, and which stores the digital control information in a storage of the transceiver. The transceiver may then be operated according to the event and schedule information.

Digital interface and related event manager for integrated circuits

Systems and methods for generation of a low jitter clock signal for wireless circuits are disclosed. In an implementation, the system includes a wireless circuit powered by a first power supply and a low jitter clock (LJC) generator powered by a second power supply. The LJC generator provides at least one clock signal to the wireless circuit. The system further includes an LJC driver circuit including a clock buffer powered by the first power supply and a receive buffer powered by the second power supply.

Generation of a low jitter clock signal

An RF transmitter () includes a shared local oscillator circuit (), transmit path circuitry (), a divider (), and a lowpass filter (). The shared local oscillator circuit () generates a shared LO signal (). The transmit path circuitry () mixes a baseband signal () and an IF mixing signal () to provide an IF signal (), and converts the IF signal () to an RF transmit signal () at a desired frequency using an RF mixing signal received at a mixing input thereof. The divider () divides the shared LO signal () to provide an unfiltered RF mixing signal. The lowpass filter () has an input for receiving the unfiltered RF mixing signal, and an output coupled to the mixing input of the transmit path circuitry () for providing the RF mixing signal.

Local oscillator (LO) port linearization for communication system with ratiometric transmit path architecture

A technique includes selecting one out of a plurality of frequency bands and providing a voltage controlled oscillator to generate a mixing signal for the selected frequency band. The technique includes adjusting a frequency gain of the voltage controlled oscillator based on the selected frequency band.

Calibration of phase locked loop parameters based on static band information

An apparatus comprises a circuit having a power supply node and a linear regulator configured to provide a regulated voltage at the power supply node of the circuit. The apparatus further comprises a switching regulator configured to provide input power to the linear regulator from a power source such as a battery. In some implementations, the circuit is a transceiver circuit.

System with linear and switching regulator circuits

In one embodiment, the present invention includes a method for receiving at a transceiver from a baseband processor digital control information that includes both event and schedule information, storing the digital control information in a storage of the transceiver, and operating the transceiver according to the event and schedule information.

A transceiver system including a common receiver and transmitter oscillator. The transceiver system may include transmitter circuitry, receiver circuitry, and a first oscillator. The first oscillator may provide a transmit frequency to a mixer in the transmitter circuitry to generate a transmitter RF signal. Furthermore, the first oscillator may also provide the transmit frequency to a first stage mixer in the receiver circuitry to down-convert a receiver RF signal from a receive frequency to an intermediate frequency (IF). The receiver circuitry may include a second oscillator and a second stage mixer. The second oscillator may provide an IF frequency to the second stage mixer to down-convert receiver signals at IF to a lower frequency. The receiver circuitry may filter out transmitter RF feedthrough signals without using a SAW filter. The transmitter circuitry, the receiver circuitry, and the first oscillator may be included in a single IC.

Transceiver system with common receiver and transmitter oscillator

A bandpass delta sigma truncator receives a series of first multi-bit digital signals each having a number of data bits, a first number of sign bits and sign extending means for sign extending each of the first multi-bit digital signals to a second multi-bit digital signal having the same number of data bits as the number of data bits in the first multi-bit digital signals, and a second number of sign bits. The truncator outputs from a series of third multi-bit digital signals a series of fourth multi-bit digital signals each having a selected number of the most significant data bits of the third multi-bit digital signals, and a series of fifth multi-bit digital signals each having the remaining number of the least significant data bits of the third multi-bit digital signals.

Bandpass delta sigma truncator and method of truncating a multi-bit digital signal

A digital to analog converter which produces a non-return to zero output voltage. Two SIN DAC converters having return to zero (RZ) output voltages connected to provide a common NRZ output signal. The SIN DAC converters receive the digital signal and a delayed version of the digital signal. The reference sine voltage applied to each SIN DAC have a respective phase shift so that the outputs from each SIN DAC are phase shifted. The combined phase shifted output signals produce an NRZ signal with a reduced susceptibility to clock signal jitter, and which contain significantly less high frequency content than the RZ output signal from a SIN DAC.

Non-return-to-zero DAC using reference sine wave signals

A continuous time delta-sigma analog to digital converter is disclosed. A summing junction receives an input analog signal to be digitized and a feedback signal. A loop filter receives the combined signals from the summing junction, and a course analog to digital converter converts the combined signal to a multi-bit digital number. A sin DAC provides a feedback signal to the summing junction, by reconverting the multi-bit digital signal to an analog signal. The sin DAC produces a linear output signal having a reduced phase jitter, resulting in a lower noise floor for the multi-digital signal. The sin DAC may be an NRZ sin DAC which avoids stringent linearity requirements on the summing junction.

High performance delta sigma ADC using a feedback NRZ sin DAC

A circuit and method for initiating operation of a bandgap reference circuit. A start pulse circuit provides a start pulse when the bandgap circuit is powered up. A transistor receives the pulse as an input, and applies the pulse to a regenerative bandgap reference circuit. The bandgap reference circuit output voltage is forced above a normal output voltage, producing a feedback current through the bandgap reference circuit, providing a current level which exceeds the normal stable operating level and output voltage level range. When the pulse ceases, the regenerative bandgap reference circuit output voltage decreases to its normal stable value, and the regenerative bandgap reference circuit is placed in its normal stable operating state.

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Dripping Springs, TX, United States of America

Ramkishore Ganti