Hilight Semiconductor Limited

Nxp B.v.

Koninklijke Philips Corporation N.v.

Other

Secretary of State for Defence in Her Majesty's Government of the United

William Redman-White

Dominique Coue

Colin Whitfield

Simon Derek Bramwell

Derek John Hutchins

George James Brocklehurst

Frank Leong

Jan Van Sinderen

Sudhir Aggarwal

Carl Carley

Patrick Etienne Richard

Christian Rookes

Frank Harald Erich Ho Chung Leong

Jan Sinderen

Systems and methods for controlling laser modulation in burst communications. In a start-up phase, a drive circuitry sequentially applies first and second drive currents to a laser diode such that it produces a first and second optical output, respectively. A compensating current source coupled to the laser diode provides a current related to the first and second drive currents to maintain a combined current flowing through an impedance connected to the laser diode at a substantially constant level during the start-up phase. An optical sensor measures the first and second optical outputs, and a controller uses values of the first and second drive currents, the outputs from the optical sensor, and at least one supplied input value to provide control values for the drive circuitry for controlling operating current of the laser diode during a subsequent operating phase, wherein information is transmitted in at least one burst.

Method and system for controlling laser modulation

A construction and configuration for the receiving function of a high speed optical communication system with reduced manufacturing cost and improved performance. In an aspect, mounting the cover and lens provides a self-alignment behaviour that advantageously positions the cover and the lens to be in the optimum position for the photodiode. An assembly of electronic components receives data using an optical fibre. In one aspect, the assembly includes a photodiode, an amplifier coupled to the photodiode, and a printed circuit board on which the photodiode and amplifier are physically mounted, The printed circuit board has areas of a first material to which components may be attached using a fixing agent, and areas of a second material to which components will not attach using the fixing agent. Conductive bond wires are configured to directly couple the amplifier and the photodiode to conductive traces on an opposite side of the printed circuit board. A cover is configured to cover the amplifier and the photodiode, and is physically attached to the printed circuit board to provide mechanical rigidity around the photodiode and the amplifier. The cover has an optically transparent aperture containing a lens configured to focus modulated light signals from a fibre onto the photodiode. The printed circuit board has areas of a first material and second material configured to fix a location of the cover by use of the fixing agent to align the lens to focus the light signals from the fibre onto the photodiode.

Opto-electronic assembly

A system for transmitting a sequence of at least two data bursts in a fibre optical communications system includes: selection circuitry configured to select one of a data input value, a logical high value or a logical low value such that the selection circuitry selects the data input value during a data transmission period during a defined burst period and selects one of the logical high value and the logical low value during an extension time period during the defined burst period and immediately following the data transmission period, such that for the sequence of at least two bursts, at least one burst has a logical low value extension period and at least one burst has a logical high value extension period; drive circuitry configured to apply a current to a laser diode, the current corresponding to the value selected by the selection circuitry during the defined burst period or a zero value otherwise, the current being such that the laser diode is configured to provide an optical output; an optical sensor module configured to provide a sensor module output corresponding to the optical output of the laser diode; wherein the sensor module output is configured to provide an electrical output proportional to the laser diode's optical output corresponding to the logical high value and the logical low value in the sequence of at least two bursts, and further configured to provide an output corresponding to an average value of the sensor module output during only the data transmission period during the sequence of bursts; and a controller configured to receive values regarding desired minimum and maximum optical output power levels of the laser diode and to receive the electrical output from the optical sensor module proportional to the optical output power level corresponding to the logical high and the logical low values, and to receive the output corresponding to the average value of the sensor module output during only the data transmission period during the sequence of bursts; wherein the controller is configured to use the received information to provide control values for the drive circuitry.

Laser power controller

A system for controlling an optical intensity and modulation of an optical data transmitter which includes current driver circuitry configured to provide a drive current to a laser diode wherein said current comprises a fixed component and a modulated component, said modulated component having a magnitude related to an input data stream. The monitor circuitry contains a photodiode and a first transimpedance amplifier coupled to said photodiode, said monitor circuitry configured to provide an output signal related to an optical intensity of said laser diode. The system further includes replica monitor circuitry containing a replica capacitor with a replica capacitance and a second transimpedance amplifier configured to be substantially identical in construction to said first transimpedance amplifier, said second transimpedance amplifier coupled to said replica capacitor. The system further includes replica capacitance control circuitry configured to control said replica capacitance of said replica capacitor to match a capacitance associated with said photodiode.

Method for control of optical intensity and extinction ratio of laser modulation in an optical transmitter

A system comprising drive circuitry configured to apply in a start-up phase a first drive current and then a second different drive current to a laser diode, the first drive current and second drive current being such that the laser diode is configured to provide a first optical output and a second optical output respectively. The system further comprising an optical sensor configured to provide a first sensor output corresponding to the first optical output of the laser diode and a second sensor output corresponding to the second optical output. The system further comprises a controller configured to use a value of the first drive current, a value of the second drive current, the first sensor output, the second sensor output and at least one supplied input value to provide control values for the drive circuitry to control an operating current of the laser diode, wherein the system is arranged to be used in a communication system wherein information is transmitted in at least one burst.

A system is described for maintaining an inductive-capacitive (LC) network at resonance while the excitation frequency may be varied between a number of discrete frequencies at desired instants controlled by a modulation input, while taking into account component parameter errors due environmental and ageing as well as manufacturing tolerances. Control of the resonance while the excitation frequency changes permits the transmission of frequency modulation (FM) or frequency shift keying (FSK) information through an inductively coupled power transfer system.

Electronic tuning system

A system for controlling an optical data transmitter includes control circuitry comprising a voltage controlled current source configured to generate a reference current configured to generate at least two output currents whose magnitudes are in a fixed ratio wherein at least one of said output currents is used by said control circuitry to control current driver circuitry, a first plurality of serially coupled resistors, a first plurality of switches, a second plurality of serially coupled resistors, a second plurality of switches, and a look-up-table configured to control the first plurality of switches and the second plurality of switches based on an input to control a ratio.

Method for generating reference currents in proportion to enable control of average power and extinction ratio of laser modulation in an optical transmitter

A laser power controller employs: selection circuitry configured to select one of a data input value, a logical high value or a logical low value such that the selection circuitry selects the data input value during a data transmission period during a defined burst period and selects one of the logical high value and the logical low value during an extension time period during the defined burst period and immediately following the data transmission period; drive circuitry configured to apply, to a laser diode, a current corresponding to the value selected by the selection circuitry during the defined burst period or a zero value otherwise, the current being such that the laser diode is configured to provide an optical output; an optical sensor module configured to provide a sensor module output corresponding to the optical output of the laser diode, and configured to provide an electrical output proportional to the laser diode's optical output corresponding to the logical high value or the logical low value; and a controller configured to receive desired values regarding minimum and maximum optical output power levels of the laser diode and to receive the electrical output from the optical sensor module proportional to the optical output power level corresponding to the logical high and the logical low values; the controller being configured to use the received information to provide control values for the drive circuitry.

A system is provided that can automatically adjust a tuned circuit to resonate at the frequency of an applied excitation signal. The error in the resonant frequency of the tuned circuit is determined in real time from signals derived from within the network. The system permits the use of a time varying excitation frequency in a high Q circuit, including modulation conveying information. The tuning information may be stored in a memory and used to set the tuning instantaneously in order to maintain resonance when the excitation frequency changes abruptly, for example when frequency shift keying is used.

A trans-impedance amplifier arrangement has an input configured to receive an output from a photo-detector, a current monitoring circuit configured in use to provide a current monitor signal dependent on a current through the photo-detector, and an output configured to output said current monitor signal to a control module, said output further configured to receive control information from said control module. A control module is configured to receive the current monitor signal and to provide the control information.

Trans-impedance amplifier arrangement and control module

In accordance with one or more example embodiments, wireless communications are facilitated based on user-motion. A portable motion-sensing circuit, carried by a user, indicates that motion is sensed in response to detecting whether the user has been moving for a predetermined period of time. A communication circuit operates in active mode and inactive modes respectively consuming higher and lower power, permits or inhibits access authentication communications in the active and inactive modes, and operates in the active mode in response to the motion being sensed at the motion-sensing circuit.

Wireless communications circuit

A sensing circuit () for sensing the content of a memory cell (), wherein the sensing circuit comprises a sense node () connectable to the memory cell () so that a signal indicative of the content of the memory cell () is providable to the sense node (). The sensing circuit () further comprises a logic gate () having a first input, a second input and an output, wherein a reference signal () is providable to the first input and wherein the sense node () is coupled to the second input. The sensing circuit () further comprises a feedback loop () for coupling the output of the logic gate () to the second input of the logic gate () so that, during sensing the content of the memory cell (), an electrical potential at the sense node () is used to make a decision but after a result is obtained, the memory and sense amplifier combination are configured so that the result is held indefinitely and so that no static current continues to flow.

Circuit for sensing the content of a semiconductor memory cell

The present invention relates to a double data rate interface and method for use between a processor and random access memory, comprising a delay line including means for creating a delay in a data strobe signal from the random access memory, the delay line being arranged such that the delay in the data strobe signal is equal to the sum of set-up time and data bus rise time. The interface of includes the delay line comprising the delay locked loop which in turn comprises a ring oscillator. The ring oscillator includes a buffer and a Vernier delay.

Double data rate interface

A direct conversion receiver includes a detector that provides a measure of bias offset that is caused by component mismatches in the direct conversion mixer, and a corrective network that reduces the bias offset based on this measure. The direct conversion mixer demodulates a radio-frequency (RF) input signal via mixing with a local-oscillator (LO) signal to provide a differential baseband output signal. A differential peak detector compares the peak signal value at each side of the mixer's differential output, and a differential integrator averages the difference between these peak signal values to provide the measure of bias offset. The corrective network adds a correction offset to each of the local oscillator local oscillator paths on each of the switching pairs that provide the differential output, but opposite to the local oscillator connections. By applying the correction offset to the opposing transistor in each pair, the difference in switching time between the pairs is reduced, and, correspondingly, the differential-mode leakage from the local oscillator to the RF input stage is reduced.

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Alton, United Kingdom

William Redman-White