Abstract: 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.

Abstract: 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.

Abstract: The present invention provides a master slave arrangement for providing communication between a master device and a slave device, the arrangement comprising: a first serial bus connecting said master device with an intermediate device and a second serial bus connecting said intermediate device with a slave device, said second serial bus comprising a data line, a clock line and one or more addressing lines, wherein said intermediate device i) interprets a request made by said master device; and (ii) sends a signal to said slave device over said one or more addressing lines to identify a memory location of said slave device to which said request is associated.

Abstract: An arrangement of a master device and a slave device, includes one or more physical memory means and a plurality of logical memory means, wherein one or more of the logical memory means are permanently accessible by the master device and one or more further logical memory means may be accessed by the master device in response to a pre-determined access code being received at a pre-determined memory location.

Abstract: The present invention provides a master slave arrangement for providing communication between a master device and a slave device, the arrangement comprising: a first serial bus connecting said master device with an intermediate device and a second serial bus connecting said intermediate device with a slave device, said second serial bus comprising a data line, a clock line and one or more addressing lines, wherein said intermediate device i) interprets a request made by said master device; and (ii) sends a signal to said slave device over said one or more addressing lines to identify a memory location of said slave device to which said request is associated.

Abstract: A laser diode is matched to a laser driver IC by a microwave stub to take advantage of radio frequency/microwave effects of electrical conductors on high frequency signals. The microwave stub is a piece of microwave transmission line with a characteristic impedance defined by its physical dimensions and its material. A transmission line having a distributed set of capacitors and inductors is tuned over a range of frequencies by changing its operating length/width. A capacitor short circuits the microwave stub to ground. The capacitor position along the microwave stub determines the microwave transmission line operating length (and hence frequency). Therefore, a matching network is tuned by changing the capacitor position along the microwave stub instead of using several different valued capacitors.

Abstract: In the context of matching a laser diode (154) with a laser driver IC (20), a microwave stub (166, 200, 202, 220, 222) is used in place of a conventional shunt resistor/capacitor network and takes advantage of radio frequency/microwave effects of electrical conductors on high frequency signals. The microwave stub (166, 200, 202, 220, 222) is a piece of microwave transmission line with a characteristic impedance defined by its physical dimensions and the PCB material of which it is made. With a transmission line having a characteristic of a distributed set of capacitors and inductors, the transmission line can be tuned to work over a range of frequencies by changing its operating length/width. A capacitor (168) is used to short circuit between the microwave stub (166, 200, 202, 220, 222) and ground (170b), with the position of the capacitor along the microwave stub (166, 200, 202, 220, 222) determining the operating length (and hence the frequency) of the microwave transmission line.

Abstract: A high frequency electronic package (500) having a metal housing (504) and a high frequency electronic component, such as a laser diode, contained within the metal housing (504). One or more leads (508, 510, 512, 514) pass into the metal housing through a header (506) and are coupled to the high frequency electronic component. The leads, metal housing and components within the housing cause stray inductances and capacitances, which cause problems in matching and driving the high frequency electronic component. Therefore a high value capacitor (502) is coupled between the metal housing and an anode lead, as close to the anode as possible, to short the stray capacitances at high frequencies. The capacitor can be a ring capacitor positioned over the anode lead externally of the housing, or can be a plate capacitor mounted internally or externally of the housing.