Abstract: A system for transmitting an optical signal between a host and a device according to a SATA protocol. The system comprises a transmitting-side converter for generating a logic one voltage value responsive to a data one value from an information source, for generating a logic zero voltage value responsive to a data zero value from the information source, for generating an idle state logic voltage value, wherein the idle state logic voltage value is (logic one voltage value+logic zero voltage value)/2, the transmitting-side converter comprising only linear functions to preserve the idle state logic voltage value, and an electrical-to-optical converter for converting the logic one, logic zero and the idle state logic voltage values to an optical signal further comprising respective logic one, logic zero and idle state optical values and for supplying the optical signal to an optical communications medium.

Abstract: A system for transmitting an optical signal between a host and a device according to a SATA protocol. The system comprises a transmitting-side converter for generating a logic one voltage value responsive to a data one value from an information source, for generating a logic zero voltage value responsive to a data zero value from the information source, for generating an idle state logic voltage value, wherein the idle state logic voltage value is (logic one voltage value+logic zero voltage value)/2, the transmitting-side converter comprising only linear functions to preserve the idle state logic voltage value, and an electrical-to-optical converter for converting the logic one, logic zero and the idle state logic voltage values to an optical signal further comprising respective logic one, logic zero and idle state optical values and for supplying the optical signal to an optical communications medium.

Abstract: A method and apparatus for converting DC electricity to AC electricity, the AC electricity having a sine wave shape. DC electricity is supplied to a pulse width modulator. A pulse width modulated signal is formed from the DC electricity, the pulse width modulated signal comprising a plurality of pulses, each pulse having a duration representing an amplitude of the sine wave during an interval of the sine wave represented by the pulse, the pulse width modulated signal comprising a plurality of pulses (or a pulse train) during one sine wave period. The sine wave is generated from the pulse width modulated signal, values of the sine wave during successive sine wave intervals responsive to the duration of the pulse that represents the sine wave interval.

Abstract: A method and apparatus for converting DC electricity to AC electricity, the AC electricity having a sine wave shape. DC electricity is supplied to a pulse width modulator. A pulse width modulated signal is formed from the DC electricity, the pulse width modulated signal comprising a plurality of pulses, each pulse having a duration representing an amplitude of the sine wave during an interval of the sine wave represented by the pulse, the pulse width modulated signal comprising a plurality of pulses (or a pulse train) during one sine wave period. The sine wave is generated from the pulse width modulated signal, values of the sine wave during successive sine wave intervals responsive to the duration of the pulse that represents the sine wave interval.

Abstract: A method of, and an apparatus for, biasing photodiodes used in optical receivers or optical transceivers includes an electronic circuit for generating a bias voltage for the photodiode and a processor having a pulse-width modulation unit that produces pulse-width modulated pulses at a predetermined number of duty cycle values M. The processor is coupled to the electronic circuit such that a magnitude of the bias voltage is dependent upon a duty cycle value of at least one of the pulse-width modulated pulses. Advantageously, the processor includes a program for modulating the pulse-width modulated pulses generated by the processor between two different duty cycle values such that a number of obtainable bias voltages is greater than M. The result is a significant reduction in the number of necessary components.

Abstract: An optical monitoring circuit includes a photoelectric device such as a photo-detector that produces a signal in response to incident light thereon corresponding to a characteristic of the incident light such as intensity, or wavelength. A light source is disposed within the circuit for emitting a beam of light, a portion of which is to be incident upon the photoelectric device. The photoelectric device when reversed biased provides an output electrical signal from which the intensity of light from the light source impinging thereon can be determined. The photoelectric device when forward biased provides an output signal from which the temperature of the photoelectric device can be determined. A method and circuit are disclosed for calibrating out the unwanted effect of light from the light source affecting accuracy of the determined temperature derived from the output signal when the photoelectric device is forward biased.

Abstract: An optical monitoring circuit includes a photoelectric device such as a photo-detector that produces a signal in response to incident light thereon corresponding to a characteristic of the incident light such as intensity, or wavelength. A light source is disposed within the circuit for emitting a beam of light, a portion of which is to be incident upon the photoelectric device. The photoelectric device when reversed biased provides an output electrical signal from which the intensity of light from the light source impinging thereon can be determined. The photoelectric device when forward biased provides an output signal from which the temperature of the photoelectric device can be determined. A method and circuit are disclosed for calibrating out the unwanted effect of light from the light source affecting accuracy of the determined temperature derived from the output signal when the photoelectric device is forward biased.

Abstract: A phase lock loop (PLL) circuit and method in which a PLL circuit locks on a variable input phase by providing an instantaneous phase value of a signal from an oscillator at periodic intervals, and by providing phase corrective signals to the oscillator at the same periodic intervals by comparing an instantaneous value of the variable phase to the corresponding instantaneous value of the oscillator signal phase, the phase corrective signals adjusting the phase of the oscillator signal to the predetermined phase. The PLL circuit may also lock on a predetermined frequency by providing frequency corrective signals until a difference between the predetermined frequency and the frequency of oscillator signal is smaller than a predetermined threshold.