摘要:
A charge pump circuit, connected between a first voltage reference and an output terminal, comprises at least two parallel-coupled stages having an elementary charge pump circuit connected between said first voltage reference and said output terminal, and adjustment circuitry connected between said output terminal and respective control terminals of said at least two stages. This adjustment circuitry is arranged to select for actuation an appropriate combination of these elementary stages according to the current absorbed from a load connected to the output terminal.
摘要:
A charge pump voltage booster circuit for generating, from a first voltage supplied at the input to the circuit, an output voltage with an absolute value that is higher than the first voltage, comprises at least one stage having a charge pass element and a charge storage capacitor with a first plate connected to an output of the charge pass element and a second plate controlled by a square-wave control signal of period varying between a reference voltage and the first voltage, supplied to the second plate of the capacitor by means of a driver circuit comprising a pull-up transistor and a pull-down transistor connected in series between the first voltage and the reference voltage. Means of overdriving at least one of the said transistors, either the pull-up transistor or the pull-down transistor, supply to the said at least one transistor a firing control voltage that has a higher absolute value than the first voltage.
摘要:
Various systems and methods are provided to achieve laser power control. In one embodiment, a system is provided that comprises a counter that holds a digital value. An digital-to-analog converter is employed to convert the digital value to an analog current. A data threshold current is generated by a laser driver based upon the analog current. The data threshold current is employed to represent a data value in a data signal employed to drive a laser diode. Also, circuitry is employed to adjust the digital value based upon a comparison between a target threshold current and a feedback current generated from a laser output of the laser diode.
摘要:
A trans-impedance amplifier receives an input current and is operable to generate an output voltage responsive to the input current. The amplifier is responsive to an increased range of input currents and has a wide bandwidth. The amplifier includes an input stage having a first and a second transistor and is configured to receive the input current. The amplifier includes an output stage coupled to the input stage and having a third and a fourth transistor. A variable resistor is coupled to the output stage to adjust the amount of current in the output stage. A variable current source is coupled to the output stage and is operable to adjust the amount of current in the output stage. A output driver, which is coupled to the output stage, includes at least another transistor. The output driver is operable to provide the output voltage and is operable to reduce the output impedance of the amplifier.
摘要:
Various systems and methods are provided to achieve laser power control. In one embodiment, a system is provided that comprises a counter that holds a digital value. An digital-to-analog converter is employed to convert the digital value to an analog current. A data threshold current is generated by a laser driver based upon the analog current. The data threshold current is employed to represent a data value in a data signal employed to drive a laser diode. Also, circuitry is employed to adjust the digital value based upon a comparison between a target threshold current and a feedback current generated from a laser output of the laser diode.
摘要:
A trans-impedance amplifier receives an input current and is operable to generate an output voltage responsive to the input current. The amplifier is responsive to an increased range of input currents and has a wide bandwidth. The amplifier includes an input stage having a first and a second transistor and is configured to receive the input current. The amplifier includes an output stage coupled to the input stage and having a third and a fourth transistor. A variable resistor is coupled to the output stage to adjust the amount of current in the output stage. A variable current source is coupled to the output stage and is operable to adjust the amount of current in the output stage. A output driver, which is coupled to the output stage, includes at least another transistor. The output driver is operable to provide the output voltage and is operable to reduce the output impedance of the amplifier.