Abstract: A method of controlling a laser driver includes determining a set of timing parameters in response to contents of a received bit stream. The method further includes creating a plurality of sets of pulse defining parameters in response to the set of timing parameters, and generating a plurality of generic pulses in response to the plurality of sets of pulse defining parameters. The method also includes combining the plurality of generic pulses into a plurality of enable signals, and creating a plurality of adapted enable signals by selectively replacing one of the plurality of enable signals with an alternative signal. The method further includes outputting the plurality of adapted enable signals to the laser driver.

Abstract: In an apparatus for conditioning a signal from an optical pickup unit (OPU), a single-ended channel includes a first signal processing block to calibrate a dark level of a single-ended signal corresponding to a single-ended output of the OPU, if any, and to center the single-ended signal. A dual-ended channel includes a second signal processing block to calibrate a dark level of a dual-ended signal corresponding to a dual-ended output of the OPU, if any, and to center the dual-ended signal. A multiplexer selects one of the single-ended channel and the dual-ended channel, and outputs a selected signal. A digital signal processing stage converts the selected signal to a digital signal.

Abstract: The following embodiments relate to an analog filter having an adjustable transfer function for use in a system or circuit that processes a signal having a changing data rate. The transfer function may be adjusted by adjusting the resistance and/or capacitance of components of the analog filter. The analog filter is calibrated based on an optimum operational parameter at a certain data rate, such as a median data rate. The analog filter may be further adjusted as the data rate of the signal changes.

Abstract: A driver comprising: a pattern module configured to generate a plurality of timing parameters in response to a received bit stream; a timing module configured to determine a plurality of multi-bit parameters in response to the timing parameters; and a pulse module configured to (i) generate each of a plurality of pulses in response to a different one of the plurality of multi-bit parameters, (ii) generate each of a plurality of enable signals in response to a variable combination of the plurality of pulses, and (iii) output the plurality of enable signals to a laser driver.

Abstract: In one embodiment, a phase detector is provided comprising a first input, a second input, and first circuitry in communication with the first and second inputs, the first circuitry operative to provide an indication of a phase difference between a first signal supplied by the first input and a second signal supplied by the second input, wherein an aberration in one of the first and second signals results in an incorrect indication of phase difference. The phase detector also comprises second circuitry in communication with the first circuitry, the second circuitry operative to provide a correct indication of phase difference despite the aberration in the at least one of the first and second signals. In another embodiment, a differential phase detector is provided.

Abstract: Systems, methods and computer program products for correcting polarity decision associated with a polarity comparator in an analog-to-digital converter are described. The polarity comparator may perform polarity decision to determine whether an analog signal is greater or smaller than zero. If the voltage difference is greater than zero, then the analog signal may be output to other comparators without polarity inversion. If the voltage difference is smaller than zero, then the signal polarity of the analog signal may be inverted before being output to other comparators. One or more redundant comparators also may be used to correct offsets of the polarity comparator to reduced errors associated with the polarity decision.

Abstract: A driver includes a parameter generation module configured to generate timing parameters based upon a received bit stream. A timing encoding module is configured to determine a plurality of pulse defining parameters based on the timing parameters. A pulse generation module is configured to determine a plurality of generic pulses based on the plurality of pulse defining parameters. The pulse generation module is configured to combine the plurality of generic pulses into a plurality of enable signals. The pulse generation module is configured to selectively invert a first enable signal of the plurality of enable signals. The pulse generation module is configured to output the plurality of enable signals including the first enable signal to a laser driver.

Abstract: A driver circuit for use with a variety of OPU circuits has both a single-ended input and a differential input. The single-ended input is coupled to a single-ended signal path having a variable gain stage and a variable level shifter. The differential input is coupled to a differential signal path having a variable gain stage and a variable level shifter. The single-ended signal path and the differential signal path may be selectively coupled to an output. The respective variable gain stages and variable level shifters can be adjusted so that an output signal at the output has a desired dynamic range.

Abstract: In one embodiment, a phase detector is provided comprising a first input, a second input, and first circuitry in communication with the first and second inputs, the first circuitry operative to provide an indication of a phase difference between a first signal supplied by the first input and a second signal supplied by the second input, wherein an aberration in one of the first and second signals results in an incorrect indication of phase difference. The phase detector also comprises second circuitry in communication with the first circuitry, the second circuitry operative to provide a correct indication of phase difference despite the aberration in the at least one of the first and second signals. In another embodiment, a differential phase detector is provided.

Abstract: A driver control module comprises a parameter generation module, a timing encoding module, and a pulse generation module. The parameter generation module receives a bit stream and generates a set of timing parameters based upon contents of the bit stream. The timing encoding module receives the set of timing parameters from the parameter generation module and creates N sets of pulse defining parameters, wherein N is an integer greater than one. The pulse generation module creates N generic pulses using the sets of pulse defining parameters, combines the generic pulses into P enable signals, and outputs the enable signals to a laser driver, wherein P is an integer greater than one.

Abstract: To detect the peaks level of an incoming signal, the difference between the voltage level of the incoming signal and a voltage developed across a capacitor is amplified. The amplified difference signal is applied to a transconductor adapted to vary its output current in response to changes in the amplified difference signal. The variations in the current generated by the transconductor are used to change a current flowing through a current mirror that charges the capacitor. The voltage developed across the capacitor represents the detected peak. The capacitor is discharged to a predefined voltage level during the reset periods. A second amplifier receiving the capacitor voltage is optionally used to develop a voltage across a second capacitor that is not reset and thus carries only the detected peak levels.

Abstract: AFE circuitry handles both voltage and current input signals. In one embodiment, both a voltage path and a current path are provided from the input. Switching circuitry selects one of the paths. A switch also turns on or off a current-to-voltage conversion circuit used to convert a current input into a voltage. In one embodiment, noise is significantly reduced by using a dedicated ground pin or terminal for the negative reference of a differential circuit. This applies the same external board noise, which is on the input signal, to the negative reference, so the noise is canceled in the differential signal. In one embodiment, temperature compensation is provided via an IPTAT circuit which is used to shift the voltage up in order to balance the decrease in DC voltage with increasing temperature.

Abstract: Circuitry and methods are provided for continuously adjustable frequency synthesis. The synthesis covers a wide range of possible frequencies and can be performed to a high degree of precision. In an embodiment of the invention, an analog phase-locked loop (“PLL”) performs relatively coarse wide-range frequency synthesis, while a digital PLL performs relatively fine narrow-range frequency synthesis and phase alignment. The analog PLL is capable of varying frequency in a stepwise linear fashion. The digital PLL communicates with the analog PLL to ensure that the output of the analog PLL is within the digital PLL's specified pull-in range.

Abstract: Circuitry and methods are provided for continuously adjustable frequency synthesis. The synthesis covers a wide range of possible frequencies and can be performed to a high degree of precision. In an embodiment of the invention, an analog phase-locked loop (“PLL”) performs relatively coarse wide-range frequency synthesis, while a digital PLL performs relatively fine narrow-range frequency synthesis and phase alignment. The analog PLL is capable of varying frequency in a stepwise linear fashion. The digital PLL communicates with the analog PLL to ensure that the output of the analog PLL is within the digital PLL's specified pull-in range.

Abstract: A pseudo-differential signaling system uses a plurality of signal lines and a single, common reference voltage. Signal line voltages are interpreted only in comparison to the reference line voltage. Within a receiving circuit, the reference line is buffered prior to its distribution to multiple comparators. The system utilizes an active buffer having a bandwidth that is significantly greater than the resonant input frequency of the receiving circuit. In an alternative embodiment, the signal lines are also buffered. In this embodiment, the buffers are implemented with transistor-based source-followers. The buffer associated with the reference line has a larger current capacity than the buffers associated with the signal lines. In yet another embodiment, a comparator produces a correction signal that is equal to the noise present on the signal lines. This noise is then subtracted from the signal voltages.

Abstract: A circuit, apparatus and method for efficiently and accurately calibrating an output driver current are provided in embodiments of the present invention. In an embodiment of the present invention, a circuit comprises a first digital-to-analog converter (“DAC”) that generates a first current. A first transistor is coupled to the first DAC and generates a first biasing current responsive to the first current. A second DAC is coupled to the first transistor and generates a first control current responsive to the first biasing current. According to an embodiment of the present invention, the first and second DACs are binary weighted control DACs. According to an embodiment of the present invention, the binary weighted values of the second DAC are obtained in response to a calibration signal generated by a controller. According to an embodiment of the present invention, the first DAC is an M-bit DAC and the second DAC is an N-bit DAC, wherein M is less than N.

Abstract: A circuit, apparatus and method for efficiently and accurately calibrating an output driver current are provided in embodiments of the present invention. In an embodiment of the present invention, a circuit comprises a first digital-to-analog converter (“DAC”) that generates a first current. A first transistor is coupled to the first DAC and generates a first biasing current responsive to the first current. A second DAC is coupled to the first transistor and generates a first control current responsive to the first biasing current. According to an embodiment of the present invention, the first and second DACs are binary weighted control DACs. According to an embodiment of the present invention, the binary weighted values of the second DAC are obtained in response to a calibration signal generated by a controller. According to an embodiment of the present invention, the first DAC is an M-bit DAC and the second DAC is an N-bit DAC, wherein M is less than N.

Abstract: A circuit, apparatus and method for efficiently and accurately calibrating an output driver current are provided in embodiments of the present invention. In an embodiment of the present invention, a circuit comprises a first digital-to-analog converter (“DAC”) that generates a first current. A first transistor is coupled to the first DAC and generates a first biasing current responsive to the first current. A second DAC is coupled to the first transistor and generates a first control current responsive to the first biasing current. According to an embodiment of the present invention, the first and second DACs are binary weighted control DACs. According to an embodiment of the present invention, the binary weighted values of the second DAC are obtained in response to a calibration signal generated by a controller. According to an embodiment of the present invention, the first DAC is an M-bit DAC and the second DAC is an N-bit DAC, wherein M is less than N.

Abstract: Circuits, architectures, and methods for tracking a phase locked loop (PLL) configuration such that its VCO gain is essentially a linear function of its feedback divider factor over a wide frequency range. The circuit generally includes an oscillator loop having (2n+1) stages, where n is an integer of at least 1, and at least three of the stages comprise a delay circuit and a characteristic control circuit configured to (i) receive divider information and (ii) set or change a delay characteristic of the delay circuit in response to the divider information. The architectures generally relate to PLLs that include a circuit embodying one or more of the inventive concepts disclosed herein. The method generally includes the steps of generating a periodic signal from an oscillator, dividing the periodic signal by a first number, and setting a characteristic property of at least part of the oscillator in accordance with the first number.

Abstract: A circuit, apparatus and method for efficiently and accurately calibrating an output driver current are provided in embodiments of the present invention. In an embodiment of the present invention, a circuit comprises a first digital-to-analog converter (“DAC”) that generates a first current. A first transistor is coupled to the first DAC and generates a first biasing current responsive to the first current. A second DAC is coupled to the first transistor and generates a first control current responsive to the first biasing current. According to an embodiment of the present invention, the first and second DACs are binary weighted control DACs. According to an embodiment of the present invention, the binary weighted values of the second DAC are obtained in response to a calibration signal generated by a controller. According to an embodiment of the present invention, the first DAC is an M-bit DAC and the second DAC is an N-bit DAC, wherein M is less than N.