Abstract: A drive circuit of a light emitting element, the drive circuit includes: an input terminal configured to receive an input signal; an output terminal configured to output a signal based on the input signal as a drive signal to the light emitting element; and a main body circuit configured to generate the drive signal by carrying out timing correction to reduce a difference from a standard delay value for rising or falling of a plurality of signal patterns of the input signal regarding a timing of rising of a first signal subsequent to a first signal pattern in the plurality of signal patterns or a timing of falling of a second signal subsequent to a second signal pattern in the plurality of signal patterns.

Abstract: A phase compensation circuit includes: a first circuit that increases phase characteristic of a specific frequency of an electrical signal; a second circuit that decreases the phase characteristic of the specific frequency of the electrical signal; and a limiting amplifier that amplifies an electrical signal that is processed by at least one of the first circuit and the second circuit.

Abstract: A signal recovery circuit includes an oscillator that generates a first clock of which a frequency is variable, and a feedback circuit that controls the oscillator to synchronize the first clock with input data, depending on a phase relationship between the input data and the first clock, the feedback circuit including a control portion that controls the oscillator depending on the phase relationship between the input data and the first clock, a first phase detection circuit that generates a clock phase control signal depending on the phase relationship between the input data and the first clock, an output data generation circuit that generates output data by latching the input data at a change edge of the first clock, and a lock detection circuit that outputs a lock detection signal indicating whether a state is a lock state or a non-lock state.

Abstract: An equalizer circuit includes: a pair of input terminals: a differential amplification circuit outputs, to a pair of output terminals, first signals obtained by amplifying a difference in levels of input signals supplied to the pair of input terminals; and a differential differentiation amplification circuit that outputs, to the pair of output terminals, second signals obtained by amplifying a time-varying change in the difference in the levels of the input signals supplied to the pair of input terminals.

Abstract: An equalizer circuit includes: a pair of input terminals: a differential amplification circuit outputs, to a pair of output terminals, first signals obtained by amplifying a difference in levels of input signals supplied to the pair of input terminals; and a differential differentiation amplification circuit that outputs, to the pair of output terminals, second signals obtained by amplifying a time-varying change in the difference in the levels of the input signals supplied to the pair of input terminals.

Abstract: A current mirror circuit includes: a reference current circuit including a reference transistor and a constant current source coupled between a high potential source and a low potential source; a first proportional current circuit, including a first transistor that forms a first current mirror circuit with the reference transistor, to generate a first current having a first ratio to a reference current of the reference current circuit; a second proportional current circuit, including a second transistor that forms a second current mirror circuit with the reference transistor, to generate a second current having a second ratio to the reference current; a comparison circuit to output a difference between a drain voltage of the first transistor and a drain voltage of the second transistor; and a current adjustment transistor coupled to a drain of the second transistor and including a gate to which an output of the comparison circuit is applied.

Abstract: A current mirror circuit includes: a reference current circuit including a reference transistor and a constant current source coupled between a high potential source and a low potential source; a first proportional current circuit, including a first transistor that forms a first current mirror circuit with the reference transistor, to generate a first current having a first ratio to a reference current of the reference current circuit; a second proportional current circuit, including a second transistor that forms a second current mirror circuit with the reference transistor, to generate a second current having a second ratio to the reference current; a comparison circuit to output a difference between a drain voltage of the first transistor and a drain voltage of the second transistor; and a current adjustment transistor coupled to a drain of the second transistor and including a gate to which an output of the comparison circuit is applied.

Abstract: A signal recovery circuit includes an oscillator configured to control a frequency of generating first clock, and a feedback circuit configured to control the oscillator in order that input data is synchronized with the first clock in accordance with a phase relation between the input data and the first clock, wherein the feedback circuit includes a controller configured to control the oscillator in accordance with the phase relation between the input data and the first clock, a first phase detector configured to generate a clock phase control signal in accordance with the phase relation between the input data and the first clock, and a state detection circuit configured to detect whether the signal recovery circuit is in a locked state or an unlocked state, based on a magnitude of an amplitude of a first component or a second component of the clock phase control signal.

Abstract: A drive circuit of a light emitting element, the drive circuit includes: an input terminal configured to receive an input signal; an output terminal configured to output a signal based on the input signal as a drive signal to the light emitting element; and a main body circuit configured to generate the drive signal by carrying out timing correction to reduce a difference from a standard delay value for rising or falling of a plurality of signal patterns of the input signal regarding a timing of rising of a first signal subsequent to a first signal pattern in the plurality of signal patterns or a timing of falling of a second signal subsequent to a second signal pattern in the plurality of signal patterns.

Abstract: A current mirror circuit includes: a reference current circuit including a reference transistor and a constant current source coupled between a high potential source and a low potential source; a first proportional current circuit, including a first transistor that forms a first current mirror circuit with the reference transistor, to generate a first current having a first ratio to a reference current of the reference current circuit; a second proportional current circuit, including a second transistor that forms a second current mirror circuit with the reference transistor, to generate a second current having a second ratio to the reference current; a comparison circuit to output a difference between a drain voltage of the first transistor and a drain voltage of the second transistor; and a current adjustment transistor coupled to a drain of the second transistor and including a gate to which an output of the comparison circuit is applied.

Abstract: A signal recovery circuit includes: a data acquisition circuit configured to collect a received data signal according to a transition edge of a received signal recovery clock; and a phase adjustment circuit configured to adjust a phase relationship between the transition edge of the received signal recovery clock and the received data signal according to a data value of the received data signal to be acquired by the data acquisition circuit.

Abstract: A phase detection circuit includes: a first circuit configured to generate a first phase detection signal that indicates a result of sampling a first clock signal at a transition timing of an input data signal; a second circuit configured to generate a second phase detection signal that indicates a result of sampling a second clock signal at the transition timing of the input data signal, a phase of the second clock signal being different from a phase of the first clock signal; and a third circuit configured to generate a third phase detection signal that indicates a phase of the first clock signal with respect to the input data signal based on the first phase detection signal and the second phase detection signal.

Abstract: A signal reproduction circuit includes: an oscillator generating first clock and second clock having a same frequency but different phases; and a feedback circuit to control the oscillator in accordance with a phase relation and a frequency relation between input data and the first clock, wherein the feedback circuit includes: a frequency-phase detection circuit to compare a clock phase control signal and a clock phase detection signal and generate a frequency phase signal indicating the frequency relation between the input data and the first clock, a state detection circuit to detect a lock state in which falling edges or rising edges of the input data and the first clock synchronize and a frequency difference state in which frequencies of the input data and the first clock are different, and a selector to supply the frequency phase signal to the feedback loop only in the frequency difference state.

Abstract: A phase detection circuit includes: a first circuit configured to generate a first phase detection signal that indicates a result of sampling a first clock signal at a transition timing of an input data signal; a second circuit configured to generate a second phase detection signal that indicates a result of sampling a second clock signal at the transition timing of the input data signal, a phase of the second clock signal being different from a phase of the first clock signal; and a third circuit configured to generate a third phase detection signal that indicates a phase of the first clock signal with respect to the input data signal based on the first phase detection signal and the second phase detection signal.

Abstract: A multi-lane re-timer circuit includes: a clock generation circuit to generate a base clock; and reception circuits to generate a reception clock and receive input data signals from lanes, wherein each of the reception circuits includes: a phase frequency detector to generate phase difference signal and frequency difference signal between the input data signal and the reception clock; a clock data regeneration controller to generate a control signal based on the phase difference signal; a phase rotator to generate the reception clock from the base clock; and a decision circuit to receive the input data signal, and wherein the clock generation circuit includes: an input selector to select a signal; a charge pump to generate a charge signal; a loop filter to remove a high frequency component from the charge signal to output a voltage control signal; and a voltage controlled oscillator to generate the reception clock.

Abstract: A signal recovery circuit includes: a data acquisition circuit configured to collect a received data signal according to a transition edge of a received signal recovery clock; and a phase adjustment circuit configured to adjust a phase relationship between the transition edge of the received signal recovery clock and the received data signal according to a data value of the received data signal to be acquired by the data acquisition circuit.

Abstract: A phase interpolation clock generator includes: a phase detector configured to detect a phase difference between an input signal and a clock; a phase control signal generator configured to generate a phase control signal that is inverted for a certain phase difference and changes between a high level and a low level based on the phase difference; a controller configured to generate a combining control signal for combining a plurality of phase clocks and performing phase interpolation based on the phase control signal; an overshoot detector configured to detect overshoot in which the phase control signal rises above the high level; an overshoot canceller configured to lower the phase control signal which rises above the high level at an occurrence of the overshoot; and a phase interpolator configured to generate the clock by combining the plurality of phase clocks in accordance with the combining control signal.

Abstract: A drive circuit includes a duty cycle adjusting circuit that changes the duty cycle of a first signal; and a calculating circuit that with respect to signals that include the first signal for which the duty cycle has been adjusted and a second signal having a phase and amplitude that differ from that of the first signal, performs any one of subtracting one of the signals from the other signal and adding the signals.

Abstract: An amplifier circuit includes an amplifier circuit that emitter-grounds a first transistor that amplifies an input signal; and an emitter-grounded feedback circuit in which a collector of the first transistor is connected to an output line of the amplifier circuit and a base is wiring-connected only to the output line by using a resistor.

Abstract: An emphasis signal generating circuit includes: a branch and delay unit configured to branch an input signal, delay a branched signal, and output a first delayed signal; a high-frequency extraction unit configured to extract at least one of high-frequency components of the input signal and the first delayed signal to output a high-frequency signal; and an addition and subtraction unit configured to add and subtract the input signal, the first delayed signal, and the high-frequency signal.