A method for generating a voltage waveform includes providing an optical signal, which comprises one or more sequences of optical pulses, distributing the optical pulses via optical waveguides to a plurality of optical-to-electrical converter units, using the optical-to-electrical converter units to convert the optical pulses into electric driving current pulses, generating voltage pulses by driving Josephson junctions with the electric driving current pulses.

A signal generator includes a processing unit. The signal generator is configured to generate at least one periodic output signal. The output signal comprises a triangular-waveform signal. A frequency and an amplitude of the output signal are adjustable. The signal generator is configured to receive an input parameter. The input parameter comprises at least one piece of information about a setpoint amplitude and a setpoint frequency of the output signal. The processing unit is configured to determine a signal direction of the output signal. The processing unit is configured to determine a step size. The processing unit is configured to apply the step size to an actual amplitude based on the signal direction for a number of clock cycles. The number of clock cycles is dependent on the setpoint frequency of the output signal.

In some examples, an apparatus comprises: an amplifier having an amplifier output and first and second amplifier inputs, the first amplifier input coupled to a reference voltage terminal, and the second amplifier input coupled to a power input terminal; a ramp generation circuit having a reset input and a ramp output; a comparator having a comparator output and first and second comparator inputs, the first comparator input coupled to the amplifier output, and the second comparator input coupled to the ramp output; and a switching signal generation circuit having a circuit input and a circuit output, the circuit input coupled to the comparator output, and the circuit output coupled to a power control terminal.

In some examples, an apparatus comprises: an amplifier having an amplifier output and first and second amplifier inputs, the first amplifier input coupled to a reference voltage terminal, and the second amplifier input coupled to a power input terminal; a ramp generation circuit having a reset input and a ramp output; a comparator having a comparator output and first and second comparator inputs, the first comparator input coupled to the amplifier output, and the second comparator input coupled to the ramp output; and a switching signal generation circuit having a circuit input and a circuit output, the circuit input coupled to the comparator output, and the circuit output coupled to a power control terminal.

A ramp buffer circuit includes an input device having an input coupled to receive a ramp signal. A bias current source is coupled to an output of the input device. The input device and the bias current source are coupled between a power line and ground. An assist current source is coupled between the output of the input device and ground. The assist current source is configured to conduct an assist current from the output of the input device to ground only during a ramp event generated in the ramp signal.

An inductor current emulator circuit includes a ramp signal generation circuit and an emulator control circuit. The inductor emulator circuit generates a ramp signal for emulating an inductor current flowing through an inductor of a power stage circuit. The ramp signal generation circuit generates the ramp signal according to a first signal and a second signal. A current sense signal is related a high side switch current flowing through the high side switch or a low side switch current flowing through the low side switch. The emulator control circuit obtains a first difference integration value and a second difference integration value of differences between the current sense signal and the ramp signal during a first duration and a second duration, respectively, to generate the first signal and the second signal, respectively. Center time points of the first duration and the second duration are different from each other.

An inductor current emulator circuit includes a ramp signal generation circuit and an emulator control circuit. The inductor emulator circuit generates a ramp signal for emulating an inductor current flowing through an inductor of a power stage circuit. The ramp signal generation circuit generates the ramp signal according to a first signal and a second signal. A current sense signal is related a high side switch current flowing through the high side switch or a low side switch current flowing through the low side switch. The emulator control circuit obtains a first difference integration value and a second difference integration value of differences between the current sense signal and the ramp signal during a first duration and a second duration, respectively, to generate the first signal and the second signal, respectively. Center time points of the first duration and the second duration are different from each other.

An inductor current emulator circuit includes a ramp signal generation circuit and an emulator control circuit. The inductor emulator circuit generates a ramp signal for emulating an inductor current flowing through an inductor of a power stage circuit. The ramp signal generation circuit generates the ramp signal according to a first signal and a second signal. A current sense signal is related a high side switch current flowing through the high side switch or a low side switch current flowing through the low side switch. The emulator control circuit obtains a first difference integration value and a second difference integration value of differences between the current sense signal and the ramp signal during a first duration and a second duration, respectively, to generate the first signal and the second signal, respectively. Center time points of the first duration and the second duration are different from each other.

An inductor current emulator circuit includes a ramp signal generation circuit and an emulator control circuit. The inductor emulator circuit generates a ramp signal for emulating an inductor current flowing through an inductor of a power stage circuit. The ramp signal generation circuit generates the ramp signal according to a first signal and a second signal. A current sense signal is related a high side switch current flowing through the high side switch or a low side switch current flowing through the low side switch. The emulator control circuit obtains a first difference integration value and a second difference integration value of differences between the current sense signal and the ramp signal during a first duration and a second duration, respectively, to generate the first signal and the second signal, respectively. Center time points of the first duration and the second duration are different from each other.

A gate driver circuit includes a first power supply rail providing a first fixed supply voltage; a second power supply rail providing a second fixed supply voltage; a transistor including a gate terminal having a gate voltage; and a gate driver integrated circuit (IC) supplied with the first fixed supply voltage and the second fixed supply voltage, the gate driver IC including an output terminal configured to provide a gate drive voltage at the output terminal in order to drive the transistor between switching states. The gate driver IC includes a first voltage converter configured to modulate an amplitude of the first fixed supply voltage to generate a first modulated supply voltage; and a first switch configured to selectively couple the first fixed supply voltage and the first modulated supply voltage to the output terminal of the gate driver IC in order to regulate the gate drive voltage.