An important component in digital circuits is a phase rotator, which permits precise time-shifting (or equivalently, phase rotation) of a clock signal within a clock period. A digital phase rotator can access multiple discrete values of phase under digital control. Such a device can have application in digital clock synchronization circuits, and can also be used for a digital phase modulator that encodes a digital signal. A digital phase rotator has been implemented in superconducting integrated circuit technology, using rapid single-flux-quantum logic (RSFQ). This circuit can exhibit positive or negative phase shifts of a multi-phase clock. Arbitrary precision can be obtained by cascading a plurality of phase rotator stages. Such a circuit forms a phase-modulator that is the core of a direct digital synthesizer that can operate at multi-gigahertz radio frequencies.

A circuit includes a first switch, a second switch, a first delay circuit and a second delay circuit. The first switch includes a first terminal, and the second switch includes a second terminal. The first delay circuit is coupled to the first terminal and the second terminal. The first delay circuit is configured to alternately turn ON the first switch and the second switch in accordance with an input signal and with a delay between successive ON times of the first switch and the second switch. The second delay circuit is coupled to the first terminal and the second terminal. The second delay circuit is configured to control the first delay circuit to generate the delay in accordance with a stored setting of the delay, a first voltage on the first terminal, or a second voltage on the second terminal.

A circuit includes a first switch, a second switch, a first delay circuit and a second delay circuit. The first switch includes a first terminal, and the second switch includes a second terminal. The first delay circuit is coupled to the first terminal and the second terminal. The first delay circuit is configured to alternately turn ON the first switch and the second switch in accordance with an input signal and with a delay between successive ON times of the first switch and the second switch. The second delay circuit is coupled to the first terminal and the second terminal. The second delay circuit is configured to control the first delay circuit to generate the delay in accordance with a stored setting of the delay, a first voltage on the first terminal, or a second voltage on the second terminal.

The present document relates to a timer which is counter-based and uses an asynchronous circuitry to improve the accuracy between the available clock cycles. In particular, a timer is presented which may comprise a first timer circuit configured to receive a clock signal and a trigger signal, wherein an edge of the trigger signal arrives after a first edge of the clock signal and before a second edge of the clock signal. The first timer circuit may be configured to determine, in a capture phase, a time offset interval for approximating a time interval between the first edge of the clock signal and the edge of the trigger signal.

The present document relates to a timer which is counter-based and uses an asynchronous circuitry to improve the accuracy between the available clock cycles. In particular, a timer is presented which may comprise a first timer circuit configured to receive a clock signal and a trigger signal, wherein an edge of the trigger signal arrives after a first edge of the clock signal and before a second edge of the clock signal. The first timer circuit may be configured to determine, in a capture phase, a time offset interval for approximating a time interval between the first edge of the clock signal and the edge of the trigger signal.

A phase interpolator is provided with a plurality of slices. Each slice includes a first switch for mixing a first clock signal into an interpolated output signal and a second switch for mixing a second clock signal into the interpolated output signal. In response to a high-resolution signal, at least one of the slices may switch on both the first switch and the second switch.

In described examples, a pulse width modulation (PWM) system includes an initiator and a receiver. The initiator includes an initiator counter and an initiator PWM signal generator. The initiator counter advances an initiator count in response to an initiator clock signal. The initiator PWM signal generator generates an initiator PWM signal in response to the initiator count. The receiver includes a receiver counter, a receiver PWM signal generator, and circuitry configured to reset the receiver count. The receiver counter advances a receiver count in response to a receiver clock signal. The receiver PWM signal generator generates a receiver PWM signal in response to the receiver count. The circuitry resets the receiver count in response to a synchronization signal and based on an offset.

Apparatus and methods for a digital-to-time converter (DTC) are provided. In an example, a DTC can include a phase interpolator and a ring oscillator. The phase interpolator can be configured to receive digital representations of two or more distinct phase signals, and to interpolate the digital representations of the two or more distinct phase signals to provide an interpolated output phase signal. The ring oscillator can be configured to receive the interpolated phase signal, to lock on to a frequency and a phase of the interpolated output phase signal, and to provide a filtered phase signal.

This application relates to time-encoding modulators (TEMs). A TEM (100) receives an input signal (S.sub.IN) and outputs a time encoded signal (S.sub.PWM). A comparator (101) is located within a forward signal path of a feedback loop of the TEM. Also in the feedback loop are a filter (104) and a delay element (106) for applying a controlled delay. In some embodiments a latching element (101, 302; 106, 402) is located within the forward signal path to synchronise any signal transitions output from the latching element to a received first clock signal. Any signal transitions in the output (S.sub.OUT) from the modulator are thus synchronised to the first clock signal. In some embodiments the delay element (106) is a digital delay element which is synchronised to the first clock signal.

This application relates to time-encoding modulators (TEMs). A TEM (100) receives an input signal (S.sub.IN) and outputs a time encoded signal (S.sub.PWM). A comparator (101) is located within a forward signal path of a feedback loop of the TEM. Also in the feedback loop are a filter (104) and a delay element (106) for applying a controlled delay. In some embodiments a latching element (101, 302; 106, 402) is located within the forward signal path to synchronise any signal transitions output from the latching element to a received first clock signal. Any signal transitions in the output (S.sub.OUT) from the modulator are thus synchronised to the first clock signal. In some embodiments the delay element (106) is a digital delay element which is synchronised to the first clock signal.